FEBS Letters RSS feed: Articles in Press. FEBS Letters is one of the world's leading journals in biochemistry and is renowned both for its quality of content and speed of production. Bringing together the most important developments in the molecular biosciences, FEBS Letters provides an international forum for Minireviews, hypotheses and research letters that merit urgent publication. FEBS Letters offers: • Faster publication: ? Accepted articles are published online in 3 days ? The print version of the article is published in 3 to 5 weeks after acceptance • Full-text article disclosure in HTML and PDF formats • Articles in Press are included in PubMed • Easy online manuscript submission system • Transparent online peer review and manuscript tracking system • No page charges • Free color figures Subject Coverage: The subject area of FEBS Letters is broad. It covers biochemistry (including protein chemistry, enzymology, nucleic acid chemistry, metabolism, and immunochemistry), structural biology, biophysics, computational biology (genomics, proteomics, bioinformatics), molecular genetics, molecular biology and molecular cell biology (signal transduction, intracellular traffic, regulation of cellular proliferation, cell-cell interactions) and systems biology. Studies on microbes, plants and animals at the molecular level are within the scope of FEBS Letters. Submitting Authors: Manuscripts can be submitted to FEBS Letters at: http://ees.elsevier.com/febsletters/ http://www.febsletters.org//inpress?rss=yesElsevier Inc.en © 2012 Federation of European Biochemical Societies. Published by Elsevier Inc. All rights reserved. FEBS Letters0014-57932012-02-06 © 2012 Federation of European Biochemical Societies. Published by Elsevier Inc. All rights reserved. healthpermissions@elsevier.comhttp://www.febsletters.org/article/PIIS0014579312001019/abstract?rss=yesAbstract: TGFβ signaling Smads (Smad2, 3, and 4) were suspected tumor suppressors soon after their discovery. Nearly two decades of research confirmed this role and revealed other divergent and cancer-specific functions including paradoxical tumor promotion effects. Although Smad4 is the most potent tumor suppressor, its functions are highly context-specific as exemplified by pancreatic cancer and head-and-neck cancer: in pancreatic cancer, Smad4 loss cannot initiate tumor formation but promotes metastases while in head-and-neck cancer Smad4 loss promotes cancer progression but also initiates tumor formation, likely through effects on genomic instability. The differing consequences of impaired Smad signaling in human cancers and the molecular mechanisms that underpin these differences will have important implications for the design and application of novel targeted therapies.Two sides of the story? Smad4 loss in pancreatic cancer versus head-and-neck cancer - Accepted ManuscriptStephen P. Malkoski, Xiao-Jing Wang10.1016/j.febslet.2012.01.054FEBS Letters (2012)2012-02-06FEBS Letters2012-02-06http://www.febsletters.org/article/PIIS0014579312001020/abstract?rss=yesHighlights: ► TNF-α-induced ROS activates Syk and PI3K. ► These are required to activate AP-1 and subsequent ET-1. ► ET-1 is implicated in the pathogenesis of atherosclerosis. ► Syk could be a possible new target for prevention of atherosclerosis.Abstract: Endothelin-1 (ET-1) promotes atherosclerosis. We tested whether spleen tyrosine kinase (Syk) mediates tumor necrosis factor-α (TNF-α)-induced ET-1 upregulation in human aortic endothelial cells (HAECs) and sought to identify the signal pathways involved. TNF-α-induced reactive oxygen species (ROS) activated Syk and phosphatidylinositol 3-kinase (PI3K), which was required for the activation of AP-1 and subsequent ET-1 gene transcription. ROS mediated c-Jun NH2-terminal kinase (JNK) is also required for AP-1 activation, but Syk and PI3K regulated AP-1 activation independently of JNK. Through regulation of ET-1 production, Syk could be implicated in atherosclerosis.Activation of spleen tyrosine kinase is required for TNF-α-induced endothelin-1 upregulation in human aortic endothelial cells - Accepted ManuscriptYoon Ji Kim, Tai Yeon Koo, Won Seok Yang, Nam Jeong Han, Jin Uk Jeong, Sang Koo Lee, Su-Kil Park10.1016/j.febslet.2012.01.055FEBS Letters (2012)2012-02-06FEBS Letters2012-02-06http://www.febsletters.org/article/PIIS0014579312001032/abstract?rss=yesHighlights: ► The respiratory complex I contains an unusual, horizontal’ helix on subunit NuoL. ► We mutated residues of the helix to investigate their role in proton translocation. ► The variants D563X[L] (X=E, N, Q and A) showed a reduced H[+]/e[-] stoichiometry. ► D542[L] is involved in proton transfer to the membranous translocation site.Abstract: The NADH:ubiquinone oxidoreductase couples the electron transfer from NADH to ubiquinone with the translocation of protons across the membrane. It contains a 110 Å long helix running parallel to the membrane part of the complex. Deletion of the helix resulted in a reduced H+/e- stoichiometry indicating its direct involvement in proton translocation. Here, we show that the mutation of the conserved amino acid D563L, which is part of the horizontal helix of the Escherichia coli complex I, leads to a reduced H+/e- stoichiometry. It is discussed that this residue is involved in transferring protons to the membranous proton translocation site.Asp563 of the horizontal helix of subunit NuoL is involved in proton translocation by the respiratory complex I - Accepted ManuscriptStefan Steimle, Max Willistein, Patricia Hegger, Marco Janoschke, Heiko Erhardt, Thorsten Friedrich10.1016/j.febslet.2012.01.056FEBS Letters (2012)2012-02-06FEBS Letters2012-02-06http://www.febsletters.org/article/PIIS0014579312000580/abstract?rss=yesHighlights: ► miR-222 is up-regulated both by H. pylori infection and in gastric cancer. ► Over-expression of miR-222 promotes cell proliferation and colony formation. ► RECK is a novel target of miR-222 and inversely correlated with miR-222. ► RECK is involved in miR-222-regulated proliferation in gastric cancer cells.Abstract: Little is known about the potential role of microRNAs (miRNAs) in the carcinogenesis of gastric cancer induced by Helicobacter pylori (H. pylori). Here, we showed that microRNA-222 (miR-222) was up-regulated in H. pylori-infected gastric mucosa and gastric cancer. Ectopic expression of miR-222 promoted cell proliferation and colony formation in vitro. Mechanistically, we identified RECK as a novel target of miR-222, and also confirmed their relationship by the inverse correlation of mRNA expression ex vivo. Furthermore, we found that RNA interference silencing of RECK can mimic the oncogenic effects of miR-222. Collectively, H. pylori may function as an initiator in the process of carcinogenesis by up-regulating miR-222, which further participates in the progression of cancer by promoting proliferation and inhibiting RECK.Increased miR-222 in H. pylori-associated gastric cancer correlated with tumor progression by promoting cancer cell proliferation and targeting RECK - Uncorrected ProofNa Li, Bin Tang, En-Dong Zhu, Bo-sheng Li, Yuan Zhuang, Shu Yu, Dong-shui Lu, Quan-Ming Zou, Bin Xiao, Xu-Hu Mao10.1016/j.febslet.2012.01.025FEBS Letters (2012)2012-02-03FEBS Letters2012-02-03http://www.febsletters.org/article/PIIS0014579312000774/abstract?rss=yesHighlights: ► ATX and LPA3 are coordinately up-regulated by LPS in human monocytic THP-1 cells. ► PKR-mediated JNK1 and p38 MAPK activation is required for ATX and LPA3 induction. ► SPK1-mediated PI3K–AKT–β-catenin pathway activation is required for ATX induction. ► SPK1-mediated ERK activation is required for LPA3 up-regulation by LPS in THP-1 cells. ► Either ATX or LPA3 knockdown inhibits the CCL8 induction by LPS in THP-1 cells.Abstract: Lysophosphatidic acid (LPA) is an important phospholipid mediator in inflammation and immunity. Previously, we showed that autotaxin (ATX), the enzyme producing LPA from lysophosphatidylcholine (LPC), is induced by LPS in THP-1 cells via the activation of PKR, JNK and p38 MAPK. In this study, we find that ATX and LPA receptor 3 (LPA3) are coordinately up-regulated in LPS-stimulated THP-1 cells. PKR-mediated activation of JNK1 and p38 MAPK is required for both ATX and LPA3 up-regulation. SPK1-mediated activation of the PI3K-AKT-β-catenin pathway is essential for ATX induction, while SPK1-mediated ERK activation is required for LPA3 up-regulation. Either ATX or LPA3 knockdown inhibited CCL8 induction by LPS, suggesting that ATX and LPA3 are involved in CCL8 induction during the inflammatory process against bacterial infection.ATX and LPA receptor 3 are coordinately up-regulated in lipopolysaccharide-stimulated THP-1 cells through PKR and SPK1-mediated pathways - Uncorrected ProofSong Li, Chaoyang Xiong, Junjie Zhang10.1016/j.febslet.2012.01.044FEBS Letters (2012)2012-02-03FEBS Letters2012-02-03http://www.febsletters.org/article/PIIS0014579312000798/abstract?rss=yesHighlights: ► Mutations at Pro42 and Val45 of SAK abrogate its Pg activation property. ► Pro42 and Val45 modulate contacts of His43–Tyr44 