ALBERT

Description: Variable regions 1 and 2 (V1/V2) of human immunodeficiency virus-1 (HIV-1) gp120 envelope glycoprotein are critical for viral evasion of antibody neutralization, and are themselves protected by extraordinary sequence diversity and N-linked glycosylation. Human antibodies such as PG9 nonetheless engage V1/V2 and neutralize 80% of HIV-1 isolates. Here we report the structure of V1/V2 in complex with PG9. V1/V2 forms a four-stranded beta-sheet domain, in which sequence diversity and glycosylation are largely segregated to strand-connecting loops. PG9 recognition involves electrostatic, sequence-independent and glycan interactions: the latter account for over half the interactive surface but are of sufficiently weak affinity to avoid autoreactivity. The structures of V1/V2-directed antibodies CH04 and PGT145 indicate that they share a common mode of glycan penetration by extended anionic loops. In addition to structurally defining V1/V2, the results thus identify a paradigm of antibody recognition for highly glycosylated antigens, which-with PG9-involves a site of vulnerability comprising just two glycans and a strand.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3406929/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3406929/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉McLellan, Jason S -- Pancera, Marie -- Carrico, Chris -- Gorman, Jason -- Julien, Jean-Philippe -- Khayat, Reza -- Louder, Robert -- Pejchal, Robert -- Sastry, Mallika -- Dai, Kaifan -- O'Dell, Sijy -- Patel, Nikita -- Shahzad-ul-Hussan, Syed -- Yang, Yongping -- Zhang, Baoshan -- Zhou, Tongqing -- Zhu, Jiang -- Boyington, Jeffrey C -- Chuang, Gwo-Yu -- Diwanji, Devan -- Georgiev, Ivelin -- Kwon, Young Do -- Lee, Doyung -- Louder, Mark K -- Moquin, Stephanie -- Schmidt, Stephen D -- Yang, Zhi-Yong -- Bonsignori, Mattia -- Crump, John A -- Kapiga, Saidi H -- Sam, Noel E -- Haynes, Barton F -- Burton, Dennis R -- Koff, Wayne C -- Walker, Laura M -- Phogat, Sanjay -- Wyatt, Richard -- Orwenyo, Jared -- Wang, Lai-Xi -- Arthos, James -- Bewley, Carole A -- Mascola, John R -- Nabel, Gary J -- Schief, William R -- Ward, Andrew B -- Wilson, Ian A -- Kwong, Peter D -- R01 AI033292/AI/NIAID NIH HHS/ -- R01 AI084817/AI/NIAID NIH HHS/ -- RR017573/RR/NCRR NIH HHS/ -- Canadian Institutes of Health Research/Canada -- Intramural NIH HHS/ -- England -- Nature. 2011 Nov 23;480(7377):336-43. doi: 10.1038/nature10696.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22113616" target="_blank"〉PubMed〈/a〉

Description: G-protein-coupled receptors (GPCRs) signal primarily through G proteins or arrestins. Arrestin binding to GPCRs blocks G protein interaction and redirects signalling to numerous G-protein-independent pathways. Here we report the crystal structure of a constitutively active form of human rhodopsin bound to a pre-activated form of the mouse visual arrestin, determined by serial femtosecond X-ray laser crystallography. Together with extensive biochemical and mutagenesis data, the structure reveals an overall architecture of the rhodopsin-arrestin assembly in which rhodopsin uses distinct structural elements, including transmembrane helix 7 and helix 8, to recruit arrestin. Correspondingly, arrestin adopts the pre-activated conformation, with a approximately 20 degrees rotation between the amino and carboxy domains, which opens up a cleft in arrestin to accommodate a short helix formed by the second intracellular loop of rhodopsin. This structure provides a basis for understanding GPCR-mediated arrestin-biased signalling and demonstrates the power of X-ray lasers for advancing the frontiers of structural biology.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4521999/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4521999/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kang, Yanyong -- Zhou, X Edward -- Gao, Xiang -- He, Yuanzheng -- Liu, Wei -- Ishchenko, Andrii -- Barty, Anton -- White, Thomas A -- Yefanov, Oleksandr -- Han, Gye Won -- Xu, Qingping -- de Waal, Parker W -- Ke, Jiyuan -- Tan, M H Eileen -- Zhang, Chenghai -- Moeller, Arne -- West, Graham M -- Pascal, Bruce D -- Van Eps, Ned -- Caro, Lydia N -- Vishnivetskiy, Sergey A -- Lee, Regina J -- Suino-Powell, Kelly M -- Gu, Xin -- Pal, Kuntal -- Ma, Jinming -- Zhi, Xiaoyong -- Boutet, Sebastien -- Williams, Garth J -- Messerschmidt, Marc -- Gati, Cornelius -- Zatsepin, Nadia A -- Wang, Dingjie -- James, Daniel -- Basu, Shibom -- Roy-Chowdhury, Shatabdi -- Conrad, Chelsie E -- Coe, Jesse -- Liu, Haiguang -- Lisova, Stella -- Kupitz, Christopher -- Grotjohann, Ingo -- Fromme, Raimund -- Jiang, Yi -- Tan, Minjia -- Yang, Huaiyu -- Li, Jun -- Wang, Meitian -- Zheng, Zhong -- Li, Dianfan -- Howe, Nicole -- Zhao, Yingming -- Standfuss, Jorg -- Diederichs, Kay -- Dong, Yuhui -- Potter, Clinton S -- Carragher, Bridget -- Caffrey, Martin -- Jiang, Hualiang -- Chapman, Henry N -- Spence, John C H -- Fromme, Petra -- Weierstall, Uwe -- Ernst, Oliver P -- Katritch, Vsevolod -- Gurevich, Vsevolod V -- Griffin, Patrick R -- Hubbell, Wayne L -- Stevens, Raymond C -- Cherezov, Vadim -- Melcher, Karsten -- Xu, H Eric -- DK071662/DK/NIDDK NIH HHS/ -- EY005216/EY/NEI NIH HHS/ -- EY011500/EY/NEI NIH HHS/ -- GM073197/GM/NIGMS NIH HHS/ -- GM077561/GM/NIGMS NIH HHS/ -- GM095583/GM/NIGMS NIH HHS/ -- GM097463/GM/NIGMS NIH HHS/ -- GM102545/GM/NIGMS NIH HHS/ -- GM103310/GM/NIGMS NIH HHS/ -- GM104212/GM/NIGMS NIH HHS/ -- GM108635/GM/NIGMS NIH HHS/ -- P30EY000331/EY/NEI NIH HHS/ -- P41 GM103310/GM/NIGMS NIH HHS/ -- P41GM103393/GM/NIGMS NIH HHS/ -- P41RR001209/RR/NCRR NIH HHS/ -- P50 GM073197/GM/NIGMS NIH HHS/ -- P50 GM073210/GM/NIGMS NIH HHS/ -- R01 DK066202/DK/NIDDK NIH HHS/ -- R01 DK071662/DK/NIDDK NIH HHS/ -- R01 EY011500/EY/NEI NIH HHS/ -- R01 GM087413/GM/NIGMS NIH HHS/ -- R01 GM109955/GM/NIGMS NIH HHS/ -- S10 RR027270/RR/NCRR NIH HHS/ -- U54 GM094586/GM/NIGMS NIH HHS/ -- U54 GM094599/GM/NIGMS NIH HHS/ -- U54 GM094618/GM/NIGMS NIH HHS/ -- England -- Nature. 2015 Jul 30;523(7562):561-7. doi: 10.1038/nature14656. Epub 2015 Jul 22.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Laboratory of Structural Sciences, Center for Structural Biology and Drug Discovery, Van Andel Research Institute, Grand Rapids, Michigan 49503, USA. ; Department of Chemistry and Biochemistry, and Center for Applied Structural Discovery, Biodesign Institute, Arizona State University, Tempe, Arizona 85287-1604, USA. ; Department of Chemistry, Bridge Institute, University of Southern California, Los Angeles, California 90089, USA. ; Center for Free Electron Laser Science, Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg, Germany. ; Joint Center for Structural Genomics, Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA. ; 1] Laboratory of Structural Sciences, Center for Structural Biology and Drug Discovery, Van Andel Research Institute, Grand Rapids, Michigan 49503, USA [2] Department of Obstetrics &Gynecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore. ; The National Resource for Automated Molecular Microscopy, New York Structural Biology Center, New York, New York 10027, USA. ; Department of Molecular Therapeutics, The Scripps Research Institute, Scripps Florida, Jupiter, Florida 33458, USA. ; Jules Stein Eye Institute and Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, USA. ; Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada. ; Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232, USA. ; Linac Coherent Light Source (LCLS), SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA. ; 1] Linac Coherent Light Source (LCLS), SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA [2] BioXFEL, NSF Science and Technology Center, 700 Ellicott