pair of SAK with Trp215 of plasmim. ► His43 is vulnerable than Tyr44 to local changes at the interface of SAK–Pm complex.Abstract: Staphylokinase (SAK) forms a 1:1 stoichiometric complex with plasmin (Pm) and changes its substrate specificity to create a plasminogen (Pg) activator complex. The His43–Tyr44 pair of SAK resides within the active site cleft of the partner Pm and generates intermolecular contacts to confer Pg activator ability to the SAK–Pm bimolecular complex. Site-directed mutagenesis and molecular modeling studies unravelled that mutation at 42nd or 45th positions of SAK specifically disrupts cation-pi interaction of His43 with Trp215 of partner Pm within the active site, whereas pi–pi interaction of Tyr44 with Trp215 remain energetically favoured.Structured summary of protein interactions: Pg binds to SAK by surface plasmon resonance (View Interaction: 1, 2, 3)SAK enzymaticly reacts Pg by enzymatic study (View Interaction: 1, 2, 3, 4, 5)Pro42 and Val45 of staphylokinase modulate intermolecular interactions of His43–Tyr44 pair and specificity of staphylokinase–plasmin activator complex - Uncorrected ProofSatish Singh, F.N.U. Ashish, Kanak L. Dikshit10.1016/j.febslet.2012.01.046FEBS Letters (2012)2012-02-03FEBS Letters2012-02-03http://www.febsletters.org/article/PIIS0014579312000853/abstract?rss=yesHighlights: ► First report of novel agonistic and antagonistic scFvs against LHR Hinge region. ► Discontinuous epitope of agonistic scFv comprises regions in both Cb-2 and Cb-3. ► Development of inverse agonistic MAb PD1.37 specific to Cb-3 of TSHR hinge region. ► Inhibition of basal activity of TSHR activating mutations by MAb PD1.37. ► Demonstration of differential interplay of hinge subdomains of LHR and TSHR.Abstract: We report two antibodies, scFv 13B1 and MAb PD1.37, against the hinge regions of LHR and TSHR respectively, which have similar epitopes but different effects on receptor function. While neither of them affected hormone binding, with marginal effects on hormone response, scFv 13B1 stimulated LHR in a dose-dependent manner, whereas MAb PD1.37 acted as an inverse agonist of TSHR. Moreover, PD1.37 could decrease the basal activity of hinge region CAMs, but had varied effects on those present in ECLs, whereas 13B1 was refractory to any CAMs in LHR. Using truncation mutants and peptide phage display, we compared the differential roles of the hinge region cysteine box-2/3 as well as the exoloops in the activation of these two homologus receptors.Insights into differential modulation of receptor function by hinge region using novel agonistic lutropin receptor and inverse agonistic thyrotropin receptor antibodies - Accepted ManuscriptRitankar Majumdar, Reema Railkar, Rajan R Dighe10.1016/j.febslet.2012.01.052FEBS Letters (2012)2012-02-03FEBS Letters2012-02-03http://www.febsletters.org/article/PIIS0014579312000865/abstract?rss=yesAbstract: Yeast species such as Saccharomyces cerevisiae have been exploited by humans for millennia and so it is therefore unsurprising that they are attractive cells to re-engineer for industrial use. Despite many beneficial traits yeast has for synthetic biology, it currently lags behind Escherichia coli in the number of synthetic networks that have been described. While the eukaryotic nature of yeast means that its regulation is not as simple to predict as it is for E. coli, once initial considerations have been made yeast is pleasingly tractable. In this review we provide a loose guide for constructing and implementing synthetic regulatory networks in S. cerevisiae using examples from previous research to highlight available resources, specific considerations and potential future advances.Construction of synthetic regulatory networks in yeast - Accepted ManuscriptBenjamin A. Blount, Tim Weenink, Tom Ellis10.1016/j.febslet.2012.01.053FEBS Letters (2012)2012-02-03FEBS Letters2012-02-03REVIEWhttp://www.febsletters.org/article/PIIS0014579312000816/abstract?rss=yesHighlights: ► The evolutionary patterns of short pentraxins among rat, mouse, and eight other Murinae species and within five species were analyzed. ► Adaptive selection leads to rapid diversification of short pentraxins in Murinae lineages. ► The adaptively selected amino acids lie in the ligand-binding region and contact region between subunits.Abstract: The short pentraxins C-reactive protein (CRP) and serum amyloid P component (SAP) constitute a group of innate immune receptors that trigger immune activation by detecting molecules of the microbial cell wall. Here, we examined the evolution of short pentraxins in Murinae lineages. By molecular evolutionary analysis, CRP and SAP have been experiencing rapid diversification, driven by adaptive selection. Further, our protein modeling demonstrates that adaptively selected amino acids lie in the ligand-binding region and contact region between subunits. Our findings suggest that rapid diversification of these regions could contribute to the determinants of recognizing specificity and the interaction between subunits.Adaptive diversity of innate immune receptor family short pentraxins in Murinae - Uncorrected ProofYan Li, Judith H. Robins, Jianping Ye, Zhiyong Huang, Qiang Wen, Guojie Zhang10.1016/j.febslet.2012.01.048FEBS Letters (2012)2012-02-01FEBS Letters2012-02-01http://www.febsletters.org/article/PIIS0014579312000828/abstract?rss=yesHighlights: ► This article explores the origin of two distinct rat urinary compositional phenotypes. ► An hypothesis is presented that involves gut microbial metabolism of phenylalanine. ► Specific metabolic conversions and pathways are discussed. ► Possible connections to postulated biomarkers for autism are highlighted.Abstract: A novel explanation is proposed for the metabolic differences underlying two distinct rat urinary compositional phenotypes i.e. that these may arise from differences in the gut microbially-mediated metabolism of phenylalanine. As part of this hypothesis, it is further suggested that elements of the mammalian gut microbiota may convert phenylalanine to cinnamic acid, either by means of an ammonia lyase-type reaction or by means of a three step route via phenylpyruvate and phenyllactate. The wider significance of such conversions is discussed with similar metabolism of tryptophan and subsequent glycine conjugation potentially explaining the origin of trans-indolylacryloylglycine, a postulated marker for autism.Metabolic differences underlying two distinct rat urinary phenotypes, a putative role for gut microbial metabolism of phenylalanine and a possible connection to autism - Uncorrected ProofT. Andrew Clayton10.1016/j.febslet.2012.01.049FEBS Letters (2012)2012-02-01FEBS Letters2012-02-01HYPOTHESIShttp://www.febsletters.org/article/PIIS001457931200083X/abstract?rss=yesHighlights: ► Overexpression of miR-203 inhibits laryngeal cancer cell proliferation. ► Survivin is a direct target of miR-203 in laryngeal cancer cells. ► Survivin plays a critical role in miR-203-induced G1 phase cell cycle arrest. ► Survivin mRNA inversely correlates with miR-203 in human laryngeal carcinoma.Abstract: Previous studies have shown that miR-203 acts as a tumor-suppressive microRNA in various cancers, but its roles in laryngeal carcinoma are still contradicted. Here, we found that miR-203 inhibited the growth of laryngeal cancer cells and survivin was a direct target of miR-203. Moreover, silencing of survivin recapitulated the effect of miR-203 on cell cycle progression, whereas overexpression of survivin reversed this effect. Additionally, qRT-PCR showed the reciprocal relationship between miR-203 and survivin in laryngeal cancer tissues. These findings indicate that miR-203 inhibits the proliferation of laryngeal carcinoma cells by directly targeting survivin, suggesting its application in anti-cancer therapeutics.MicroRNA-203 leads to G1 phase cell cycle arrest in laryngeal carcinoma cells by directly targeting survivin - Uncorrected ProofKa Bian, Jing Fan, Xiang Zhang, Xin-Wei Yang, Hua-Yu Zhu, Lei Wang, Jian-Yong Sun, Yan-Ling Meng, Peng-Cheng Cui, Shi-Yin Cheng, Jian Zhang, Jing Zhao, An-Gang Yang, Rui Zhang10.1016/j.febslet.2012.01.050FEBS Letters (2012)2012-02-01FEBS Letters2012-02-01http://www.febsletters.org/article/PIIS0014579312000841/abstract?rss=yesAbstract: Cripto is a small, GPI-anchored signaling protein that regulates cellular survival, proliferation, differentiation and migration during normal developmental processes and tumorigenesis. Cripto functions as an obligatory co-receptor for the TGF-β ligands Nodal, GDF1 and GDF3 but attenuates signaling of others such as activin-A, activin-B and TGF-β1. Soluble, secreted forms of Cripto also activate Src, ras/raf/MAPK and PI3K/Akt pathways via a mechanism that remains largely obscure. This review describes the biological roles and signaling mechanisms of Cripto, highlighting our identification of glucose regulated protein 78 (GRP78) as a cell surface receptor/co-factor required for Cripto signaling via both TGF-β and Src/MAPK/PI3K pathways. We discuss emerging evidence indicating that Cripto/GRP78 