Street, Buffalo, New York 14203, USA. ; 1] Department of Chemistry and Biochemistry, and Center for Applied Structural Discovery, Biodesign Institute, Arizona State University, Tempe, Arizona 85287-1604, USA [2] Department of Physics, Arizona State University, Tempe, Arizona 85287, USA. ; 1] Department of Chemistry and Biochemistry, and Center for Applied Structural Discovery, Biodesign Institute, Arizona State University, Tempe, Arizona 85287-1604, USA [2] Beijing Computational Science Research Center, Haidian District, Beijing 10084, China. ; 1] Department of Chemistry and Biochemistry, and Center for Applied Structural Discovery, Biodesign Institute, Arizona State University, Tempe, Arizona 85287-1604, USA [2] Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53211, USA. ; State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China. ; Department of Obstetrics &Gynecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore. ; Swiss Light Source at Paul Scherrer Institute, CH-5232 Villigen, Switzerland. ; Department of Biological Sciences, Bridge Institute, University of Southern California, Los Angeles, California 90089, USA. ; School of Medicine and School of Biochemistry and Immunology, Trinity College, Dublin 2, Ireland. ; 1] BioXFEL, NSF Science and Technology Center, 700 Ellicott Street, Buffalo, New York 14203, USA [2] Ben May Department for Cancer Research, University of Chicago, Chicago, Illinois 60637, USA. ; Laboratory of Biomolecular Research at Paul Scherrer Institute, CH-5232 Villigen, Switzerland. ; Department of Biology, Universitat Konstanz, 78457 Konstanz, Germany. ; Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China. ; 1] Center for Free Electron Laser Science, Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg, Germany [2] Centre for Ultrafast Imaging, 22761 Hamburg, Germany. ; 1] Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada [2] Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada. ; 1] Department of Chemistry, Bridge Institute, University of Southern California, Los Angeles, California 90089, USA [2] Department of Biological Sciences, Bridge Institute, University of Southern California, Los Angeles, California 90089, USA [3] iHuman Institute, ShanghaiTech University, 2F Building 6, 99 Haike Road, Pudong New District, Shanghai 201210, China. ; 1] Laboratory of Structural Sciences, Center for Structural Biology and Drug Discovery, Van Andel Research Institute, Grand Rapids, Michigan 49503, USA [2] VARI-SIMM Center, Center for Structure and Function of Drug Targets, CAS-Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26200343" target="_blank"〉PubMed〈/a〉

Description: The potential impact of pandemic influenza makes effective measures to limit the spread and morbidity of virus infection a public health priority. Antiviral drugs are seen as essential requirements for control of initial influenza outbreaks caused by a new virus, and in pre-pandemic plans there is a heavy reliance on drug stockpiles. The principal target for these drugs is a virus surface glycoprotein, neuraminidase, which facilitates the release of nascent virus and thus the spread of infection. Oseltamivir (Tamiflu) and zanamivir (Relenza) are two currently used neuraminidase inhibitors that were developed using knowledge of the enzyme structure. It has been proposed that the closer such inhibitors resemble the natural substrate, the less likely they are to select drug-resistant mutant viruses that retain viability. However, there have been reports of drug-resistant mutant selection in vitro and from infected humans. We report here the enzymatic properties and crystal structures of neuraminidase mutants from H5N1-infected patients that explain the molecular basis of resistance. Our results show that these mutants are resistant to oseltamivir but still strongly inhibited by zanamivir owing to an altered hydrophobic pocket in the active site of the enzyme required for oseltamivir binding. Together with recent reports of the viability and pathogenesis of H5N1 (ref. 7) and H1N1 (ref. 8) viruses with neuraminidases carrying these mutations, our results indicate that it would be prudent for pandemic stockpiles of oseltamivir to be augmented by additional antiviral drugs, including zanamivir.