signaling regulates normal somatic stem cells and their tumorigenic counterparts.Cripto/GRP78 modulation of the TGF-β pathway in development and oncogenesis - Uncorrected ProofPeter C. Gray, Wylie Vale10.1016/j.febslet.2012.01.051FEBS Letters (2012)2012-02-01FEBS Letters2012-02-01REVIEWhttp://www.febsletters.org/article/PIIS0014579312000786/abstract?rss=yesHighlights: ► We have identified minimal Kaiso constructs for high-affinity DNA binding. ► All three Kaiso zinc fingers are required for binding. ► Extension of the sequence at the N-terminus increases stability of the protein. ► Extension of the sequence at the C-terminus augments DNA affinity.Abstract: Kaiso is a Cys2His2 zinc finger (ZF) protein that mediates methyl-CpG-dependent and sequence-specific transcriptional repression. As a first step towards elucidating the structural and molecular basis for recognition of these disparate DNA sequences, the minimal binding region of Kaiso was identified and optimal DNA sequences for high-affinity interactions were characterized. Contrary to previous findings, Kaiso requires all three zinc fingers plus adjacent protein regions for DNA recognition. An N-terminal extension contributes to structural stability, while an extended C-terminal region augments DNA binding. Complexes formed between the optimized Kaiso construct and both DNA sequences are suitable for future structural evaluation.Kaiso uses all three zinc fingers and adjacent sequence motifs for high affinity binding to sequence-specific and methyl-CpG DNA targets - Uncorrected ProofBethany A. Buck-Koehntop, Maria A. Martinez-Yamout, H. Jane Dyson, Peter E. Wright10.1016/j.febslet.2012.01.045FEBS Letters (2012)2012-01-31FEBS Letters2012-01-31http://www.febsletters.org/article/PIIS0014579312000804/abstract?rss=yesAbstract: HBHA is a cell-surface protein implicated in the dissemination of Mycobacterium tuberculosis from the site of primary infection. Its N-terminal coiled-coil region is also involved in bacterial agglutination. However, despite the importance of HBHA dimerization in agglutination, protein regions involved in dimerization are hitherto not known. Here, we mapped these regions by coupling peptide synthesis, biochemical and computational analyses, and identified structural determinants for HBHA monomer-monomer recognition. Importantly, we obtained the first molecule able to induce HBHA dimer disaggregation at 37°C, the typical growth temperature of Mtb. This result provides new opportunities towards the development of Mtb anti-aggregation molecules with therapeutic interest.Structured summary of protein interactions: HBHA and HBHA bind by molecular sieving (View interaction)HBHA and H1 peptide bind by competition binding (View Interaction)HBHA and H1ext peptide bind by competition binding (View Interaction)HBHA and H2ext peptide bind by competition binding (View Interaction)HBHA and H2 peptide bind by competition binding (View Interaction)HBHA and H2ext peptide bind by competition binding (View Interaction)HBHA and HBHA bind by blue native page (View interaction)Mapping key interactions in the dimerization process of HBHA from Mycobacterium tuberculosis, insights into bacterial agglutination - Accepted ManuscriptCarla Esposito, Marco Cantisani, Gabriella D’Auria, Lucia Falcigno, Emilia Pedone, Stefania Galdiero, Rita Berisio10.1016/j.febslet.2012.01.047FEBS Letters (2012)2012-01-31FEBS Letters2012-01-31http://www.febsletters.org/article/PIIS0014579312000579/abstract?rss=yesHighlights: ► A bipartite archaeal tRNA 2-selenouridine synthase (SelU) was identified in silico. ► Both proteins are required to catalyze tRNA selenation in vivo and in vitro. ► SelU presumably was present in the last common ancestor of bacteria and archaea.Abstract: 5-Methylaminomethyl-2-selenouridine (mnm5Se2U) is found in the first position of the anticodon in certain tRNAs from bacteria, archaea and eukaryotes. This selenonucleoside is formed in Escherichia coli from the corresponding thionucleoside mnm5S2U by the monomeric enzyme YbbB. This nucleoside is present in the tRNA of Methanococcales, yet the corresponding 2-selenouridine synthase is unknown in archaea and eukaryotes. Here we report that a bipartite ybbB ortholog is present in all members of the Methanococcales. Gene deletions in Methanococcus maripaludis and in vitro activity assays confirm that the two proteins act in trans to form in tRNA a selenonucleoside, presumably mnm5Se2U. Phylogenetic data suggest a primal origin of seleno-modified tRNAs.Selenomodification of tRNA in archaea requires a bipartite rhodanese enzyme - Uncorrected ProofDan Su, Temitope T. Ojo, Dieter Söll, Michael J. Hohn10.1016/j.febslet.2012.01.024FEBS Letters (2012)2012-01-30FEBS Letters2012-01-30http://www.febsletters.org/article/PIIS0014579312000646/abstract?rss=yesHighlights: ► MIG-13 is crucial for anterior neural cell migration in Caenorhabditis elegans. ► A mutation in the unc-71 gene rescues the migration defects in mig-13 mutants. ► The unc-71 mutation also rescues the migration defects in src-1 mutants. ► MIG-13 controls anterior cell migration by interacting with UNC-71 and SRC-1.Abstract: The transmembrane protein MIG-13 is a key regulator required for anterior migration of neural cells in Caenorhabditis elegans, but the signaling mechanisms involved remain unknown. Here, we isolated a suppressor mutation in the unc-71/adm-1 gene, which rescued the AVM neuron migration defect in mig-13 mutants. Genetic analyses revealed that UNC-71 at least partly acts downstream of MIG-13 and has an inhibitory effect on the anterior cell migration. The unc-71 mutation also rescued the anterior migration defect of AVM neuron in src-1 mutants. These findings suggest that MIG-13 controls anteroposterior cell migration by interacting with UNC-71 and SRC-1 in C. elegans.MIG-13 controls anteroposterior cell migration by interacting with UNC-71/ADM-1 and SRC-1 in Caenorhabditis elegans - Accepted ManuscriptHitomi Masuda, Kuniaki Nakamura, Nozomu Takata, Bunsho Itoh, Takashi Hirose, Hiroki Moribe, Eisuke Mekada, Masato Okada10.1016/j.febslet.2012.01.031FEBS Letters (2012)2012-01-30FEBS Letters2012-01-30http://www.febsletters.org/article/PIIS0014579312000713/abstract?rss=yesHighlights: ► We create an OIT3 null mouse model. ► Lower serum uric acid level in OIT3 null mice could be due to increase of uric acid excretion. ► Excretion of THP in urine increases while renal THP decreases in OIT3 null mice. ► OIT3 could maintain urate homeostasis by regulating the excretion and reabsorption of uric acid in renal tubule.Abstract: The oncoprotein induced transcript 3 (OIT3), also named liver-specific zona pellucida domain-containing protein (LZP), has been shown to be expressed in kidney, and was confirmed to interact with the Tamm–Horsfall glycoprotein (THP). However, the function of OIT3 in kidney remains unclear. In this study we found that serum uric acid level of Oit3 null mice was significantly lower than that in wild type controls, whereas the excretion of uric acid in urine increased in the mutant mouse. Significantly, the excretion of THP in urine also increased while renal THP decreased in Oit3 null mice. Our data suggest that OIT3 could maintain urate homeostasis by regulating the excretion and reabsorption of uric acid in renal tubule via cooperating with THP.OIT3 deficiency impairs uric acid reabsorption in renal tubule - Uncorrected ProofBing Yan, Zhuang-Zhuang Zhang, Li-Yu Huang, Hai-Lian Shen, Ze-Guang Han10.1016/j.febslet.2012.01.038FEBS Letters (2012)2012-01-30FEBS Letters2012-01-30http://www.febsletters.org/article/PIIS0014579312000725/abstract?rss=yesAbstract: Hepatitis B X-interacting protein (HBXIP) is able to enhance migration of breast cancer cells. However, the role of HBXIP in regulation of complement-dependent cytotoxicity (CDC) in breast cancer is not understood. Here, we report that HBXIP contributes to protecting breast cancer cells from CDC by upregulating membrane-bound complement regulatory protein (mCRPs), including CD46, CD55 and CD59. We found that HBXIP upregulated mCRPs through activating p-ERK1/2/NF-κB. Interestingly, the knockdown of CD59 was able to block the HBXIP-enhanced breast tumor growth in animal. Thus, we conclude that HBXIP upregulates CD46, CD55 and CD59 through p-ERK1/2/NF-κB signaling to protect breast cancer from CDC.HBXIP upregulates CD46, CD55 and CD59 through ERK1/2/NF-κB signaling to protect breast cancer cells from complement attack - Uncorrected ProofWenjing Cui, Yu Zhao, Changliang Shan, Guangyao Kong, Nan Hu, Yiwen Zhang, Shuai Zhang, Weiying Zhang, Yingyi Zhang, Xiaodong Zhang, Lihong Ye10.1016/j.febslet.2012.01.039FEBS Letters (2012)2012-01-30FEBS Letters2012-01-30http://www.febsletters.org/article/PIIS0014579312000737/abstract?rss=yesAbstract: Transforming growth factor-β (TGF-β) and bone morphogenetic protein (BMP) cytokines participate in a multiplicity of ways in the regulation of numerous physiological and pathological processes. Their wide-ranging biological functions are controlled by several mechanisms, including regulation of transcription, complex