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Collins, Patrick J -- Haire, Lesley F -- Lin, Yi Pu -- Liu, Junfeng -- Russell, Rupert J -- Walker, Philip A -- Skehel, John J -- Martin, Stephen R -- Hay, Alan J -- Gamblin, Steven J -- MC_U117512711/Medical Research Council/United Kingdom -- MC_U117512723/Medical Research Council/United Kingdom -- MC_U117570592/Medical Research Council/United Kingdom -- MC_U117584222/Medical Research Council/United Kingdom -- Medical Research Council/United Kingdom -- England -- Nature. 2008 Jun 26;453(7199):1258-61. doi: 10.1038/nature06956. Epub 2008 May 14.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉MRC-National Institute for Medical Research, Mill Hill, London NW7 1AA, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18480754" target="_blank"〉PubMed〈/a〉

Description: Glucose homeostasis is a vital and complex process, and its disruption can cause hyperglycaemia and type II diabetes mellitus. Glucokinase (GK), a key enzyme that regulates glucose homeostasis, converts glucose to glucose-6-phosphate in pancreatic beta-cells, liver hepatocytes, specific hypothalamic neurons, and gut enterocytes. In hepatocytes, GK regulates glucose uptake and glycogen synthesis, suppresses glucose production, and is subject to the endogenous inhibitor GK regulatory protein (GKRP). During fasting, GKRP binds, inactivates and sequesters GK in the nucleus, which removes GK from the gluconeogenic process and prevents a futile cycle of glucose phosphorylation. Compounds that directly hyperactivate GK (GK activators) lower blood glucose levels and are being evaluated clinically as potential therapeutics for the treatment of type II diabetes mellitus. However, initial reports indicate that an increased risk of hypoglycaemia is associated with some GK activators. To mitigate the risk of hypoglycaemia, we sought to increase GK activity by blocking GKRP. Here we describe the identification of two potent small-molecule GK-GKRP disruptors (AMG-1694 and AMG-3969) that normalized blood glucose levels in several rodent models of diabetes. These compounds potently reversed the inhibitory effect of GKRP on GK activity and promoted GK translocation both in vitro (isolated hepatocytes) and in vivo (liver). A co-crystal structure of full-length human GKRP in complex with AMG-1694 revealed a previously unknown binding pocket in GKRP distinct from that of the phosphofructose-binding site. Furthermore, with AMG-1694 and AMG-3969 (but not GK activators), blood glucose lowering was restricted to diabetic and not normoglycaemic animals. These findings exploit a new cellular mechanism for lowering blood glucose levels with reduced potential for hypoglycaemic risk in patients with type II diabetes mellitus.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lloyd, David J -- St Jean, David J Jr -- Kurzeja, Robert J M -- Wahl, Robert C -- Michelsen, Klaus -- Cupples, Rod -- Chen, Michelle -- Wu, John -- Sivits, Glenn -- Helmering, Joan -- Komorowski, Renee -- Ashton, Kate S -- Pennington, Lewis D -- Fotsch, Christopher -- Vazir, Mukta -- Chen, Kui -- Chmait, Samer -- Zhang, Jiandong -- Liu, Longbin -- Norman, Mark H -- Andrews, Kristin L -- Bartberger, Michael D -- Van, Gwyneth -- Galbreath, Elizabeth J -- Vonderfecht, Steven L -- Wang, Minghan -- Jordan, Steven R -- Veniant, Murielle M -- Hale, Clarence -- England -- Nature. 2013 Dec 19;504(7480):437-40. doi: 10.1038/nature12724. Epub 2013 Nov 13.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Metabolic Disorders, Amgen Inc., One Amgen Center Drive, Thousand Oaks, California 91320, USA. ; Department of Therapeutic Discovery, Amgen Inc., One Amgen Center Drive, Thousand Oaks, California 91320, USA. ; Department of Comparative Biology & Safety Sciences, Amgen Inc., One Amgen Center Drive, Thousand Oaks, California 91320, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24226772" target="_blank"〉PubMed〈/a〉