formation among the signaling receptors (oligomerization) and with co-receptors, binding of the receptors to scaffolding proteins or their targeting to specific membrane domains. Here, we address the generation of TGF-β and BMP receptor homo- and hetero-oligomers and its roles as a mechanism capable of fast regulation of signaling by these crucial cytokines. We examine the available biochemical, biophysical and structural evidence for the ternary structure of these complexes, and the possible roles of homomeric and heteromeric receptor oligomers in signaling.Oligomeric interactions of TGF-β and BMP receptors - Uncorrected ProofMarcelo Ehrlich, Orit Gutman, Petra Knaus, Yoav I. Henis10.1016/j.febslet.2012.01.040FEBS Letters (2012)2012-01-30FEBS Letters2012-01-30REVIEWhttp://www.febsletters.org/article/PIIS0014579312000749/abstract?rss=yesAbstract: microRNAs (miRNAs) are small non-coding RNAs conserved in metazoans. Depletion of miRNAs results in embryonic lethality, suggesting they are essential for embryogenesis. Similarly, pathways induced by growth factors of the transforming growth factor β (TGF-β) superfamily control cell growth, differentiation, and development. Recently Smad proteins, the signal transducers of the TGF-β pathway, were found to regulate miRNA expression, which, in turn, affects expression of numerous proteins. Smads modulate miRNA expression through both transcriptional and post-transcriptional mechanisms illustrating the complexity of gene regulation by TGF-β. In this chapter we summarize the current knowledge of mechanisms underlying Smad-mediated regulation of miRNA biogenesis.Smad-mediated regulation of microRNA biosynthesis - Uncorrected ProofMatthew T. Blahna, Akiko Hata10.1016/j.febslet.2012.01.041FEBS Letters (2012)2012-01-30FEBS Letters2012-01-30REVIEWhttp://www.febsletters.org/article/PIIS0014579312000750/abstract?rss=yesHighlights: ► We replace an ROS-sensitive Cys residue in elongation factor G (EF-G) by Ser. ► Expression of mutated EF-G in a cyanobacterium protects PSII from photoinhibition. ► The protection against photoinhibition is due to the enhanced repair of PSII. ► The enhanced repair is due to the acceleration of protein synthesis.Abstract: The repair of photosystem II (PSII) after photodamage is particularly sensitive to oxidative stress and inhibition of such repair is associated with the oxidation of specific cysteine residues in elongation factor G (EF-G), a key translation factor, in the cyanobacterium Synechocystis sp. PCC 6803. Expression of mutated EF-G with a target cysteine residue replaced by serine in Synechocystis resulted in the protection of PSII from photoinhibition. This protection was attributable to the enhanced repair of PSII via acceleration of the synthesis of the D1 protein, which might have been due to reduced sensitivity of protein synthesis to oxidative stress.A change in the sensitivity of elongation factor G to oxidation protects photosystem II from photoinhibition in Synechocystis sp. PCC 6803 - Uncorrected ProofKayoko Ejima, Tomoko Kawaharada, Shuhei Inoue, Kouji Kojima, Yoshitaka Nishiyama10.1016/j.febslet.2012.01.042FEBS Letters (2012)2012-01-30FEBS Letters2012-01-30http://www.febsletters.org/article/PIIS0014579312000762/abstract?rss=yesHighlights: ► We constructed fusions of the vasopressin V2 receptor with the photoconvertible mKikGR protein. ► We show that mKikGR fusions can be used to study receptor trafficking. ► Using mKikGR fusions, we show that pharmacological chaperones may act co- and post-translationally.Abstract: In this study we demonstrate that the photoconvertible monomeric Kikume green–red (mKikGR) protein is suitable to study trafficking of G protein-coupled receptors. Taking mKikGR-tagged mutants of the vasopressin V2 receptor (V2R) as models, we analyzed whether the V2R-specific pharmacological chaperone SR121463B influences receptor folding on a co- or post-translational level. Misfolded mKikGR-tagged V2Rs were completely photoconverted in the early secretory pathway yielding a red receptor population (already synthesized receptors) and an arising green receptor population (newly synthesized receptors). Trafficking of both receptor populations could be rescued by treatment with SR121463B demonstrating that the substance can act co- and post-translationally.Use of Kikume green–red fusions to study the influence of pharmacological chaperones on trafficking of G protein-coupled receptors - Uncorrected ProofIngrid Ridelis, Antje Schmidt, Anke Teichmann, Jens Furkert, Burkhard Wiesner, Ralf Schülein10.1016/j.febslet.2012.01.043FEBS Letters (2012)2012-01-30FEBS Letters2012-01-30http://www.febsletters.org/article/PIIS0014579312000324/abstract?rss=yesAbstractCharacteristic differences of prions may account for the conformational diversity of the pathogenic isoform of prion protein (PrPSc). Here, we applied a protein detection procedure by using fluorescent-labeled peptides for detecting PrPSc. Five prion protein (PrP) related peptides were found to change significantly their fluorescent intensities with prion-affected animal samples. Their reactivity was different among atypical L-BSE, classical BSE and scrapie. The pull-down assay revealed that they precipitated PrPSc specifically. These findings suggest that fluorescent intensity changes depend on peptide-PrPSc binding. This novel approach may distinguish the fine structural differences in PrPSc, which were not detected by the pull-down assay.Novel assay with fluorescence-labeled PrP peptides for differentiating L-type atypical and classical BSEs, and scrapie - Accepted ManuscriptKazuo Kasai, Akiyoshi Hitara, Takafumi Ohyama, Kiyoshi Nokihara, Takashi Yokoyama, Shirou Mohri10.1016/j.febslet.2012.01.012FEBS Letters (2012)2012-01-27FEBS Letters2012-01-27http://www.febsletters.org/article/PIIS0014579312000361/abstract?rss=yesHighlights: ► LY294002 and wortmannin have opposite functions on LPS- and poly(I:C)-induced IFN-β production. ► LY294002 inhibits LPS- and poly(I:C)-induced IFN-β transcription and secretion in a PI3K-independent manner. ► LY294002 inhibits TLR-induced IFN-β production through inhibition of IRF3 activation and IRF3 DNA binding.Abstract: TLR3 and TLR4 utilize adaptor TRIF to activate IRF3, resulting in IFN-β production to mediate anti-viral infection. In this report, we analyzed the effect of two known PI3K inhibitors LY294002 and wortmannin on LPS- and poly(I:C)-induced IFN-β production in peritoneal macrophages. LY294002 inhibited LPS- and poly(I:C)-induced IFN-β transcription and secretion. In contrast, wortmannin could not inhibit IFN-β production. Furthermore, IRF3 transcriptional activation and binding to IFN-β promoter were found to be inhibited by LY294002. Therefore, our findings demonstrate LY294002 negatively regulates LPS- and poly(I:C)-induced IFN-β production through inhibition of IRF3 activation in a PI3K-independent manner.LY294002 inhibits TLR3/4-mediated IFN-β production via inhibition of IRF3 activation with a PI3K-independent mechanism - Accepted ManuscriptWei Zhao, Jianni Qi, Lijuan Wang, Meng Zhang, Peng Wang, Chengjiang Gao10.1016/j.febslet.2012.01.016FEBS Letters (2012)2012-01-27FEBS Letters2012-01-27http://www.febsletters.org/article/PIIS001457931200052X/abstract?rss=yesHighlights: ► How can destabilizing mutations of lens γ-crystallin cause cataract? ► Cataract-causing mutations stabilize an unfolding intermediate of γD-crystallin. ► Cataract-causing mutants of γD-crystallin are not efficiently bound by α-crystallin. ► Cataract-causing γD-crystallins escape quality control by α-crystallin.Abstract: To test the hypothesis that α-crystallin chaperone activity plays a central role in maintenance of lens transparency, we investigated its interactions with γ-crystallin mutants that cause congenital cataract in mouse models. Although the two substitutions, I4F and V76D, stabilize a partially unfolded γD-crystallin intermediate, their affinities to α-crystallin are marginal even at relatively high concentrations. Detectable binding required further reduction of γD-crystallin stability which was achieved by combining the two mutations. Our results demonstrate that mutants and possibly age-damaged γ-crystallin can escape quality control by lens chaperones rationalizing the observation that they nucleate protein aggregation and lead to cataract.Structured summary of protein interactions: gammaD Crystallin and alphaB Crystallin bind by molecular sieving (View interaction)gammaD Crystallin and alphaB Crystallin bind by fluorescence technology (View interaction)gammaD Crystallin and alphaA Crystallin bind by fluorescence technology (View interaction)gammaD Crystallin and alphaA Crystallin bind by molecular sieving (View interaction)Cataract-linked γD-crystallin mutants have weak affinity to lens chaperones α-crystallins - Uncorrected ProofSanjay Mishra, Richard A. Stein, Hassane S. Mchaourab10.1016/j.febslet.2012.01.019FEBS Letters (2012)2012-01-27FEBS Letters2012-01-27http://www.febsletters.org/article/PIIS0014579312000592/abstract?rss=yesHighlights: ► RUVBL2 transcriptionally represses ARF expression. ► RUVBL2 binds to the distal region of ARF promoter. ► RUVBL2 down-regulates p53 in an ARF-dependent manner.Abstract: ARF is the second most commonly inactivated tumor suppressor behind p53. It has been implicated in the control of cell proliferation, cell senescence, and tumor suppression. However, the detailed mechanism underlying the transcriptional control of ARF remains largely unknown. Here we report RUVBL2 as a novel transcriptional repressor of ARF. Ectopic expression of RUVBL2 decreases the levels of ARF, whereas knockdown of RUVBL2 results in a marked increase in ARF levels. In addition, RUVBL2 down-regulates the levels of p53 in an ARF-dependent manner. Mechanistically, RUVBL2 binds to the distal region of ARF promoter, thus leading to the repression of ARF transcription. These results suggest an important role of RUVBL2 in the regulation of ARF-p53 pathway.RUVBL2 is a novel repressor of ARF transcription - Uncorrected ProofChongwei Xie, Wenyu Wang, Fan Yang, Mian Wu, Yide Mei10.1016/j.febslet.2012.01.026FEBS Letters (2012)2012-01-27FEBS Letters2012-01-27http://www.febsletters.org/article/PIIS0014579312000609/abstract?rss=yesHighlights: ► miR-195 is down-regulated in bladder cancer tissue samples. ► miR-195 inhibits bladder cancer cell T24 growth both in vitro and in vivo. ► miR-195 could induce T24 cell cycle arrest by suppressing CDK4. ► CDK4 is a direct target of miR-195.Abstract: miRNAs are a class of small-noncoding RNAs capable of negatively regulating gene expression. Here, we found that miR-195 is down-regulated in human bladder cancer tissue versus normal adjacent tissue. To better characterize the role of miR-195 in bladder cancer, we conducted gain of function analysis by transfecting bladder cancer cell line T24 with chemically synthesized miR-195 mimic. We identified CDK4, an early G1 cell cycle regulator, as a novel target of miR-195. Selective over-expression of miR-195 could induce G1-phase arrest in T24 cells, and subsequently inhibit T24 cell growth. These findings indicate that miR-195 could be a potential tumor suppressor in bladder cancer.Cyclin-dependent kinase 4 is a novel target in micoRNA-195-mediated cell cycle arrest in bladder cancer cells - Corrected ProofYiwei Lin, Jian Wu, Hong Chen, Yeqing Mao, Yunfu Liu, Qiqi Mao, Kai Yang, Xiangyi Zheng, Liping Xie10.1016/j.febslet.2012.01.027FEBS Letters (2012)2012-01-27FEBS Letters2012-01-27http://www.febsletters.org/article/PIIS0014579312000610/abstract?rss=yesHighlights: ► We revealed that Bach1 has a novel function beyond transcriptional regulation. ► Bach1 functions to maintain mitotic chromosome alignment. ► The exclusion of Bach1 from mitotic chromosome is required for the activity. ► Crm1-mediated regulation is involved in this process. ► DNA binding activity of Bach1 is dispensable for the activity.Abstract: The transcriptional repressor Bach1 mediates various stress responses. Despite its role in transcription, Bach1 is predominantly exported to the cytoplasm in a Crm1-dependent manner, but the functional role of its cytoplasmic retention is still unclear. We found that Bach1 was also excluded from mitotic chromatin by a C-terminal cytoplasmic localization sequence dependent and leptomycin B sensitive process. Bach1 depletion resulted in disordered mitotic chromosome alignment, which was rescued by Bach1 mutants lacking the BTB or DNA binding domains, suggesting its transcription-independent mechanism. We thus revealed a novel role of Bach1 in the regulation of mitotic chromosome dynamics.Transcription-independent role of Bach1 in mitosis through a nuclear exporter Crm1-dependent mechanism - Corrected ProofJie Li, Takuma Shiraki, Kazuhiko Igarashi10.1016/j.febslet.2012.01.028FEBS Letters (2012)2012-01-27FEBS Letters2012-01-27http://www.febsletters.org/article/PIIS0014579312000622/abstract?rss=yesHighlights: ► N-Acetyl lysyl-tRNA synthetases were evolved by a CcdB-based selection. ► N-Acetyl lysine specificity was validated by both in vitro and in vivo approaches. ► Kinetic properties of the evolved synthetases were evaluated for the first time. ► The evolved synthetases will facilitate the systematic study of protein acetylation.Abstract: Posttranslational modifications play a crucial role in modulating protein structure and function. Genetic incorporation of unnatural amino acids into a specific site of a protein facilitates the systematic study of protein modifications including acetylation. We here report the directed evolution of pyrrolysyl-tRNA synthetase (PylRS) from Methanosarcina mazei to create N-acetyl lysyl-tRNA synthetases (AcKRSs) using a new selection system based on the killing activity of the toxic ccdB gene product. The amino acid specificity of these and of published AckRSs was tested in vitro and in vivo, and the enzyme-kinetic properties of the AckRSs were evaluated for the first time.N-Acetyl lysyl-tRNA synthetases evolved by a CcdB-based selection possess N-acetyl lysine specificity in vitro and in vivo - Accepted ManuscriptTakuya Umehara, Jihyo Kim, Sangsik Lee, Li-Tao Guo, Dieter Söll, Hee-Sung Park10.1016/j.febslet.2012.01.029FEBS Letters (2012)2012-01-27FEBS Letters2012-01-27http://www.febsletters.org/article/PIIS0014579312000634/abstract?rss=yesHighlights: ► The monomer–homodimer equilibrium of Hxk2 is affected by serine-15 phosphorylation. ► High-resolution clear-native PAGE is appropriate for phosphohexokinase detection. ► Protein kinase single-deletion mutants were screened for Hxk2 phosphorylation. ► Ymr291W/Tda1 is indispensably required for serine-15 phosphorylation of Hxk2.Abstract: Hxk2 is the predominant hexokinase of Saccharomyces cerevisiae during growth on glucose. In addition to its role in glycolysis, the enzyme is involved in glucose sensing and regulation of gene expression. Glucose limitation causes the phosphorylation of Hxk2 at serine-15 which affects the nucleo-cytoplasmic distribution and dimer stability of the enzyme. In order to identify the responsible kinase, we screened selected protein kinase single-gene deletion mutants by high resolution clear native PAGE. Deletion of YMR291W/TDA1 resulted in the absence of the Hxk2 phosphomonomer, indicating an indispensable role of the corresponding protein in Hxk2 phosphorylation.Saccharomyces cerevisiae gene YMR291W/TDA1 mediates the in vivo phosphorylation of hexokinase isoenzyme 2 at serine-15 - Accepted ManuscriptKarina Kettner, Udo Krause, Sophie Mosler, Claudia Bodenstein, Thomas Kriegel, Gerhard Rödel10.1016/j.febslet.2012.01.030FEBS Letters (2012)2012-01-27FEBS Letters2012-01-27http://www.febsletters.org/article/PIIS0014579312000658/abstract?rss=yesHighlights: ► Bordetella pertussis produce outer membrane vesicles (OMV) that contain biologically active adenylate cyclase toxin (ACT). ► OMV–ACT enter host cells by a mechanism distinct from soluble ACT. ► B. pertussis produce OMV in vivo during the course of a natural human pertussis infection.Abstract: Bordetella pertussis adenylate cyclase toxin (ACT) intoxicates cells by producing intracellular cAMP. B. pertussis outer membrane vesicles (OMV) contain ACT on their surface (OMV–ACT), but the properties of OMV–ACT were previously unknown. We found that B. pertussis in the lung from a fatal pertussis case contains OMV, suggesting an involvement in pathogenesis. OMV–ACT and ACT intoxicate cells with and without the toxin’s receptor CD11b/CD18. Intoxication by ACT is blocked by antitoxin and anti-CD11b antibodies, but not by cytochalasin-D; in contrast, OMV–ACT is unaffected by either antibody and blocked by cytochalasin-D. Thus OMV–ACT can deliver ACT by processes distinct from those of ACT alone.Delivery of Bordetella pertussis adenylate cyclase toxin to target cells via outer membrane vesicles - Uncorrected ProofGina M. Donato, Cynthia S. Goldsmith, Christopher D. Paddock, Joshua C. Eby, Mary C. Gray, Erik L. Hewlett10.1016/j.febslet.2012.01.032FEBS Letters (2012)2012-01-27FEBS Letters2012-01-27http://www.febsletters.org/article/PIIS001457931200066X/abstract?rss=yesHighlights: ► Gβ1 can replace AroQT in the T-protein. ► AroQT/TyrA specific-contact interface is not important to maintain a functional T-protein. ► Gβ1N-terminal β-hairpin residues are important to maintain Gβ1-TyrA expression. ► Gβ1-TyrA expression tolerates substitutions at the C-terminal β-hairpin of the Gβ1 domain. ► The different Gβ1-TyrA protein variants fold in a dimeric conformation.Abstract: T-protein is composed of chorismate mutase (AroQT) fused to the N-terminus of prephenate dehydrogenase (TyrA). Here, we report the replacement of AroQT with the β1-domain of protein G (Gβ1). The TyrA domain shows a strong dehydrogenase activity within the context of this fusion, and our data indicate that Gβ1-TyrA folds into a dimeric conformation. Amino acid substitutions in the Gβ1 domain of Gβ1-TyrA identified residues involved in stabilizing the TyrA dimeric conformation. Gβ1 substitutions in the N-terminal β-hairpin eliminated Gβ1-TyrA expression, whereas Gβ1-TyrA tolerated Gβ1 substitutions in the C-terminal β-hairpin and in the