Description: Cell-surface-receptor binding by influenza viruses is a key determinant of their transmissibility, both from avian and animal species to humans as well as from human to human. Highly pathogenic avian H5N1 viruses that are a threat to public health have been observed to acquire affinity for human receptors, and transmissible-mutant-selection experiments have identified a virus that is transmissible in ferrets, the generally accepted experimental model for influenza in humans. Here, our quantitative biophysical measurements of the receptor-binding properties of haemagglutinin (HA) from the transmissible mutant indicate a small increase in affinity for human receptor and a marked decrease in affinity for avian receptor. From analysis of virus and HA binding data we have derived an algorithm that predicts virus avidity from the affinity of individual HA-receptor interactions. It reveals that the transmissible-mutant virus has a 200-fold preference for binding human over avian receptors. The crystal structure of the transmissible-mutant HA in complex with receptor analogues shows that it has acquired the ability to bind human receptor in the same folded-back conformation as seen for HA from the 1918, 1957 (ref. 4), 1968 (ref. 5) and 2009 (ref. 6) pandemic viruses. This binding mode is substantially different from that by which non-transmissible wild-type H5 virus HA binds human receptor. The structure of the complex also explains how the change in preference from avian to human receptors arises from the Gln226Leu substitution, which facilitates binding to human receptor but restricts binding to avian receptor. Both features probably contribute to the acquisition of transmissibility by this mutant virus.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Xiong, Xiaoli -- Coombs, Peter J -- Martin, Stephen R -- Liu, Junfeng -- Xiao, Haixia -- McCauley, John W -- Locher, Kathrin -- Walker, Philip A -- Collins, Patrick J -- Kawaoka, Yoshihiro -- Skehel, John J -- Gamblin, Steven J -- BB/E010806/Biotechnology and Biological Sciences Research Council/United Kingdom -- MC_U117512723/Medical Research Council/United Kingdom -- MC_U117584222/Medical Research Council/United Kingdom -- U117512723/Medical Research Council/United Kingdom -- U117570592/Medical Research Council/United Kingdom -- U117584222/Medical Research Council/United Kingdom -- England -- Nature. 2013 May 16;497(7449):392-6. doi: 10.1038/nature12144. Epub 2013 Apr 24.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/23615615" target="_blank"〉PubMed〈/a〉

Description: Insulin receptor signalling has a central role in mammalian biology, regulating cellular metabolism, growth, division, differentiation and survival. Insulin resistance contributes to the pathogenesis of type 2 diabetes mellitus and the onset of Alzheimer's disease; aberrant signalling occurs in diverse cancers, exacerbated by cross-talk with the homologous type 1 insulin-like growth factor receptor (IGF1R). Despite more than three decades of investigation, the three-dimensional structure of the insulin-insulin receptor complex has proved elusive, confounded by the complexity of producing the receptor protein. Here we present the first view, to our knowledge, of the interaction of insulin with its primary binding site on the insulin receptor, on the basis of four crystal