α-helix. All of the characterized variants folded into a dimeric conformation. The importance of the β2-strand in forming a Gβ1 homo-dimerization interface explains the relevance of the first-β-hairpin in stabilizing the dimeric TyrA protein.The β1 domain of protein G can replace the chorismate mutase domain of the T-protein - Uncorrected ProofJoel Osuna, Humberto Flores, Gloria Saab-Rincón10.1016/j.febslet.2012.01.033FEBS Letters (2012)2012-01-27FEBS Letters2012-01-27http://www.febsletters.org/article/PIIS0014579312000671/abstract?rss=yesHighlights: ► Cleavage of Scythe/BAT3 by caspase-3 correlates with its translocation to the cytosol. ► Cytosolic Scythe is required for phosphatidylserine exposure in Fas-triggered cells. ► Cleavage of Scythe in the nucleus is a putative marker for caspase-dependent apoptosis.Abstract: Scythe is a nuclear protein that has been implicated in the apoptotic process in Drosophila melanogaster; however, its role in apoptosis of mammalian cells is not fully elucidated. Here we show that cleavage of Scythe by caspase-3 occurs after activation of both the extrinsic (i.e. Fas/APO-1-mediated) and the intrinsic (i.e. staurosporine-induced) apoptosis pathway. Moreover, this caspase-dependent cleavage correlates with Scythe translocation from the nucleus to the cytosol. We also show that cytosolic re-localization of Scythe is required for Fas/APO-1-triggered phosphatidylserine (PS) exposure, a signal for macrophage clearance of apoptotic cells. Our data suggest that Scythe cleavage may represent a marker for caspase-3 activation and implicate cytosolic re-localization of Scythe in the pathway of PS exposure.Scythe cleavage during Fas (APO-1)-and staurosporine-mediated apoptosis - Uncorrected ProofGiulio Preta, Bengt Fadeel10.1016/j.febslet.2012.01.034FEBS Letters (2012)2012-01-27FEBS Letters2012-01-27http://www.febsletters.org/article/PIIS0014579312000683/abstract?rss=yesHighlights: ► lalA is a paralog of the cyanobacterial clock-related gene labA. ► lalA overexpression reduced amplitude of circadian kaiBC expression. ► lalA overexpression advanced phases of circadian kaiA and psbAI expression. ► lalA overexpression affected cellular growth and viability.Abstract: In the cyanobacterium Synechococcus elongatus, LabA negatively regulates circadian gene expression under the control of Kai-protein-based clock. Here we conducted a molecular genetic analysis of lalA, a paralog of labA. Although a lalA loss of function mutant did not exhibit any apparent phenotype under our experimental conditions, lalA overexpression inhibited cell growth and decreased cell viability. Moderate lalA overexpression brought about abnormalities in circadian gene expression: reduced amplitude of kaiBC expression rhythm, and altered peak and trough timing of psbAI and kaiA expression rhythms. These results imply that lalA is capable of affecting circadian gene expression and cell growth.Overexpression of lalA, a paralog of labA, is capable of affecting both circadian gene expression and cell growth in the cyanobacterium Synechococcus elongatus PCC 7942 - Accepted ManuscriptYasuhito Taniguchi, Tomoe Nishikawa, Takao Kondo, Tokitaka Oyama10.1016/j.febslet.2012.01.035FEBS Letters (2012)2012-01-27FEBS Letters2012-01-27http://www.febsletters.org/article/PIIS0014579312000695/abstract?rss=yesAbstract: In the yeast Saccharomyces cerevisiae, a working model for nutrient homeostasis in eukaryotes, inorganic phosphate (Pi) homeostasis is regulated by the PHO pathway, a set of phosphate starvation induced genes, acting to optimize Pi uptake and utilization. Among these, a subset of proteins containing the SPX domain has been shown to be key regulators of Pi homeostasis. In this review, we summarize the recent progresses in elucidating the mechanisms controlling Pi homeostasis in yeast, focusing on the key roles of the SPX domain-containing proteins in these processes, as well as describing the future challenges and opportunities in this fast-moving field.Phosphate homeostasis in the yeast Saccharomyces cerevisiae, the key role of the SPX domain-containing proteins - Corrected ProofDavid Secco, Chuang Wang, Huixia Shou, James Whelan10.1016/j.febslet.2012.01.036FEBS Letters (2012)2012-01-27FEBS Letters2012-01-27REVIEWhttp://www.febsletters.org/article/PIIS0014579312000701/abstract?rss=yesHighlights: ► First structural characterization of a protein from the DUF269 family. ► Dali search indicates protein fold is unique in current protein space. ► Homodimer with each unit containing 8 α-helices and 3-strand anti-parallel β-sheet. ► Hydrophobic interactions between intermolecular β-sheets hold dimer together. ► Cleft containing conserved charged residues at dimer interface is possible active site.Abstract: The crystal structure for cce_0566 (171 aa, 19.4kDa), a DUF269 annotated protein from the diazotrophic cyanobacterium Cyanothece sp. ATCC 51142, was determined to 1.60Å resolution. cce_0566 is a homodimer with each molecule composed of eight a-helices folded on one side of a three strand anti-parallel β-sheet. Hydrophobic interactions between the side chains of largely conserved residues on the surface of each β-sheet hold the dimer together. The fold observed for cce_0566 may be unique to proteins in the DUF269 family, hence, the protein may also have a function unique to nitrogen fixation. A solvent accessible cleft containing conserved charged residues near the dimer interface could represent the active site or ligand-binding surface for the protein’s biological function.Structured summary of protein interactions: DUF269 and DUF269 bind by x-ray crystallography (View interaction)Crystal structure of cce_0566 from Cyanothece 51142, a protein associated with nitrogen fixation in the DUF269 family - Uncorrected ProofGarry W. Buchko, Howard Robinson10.1016/j.febslet.2012.01.037FEBS Letters (2012)2012-01-27FEBS Letters2012-01-27http://www.febsletters.org/article/PIIS0014579312000269/abstract?rss=yesHighlights: ► MIZ1 is a previously uncharacterized protein encoded by a gene essential for root hydrotropism. ► GFP-tagged MIZ1 is associated with the endoplasmic reticulum membrane (ER) at the cytosolic side.Abstract: MIZ1 is encoded by a gene essential for root hydrotropism in Arabidopsis. To characterize the property of MIZ1, we used transgenic plants expressing GFP-tagged MIZ1 (MIZ1-GFP) and mutant MIZ1 (MIZ1G235E-GFP) in a miz1-1 mutant. Although both chimeric genes were transcribed, the translational products of MIZ1G235E-GFP did not accumulate in roots. Moreover, MIZ1-GFP complemented the mutant phenotype but not MIZ1G235E-GFP. The signal corresponding to MIZ1-GFP was detected at high levels in cortical cells and lateral root cap cells and accumulated in compartments in cortical cells. MIZ1-GFP was fractionated into a soluble protein fraction and an endoplasmic reticulum (ER) membrane fraction, where it was bound to the surface of the ER membrane at the cytosolic side.MIZ1, an essential protein for root hydrotropism, is associated with the cytoplasmic face of the endoplasmic reticulum membrane in Arabidopsis root cells - Uncorrected ProofTomokazu Yamazaki, Yutaka Miyazawa, Akie Kobayashi, Teppei Moriwaki, Nobuharu Fujii, Hideyuki Takahashi10.1016/j.febslet.2012.01.008FEBS Letters (2012)2012-01-25FEBS Letters2012-01-25http://www.febsletters.org/article/PIIS0014579312000373/abstract?rss=yesAbstract: Peptide natural products continue to play an important role in modern medicine as last-resort treatments of many life-threatening diseases, as they display many interesting biological activities ranging from antibiotic to antineoplastic. A large fraction of these microbial natural products is assembled by ribosome-independent mechanisms. Progress in sequencing technology and the mechanistic understanding of secondary metabolite pathways has led to the discovery of many formerly cryptic natural products and a molecular understanding of their assembly. Those advances enable us to apply protein and metabolic engineering approaches towards the manipulation of biosynthetic pathways. In this review we discuss the application potential of both templated and non-templated pathways as well as chemoenzymatic strategies for the structural diversification and tailoring of peptide natural products.Ribosome-independent biosynthesis of biologically active peptides: Application of synthetic biology to generate structural diversity - Corrected ProofTobias W. Giessen, Mohamed A. Marahiel10.1016/j.febslet.2012.01.017FEBS Letters (2012)2012-01-23FEBS Letters2012-01-23REVIEWhttp://www.febsletters.org/article/PIIS0014579312000531/abstract?rss=yesHighlights: ► The binary structure of HpCAD complex NADP(H) is solved at 2.18Å. ► An unusual conformation of the 2′phosphate group of the NADPH, not seen in other CAD structures, was found. ► Docking calculations showed that the substrate is stacked between the aromatic side chains of Tyr116 and Phe114.Abstract: Cinnamyl alcohol dehydrogenase is a zinc- and NADPH-dependent dehydrogenase catalyzing the reversible conversion of p-hydroxycinnamaldehydes to their corresponding hydroxycinnamyl alcohols. A CAD homolog from Helicobacter pylori (HpCAD) possesses broad substrate specificities like the plant CADs and additionally a dismutation activity converting benzaldehyde to benzyl alcohol and benzoic acid. We have determined the crystal structure of HpCAD complexed with NADP(H) at 2.18Å resolution to get a better understanding of this class of CAD outside of plants. The structure of HpCAD is highly homologous to the sinapyl alcohol dehydrogenase and the plant CAD with well-conserved residues involved in catalysis and zinc binding. However, the NADP(H) binding mode of the HpCAD has been found to be significantly different from those of plant CADs.Structured summary of protein interactions: HpCAD and HpCAD bind by x-ray crystallography (View interaction)Unusual NADPH conformation in the crystal structure of a cinnamyl alcohol dehydrogenase from Helicobacter pylori in complex with NADP(H) and substrate docking analysis - Corrected ProofKyung Hye Seo, Ningning Zhuang, Cong Chen, Jae-Young Song, Hyung-Lyun Kang, Kwang-Ho Rhee, Kon Ho Lee10.1016/j.febslet.2012.01.020FEBS Letters (2012)2012-01-23FEBS Letters2012-01-23http://www.febsletters.org/article/PIIS0014579312000543/abstract?rss=yesHighlights: ► A mitochondrial KATP channel (mKATP) is central to ischemic preconditioning (IPC). ► A Kir family member is thought to form the mKATP. ► C. elegans benefit from IPC and display mKATP activity. ► Kir genes in worms are not required for IPC or mKATP.Abstract: Hypoxic preconditioning (HP) is an evolutionarily-conserved mechanism that protects an organism against stress. The mitochondrial ATP-sensitive K+ channel (mKATP) plays an essential role in the protective signaling, but remains molecularly undefined. Several lines of evidence suggest that mKATP may arise from an inward rectifying K+ channel (Kir). The genetic model organism Caenorhabditis elegans exhibits HP and displays mKATP activity. Here, we investigate the tissue expression profile of the three C. elegans Kir genes and demonstrate that mutant strains where the irk genes have been deleted either individually or in combination can be protected by HP and exhibit robust mKATP channel activity in purified mitochondria. These data suggest that the mKATP in C. elegans does not arise from a Kir derived channel.Mitochondrial ATP-sensitive potassium channel activity and hypoxic preconditioning are independent of an inwardly rectifying potassium channel subunit in Caenorhabditis elegans - Corrected ProofAndrew P. Wojtovich, Peter DiStefano, Teresa Sherman, Paul S. Brookes, Keith Nehrke10.1016/j.febslet.2012.01.021FEBS Letters (2012)2012-01-23FEBS Letters2012-01-23http://www.febsletters.org/article/PIIS0014579312000555/abstract?rss=yesHighlights: ► Quantum chemical calculations indicate that even refined phenols like chromanol may be suboptimal antioxidants. ► Aromatic amine (NH) analogues of two chromanols, tocopherol and trolox, were synthesized and evaluated. ► NH-toc and NH-trox were found to be distinctly more potent antioxidants than their phenolic counterparts. ► The evolutionary fixation of tocopherol as primary chain-breaking antioxidant may reflect an event of metabolic coevolution.Abstract: Tocopherol is believed to be the most potent naturally occurring chain-breaking antioxidant. Hence, its refined phenolic head group chromanol may represent an optimum evolutionary solution to the problem of free-radical chain reactions in the lipid bilayer. To test the universal validity of this assumption beyond phenolic head groups, we have synthesized aromatic amine analogues of vitamin E and trolox with otherwise closely matching physicochemical properties: NH-toc and NH-trox. We have found that NH-toc and NH-trox were significantly more potent free radical scavengers, lipid peroxidation inhibitors and cytoprotective agents than their phenolic templates, tocopherol and trolox. In a chemical sense, thus, the chromanol head group does not constitute a global optimum for the design of chain-breaking antioxidants.Is the chromanol head group of vitamin E nature’s final truth on chain-breaking antioxidants? - Uncorrected ProofMaike J. Ohlow, Matthias Granold, Mathias Schreckenberger, Bernd Moosmann10.1016/j.febslet.2012.01.022FEBS Letters (2012)2012-01-23FEBS Letters2012-01-23http://www.febsletters.org/article/PIIS0014579312000567/abstract?rss=yesHighlights: ► The crystal structure of the MU2 FHA domain reveals a dimer. ► The FHA dimer interface is different between MU2 and MDC1. ► The phosphothreonine-binding pocket of MU2 FHA is degenerate. ► MU2 dimerization is constitutive and lacks phosphorylation-mediated regulation.Abstract: Mutator 2 (MU2) in Drosophila melanogaster has been proposed to be the ortholog of human MDC1, a key mediator in DNA damage response. The forkhead-associated (FHA) domain of MDC1 is a dimerization module regulated by trans binding to phosphothreonine 4 from another molecule. Here we present the crystal structure of the MU2 FHA domain at 1.9Å resolution, revealing its evolutionarily conserved role in dimerization. As compared to the MDC1 FHA domain, the MU2 FHA domain dimerizes using a different and more stable interface and contains a degenerate phosphothreonine-binding pocket. Our results suggest that the MU2 dimerization is constitutive and lacks phosphorylation-mediated regulation.Structured summary of protein interactions: MU2 and MU2 bind by cosedimentation in solution (View interaction)MU2 and MU2 bind by X-ray crystallography (View interaction)MU2 and MU2 bind by molecular sieving (View interaction)Dimerization, but not phosphothreonine binding, is conserved between the forkhead-associated domains of Drosophila MU2 and human MDC1 - Corrected ProofShukun Luo, Keqiong Ye10.1016/j.febslet.2012.01.023FEBS Letters (2012)2012-01-23FEBS Letters2012-01-23http://www.febsletters.org/article/PIIS0014579312000300/abstract?rss=yesHighlights: ► This is the first report to clarify how FRP acts in immunity on a molecular level. ► FRP associates with CD14 on the cell surface and triggers TLR4 signaling. ► FRP is considered to be a DAMP, because FRP is one of the endogenous TLR4 agonists. ► Similar to LPS, FRP can induce tolerance to TLR4 signaling in target cells.Abstract: Follistatin-related protein (FRP)/follistatin-like 1 (FSTL1) has multi-specific binding nature especially with TGF-β superfamily proteins, and thereby modulates organ development. However, its function in immune systems remains unclear. Previously, we reported FRP interacts with CD14, which is known to mediate toll-like receptor 4 (TLR4) signaling. Here, we investigated whether FRP activates TLR4 signaling. Recombinant FRP induced interleukin 6 or interleukin 8 production from target cells in a CD14- and TLR4-dependent manner. Moreover, similar to lipopolysaccharide (LPS), FRP induced tolerance to the second LPS stimulation. FRP has the function of evoking innate immune responses as one of the endogenous TLR4 agonists.Structured summary of protein interactions:: FRP physically interacts with CD14 by fluorescence-activated cell sorting (View interaction)Follistatin-related protein/follistatin-like 1 evokes an innate immune response via CD14 and toll-like receptor 4 - Corrected ProofKosaku Murakami, Masao Tanaka, Takashi Usui, Daisuke Kawabata, Aoi Shiomi, Mikiko Iguchi-Hashimoto, Masakazu Shimizu, Naoichiro Yukawa, Hajime Yoshifuji, Takaki Nojima, Koichiro Ohmura, Takao Fujii, Hisanori Umehara, Tsuneyo Mimori10.1016/j.febslet.2012.01.010FEBS Letters (2012)2012-01-18FEBS Letters2012-01-18http://www.febsletters.org/article/PIIS0014579312000312/abstract?rss=yesHighlights: ► We examine physiological relevance of the known crystal structures of Hsp33. ► Interdomain contact site in the inactive monomer is validated in solution. ► Domain-swapped fold of the active dimer is not practical in solution. ► Conformational change in the linker domain is involved in the protein activation.Abstract: Upon dimerization by oxidation, Hsp33 functions as a molecular chaperone in prokaryotes. Previously published structures of both the inactive and active species are of doubtful relevance to the solution conformations since the inactive (reduced) crystal structure was dimeric, while the active (oxidized) species was crystallized with a truncation of its regulation domain. The interdomain contact site of the inactive monomer, identified in this work, is consistent with that previously observed in the reduced dimer crystal. In contrast, fluorescence quenching of the active dimer contradicted the results expected from the domain-swapped fold observed in the truncated dimer crystal. The results of this study provide important new information concerning controversial issues in the activation process of Hsp33.Verification of the interdomain contact site in the inactive monomer, and the domain-swapped fold in the active dimer of Hsp33 in solution - Corrected ProofYoo-Sup Lee, Kyoung-Seok Ryu, Seo-Jin Kim, Hyun-Suk Ko, Dae-Won Sim, Young Ho Jeon, Eun-Hee Kim, Wahn-Soo Choi, Hyung-Sik Won10.1016/j.febslet.2012.01.011FEBS Letters (2012)2012-01-18FEBS Letters2012-01-18http://www.febsletters.org/article/PIIS0014579312000336/abstract?rss=yesHighlights: ► Super-resolution single-particle tracking of immune receptors. ► FcεRI receptors maintain lateral mobility inside receptor clusters. ► FcεRI receptor immobilization is not required for signaling. ► Monte Carlo calculations distinguish biological from statistical variability.Abstract: When mast cells contact a monovalent antigen-bearing fluid lipid bilayer, IgE-loaded FcεRI receptors aggregate at contact points and trigger degranulation and the release of immune activators. We used two-color total internal reflection fluorescence microscopy and single-particle tracking to show that most fluorescently labeled receptor complexes diffuse freely within these micron-size clusters, with a diffusion coefficient comparable to free receptors in resting cells. At later times, when the small clusters coalesce to form larger patches, receptors diffuse even more rapidly. In all cases, Monte Carlo diffusion simulations ensured that the tracking results were free of bias, and distinguished biological from statistical variation. These results show the diversity in receptor mobility in mast cells, demonstrating at least three distinct states of receptor diffusivity.Single-particle tracking of immunoglobulin E receptors (FcεRI) in micron-sized clusters and receptor patches - Corrected ProofKathrin Spendier, Keith A. Lidke, Diane S. Lidke, James L. Thomas10.1016/j.febslet.2012.01.013FEBS Letters (2012)2012-01-18FEBS Letters2012-01-18http://www.febsletters.org/article/PIIS0014579312000348/abstract?rss=yesHighlights: ► Introducing the notion of chemical synthetic biology. ► Highlight the use of lipid vesicles as cell models. ► The laboratory construction of synthetic minimal cell for basic and applied research. ► Never Born Proteins (totally random proteins): description and experimental results. ► Never Born RNAs (random RNAs): description and experimental results.Abstract: Synthetic biology is first represented in terms of two complementary aspects, the bio-engineering one, based on the genetic manipulation of extant microbial forms in order to obtain forms of life which do not exist in nature; and the chemical synthetic biology, an approach mostly based on chemical manipulation for the laboratory synthesis of biological structures that do not exist in nature. The paper is mostly devoted to shortly review chemical synthetic biology projects currently carried out in our laboratory. In particular, we describe: the minimal cell project, then the “Never Born Proteins” and lastly the Never Born RNAs. We describe and critically analyze the main results, emphasizing the possible relevance of chemical synthetic biology for the progress in basic science and biotechnology.Approaches to chemical synthetic biology - Corrected ProofCristiano Chiarabelli, Pasquale Stano, Fabrizio Anella, Paolo Carrara, Pier Luigi Luisi10.1016/j.febslet.2012.01.014FEBS Letters (2012)2012-01-18FEBS Letters2012-01-18REVIEWhttp://www.febsletters.org/article/PIIS001457931200035X/abstract?rss=yesHighlights: ► We explore the role of miR-18a in pancreatic progenitor and acinar cells. ► We find that miR-18a targets Ptf1a 3′UTR to decrease its protein and mRNA levels. ► MiR-18a regulates pancreatic progenitor and acinar cells in a fine-tuning way.Abstract: The basic helix–loop–helix (bHLH) transcription factor Ptf1a plays stage-specific roles in the developing pancreas. During early pancreatic development, low levels of Ptf1a preferentially promote the differentiation of pancreatic progenitor cells into endocrine cells, whereas high levels of Ptf1a shift pancreatic progenitors towards an exocrine cell fate. In adults, Ptf1a is essential for the production of exocrine enzymes by pancreatic acinar cells. In this paper, we show that Ptf1a expression is repressed by miR-18a in pancreatic progenitors and acinar cells via its binding to the 3′UTR of Ptf1a mRNA. Furthermore, overexpression of miR-18a exerts little effect on pancreatic progenitors and acinar cells. These results indicate that miR-18a plays a fine-tuning role in regulating pancreatic progenitors and exocrine cells through the repression of Ptf1a expression.MiR-18a regulates expression of the pancreatic transcription factor Ptf1a in pancreatic progenitor and acinar cells - Corrected ProofYankun Yang, Lei Ding, Yang An, Zhen-wu Zhang, Yanhe Lang, Sheng Tai, Fangqi Guo, Chun-Bo Teng10.1016/j.febslet.2012.01.015FEBS Letters (2012)2012-01-18FEBS Letters2012-01-18http://www.febsletters.org/article/PIIS0014579312000385/abstract?rss=yesHighlights: ► Isoform co-expression in various tissues necessitates differential regulation. ► Conserved point mutations in single domain paralogs with similar core functions. ► Data mining indicates differential phosphorylation of vertebrate paralogs occurs. ► Paralog specific phosphosites exist in cofilins and profilins. ► Mapping phosphosites on 3D structures explains effects of differential regulation.Abstract: Evolutionary conservation for structure function relations is commonly accepted. Here we hypothesize that closely related single domain paralogous proteins, having similar expression profiles and redundant biochemical core functions, additionally evolved to allow and maintain isoform specific differential regulation by single conserved amino acid substitutions. To substantiate this, we considered two families of closely related actin binding proteins combined with data mining of phosphorylated residues in human and mouse proteins. We show that such residues are identical in other orthologs whereas paralogs have a different, but also conserved, non-phosphorylatable residue at the equivalent positions.Phosphosite conservation in single domain orthologs versus paralogs: A way to combine differential regulation with redundant core functions - Corrected ProofLynn Huyck, Marleen Van Troys, Christophe Ampe10.1016/j.febslet.2012.01.018FEBS Letters (2012)2012-01-18FEBS Letters2012-01-18HYPOTHESIShttp://www.febsletters.org/article/PIIS0014579312000233/abstract?rss=yesHighlights: ► Synaptotagmin-II of rat and mouse acts as neuronal high affinity receptor for BoNT/B and G. ► Mutation F54L converts rat synaptotagmin-II to a low affinity receptor of BoNT/B and G. ► F54 corresponds to L51 in human synaptoagmin-II. ► Human synaptotagmin-II is not a high affinity receptor for BoNT/B and G due to L51.Abstract: Botulinum neurotoxins (BoNTs) inhibit neurotransmitter release by hydrolysing SNARE proteins essential for exocytosis. The synaptic vesicle protein synaptotagmin-II of rat and mouse acts as neuronal high affinity receptor for BoNT/B and BoNT/G. Here, we show that human synaptotagmin-II is not a high affinity receptor for BoNT/B and G due to a phenylalanine to leucine mutation in its luminal domain present only in humans and chimpanzees. It eliminates one of three major interactions between synaptotagmin-II and BoNT/B and hereby explains the disparity in potency of BoNT/B in humans and mice as well as the 40-fold higher dosage of rimabotulinumtoxinB versus onabotulinumtoxinA.Structured summary of protein interactions: rSyt-II binds to BoNT/G by pull down (View Interaction: 1, 2)rSyt-II binds to BoNT/B by pull down (View Interaction: 1, 2)Human synaptotagmin-II is not a high affinity receptor for botulinum neurotoxin B and G: Increased therapeutic dosage and immunogenicity - Corrected ProofJasmin Strotmeier, Gesche Willjes, Thomas Binz, Andreas Rummel10.1016/j.febslet.2011.12.037FEBS Letters (2012)2012-01-16FEBS Letters2012-01-16http://www.febsletters.org/article/PIIS0014579312000245/abstract?rss=yesHighlights: ► miR-195-5p negatively regulates the expression of GLUT3 through GLUT3 3’UTR. ► miR-195-5p is the first identified microRNA that targets GLUT3. ► Over-expression of miR-195-5p decreases GLUT3-mediated glucose uptake. ► miR-195-5p significantly inhibits cell growth through reducing GLUT3 expression.Abstract: It has been reported that expression of glucose transporter member 3 (GLUT3) is up-regulated in bladder cancers. However, the regulating mechanism remains unknown. Here, we assessed whether microRNAs (miRNAs) regulate GLUT3 expression in bladder cancers. In our study, miR-195-5p was identified to directly targeted GLUT3 3′-untranslated region (UTR) in bladder cancer T24 cells. Small interfering RNA (siRNA)- and miR-195-5p-mediated GLUT3 knockdown experiments revealed that miR-195-5p decreased T24 cells glucose uptake, inhibited cell growth and promoted cell apoptosis through suppression of GLUT3 expression. Therefore, miR-195-5p is a novel and also the first identified miRNA that targets GLUT3, and the aberrant decreased expression of miR-195-5p and consequent GLUT3 up-regulation may contribute to bladder carcinogenesis.MicroRNA-195-5p suppresses glucose uptake and proliferation of human bladder cancer T24 cells by regulating GLUT3 expression - Corrected ProofXiang Fei, Manlong Qi, Bin Wu, Yongsheng Song, Yueping Wang, Tingting Li10.1016/j.febslet.2012.01.006FEBS Letters (2012)2012-01-16FEBS Letters2012-01-16