structures of insulin bound to truncated insulin receptor constructs. The direct interaction of insulin with the first leucine-rich-repeat domain (L1) of insulin receptor is seen to be sparse, the hormone instead engaging the insulin receptor carboxy-terminal alpha-chain (alphaCT) segment, which is itself remodelled on the face of L1 upon insulin binding. Contact between insulin and L1 is restricted to insulin B-chain residues. The alphaCT segment displaces the B-chain C-terminal beta-strand away from the hormone core, revealing the mechanism of a long-proposed conformational switch in insulin upon receptor engagement. This mode of hormone-receptor recognition is novel within the broader family of receptor tyrosine kinases. We support these findings by photo-crosslinking data that place the suggested interactions into the context of the holoreceptor and by isothermal titration calorimetry data that dissect the hormone-insulin receptor interface. Together, our findings provide an explanation for a wealth of biochemical data from the insulin receptor and IGF1R systems relevant to the design of therapeutic insulin analogues.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3793637/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3793637/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Menting, John G -- Whittaker, Jonathan -- Margetts, Mai B -- Whittaker, Linda J -- Kong, Geoffrey K-W -- Smith, Brian J -- Watson, Christopher J -- Zakova, Lenka -- Kletvikova, Emilia -- Jiracek, Jiri -- Chan, Shu Jin -- Steiner, Donald F -- Dodson, Guy G -- Brzozowski, Andrzej M -- Weiss, Michael A -- Ward, Colin W -- Lawrence, Michael C -- DK13914/DK/NIDDK NIH HHS/ -- DK20595/DK/NIDDK NIH HHS/ -- DK40949/DK/NIDDK NIH HHS/ -- R01 DK040949/DK/NIDDK NIH HHS/ -- UL1 TR000439/TR/NCATS NIH HHS/ -- Biotechnology and Biological Sciences Research Council/United Kingdom -- England -- Nature. 2013 Jan 10;493(7431):241-5. doi: 10.1038/nature11781.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/23302862" target="_blank"〉PubMed〈/a〉

Description: A key step in many chromatin-related processes is the recognition of histone post-translational modifications by effector modules such as bromodomains and chromo-like domains of the Royal family. Whereas effector-mediated recognition of single post-translational modifications is well characterized, how the cell achieves combinatorial readout of histones bearing multiple modifications is poorly understood. One mechanism involves multivalent binding by linked effector modules. For example, the tandem bromodomains of human TATA-binding protein-associated factor-1 (TAF1) bind better to a diacetylated histone H4 tail than to monoacetylated tails, a cooperative effect attributed to each bromodomain engaging one acetyl-lysine mark. Here we report a distinct mechanism of combinatorial readout for the mouse TAF1 homologue Brdt, a testis-specific member of the BET protein family. Brdt associates with hyperacetylated histone H4 (ref. 7) and is implicated in the marked chromatin remodelling that follows histone hyperacetylation during spermiogenesis, the stage of spermatogenesis in which post-meiotic germ cells mature into fully differentiated sperm. Notably, we find that a single bromodomain (BD1) of Brdt is responsible for selectively recognizing histone H4 tails bearing two or more acetylation marks. The crystal structure of BD1 bound to a diacetylated H4 tail shows how two acetyl-lysine residues cooperate to interact with one binding pocket. Structure-based mutagenesis that reduces the selectivity of BD1 towards diacetylated tails destabilizes the association of Brdt with acetylated chromatin in vivo. Structural analysis suggests that other chromatin-associated proteins may be capable of a similar mode of ligand recognition, including yeast Bdf1, human TAF1 and human CBP/p300 (also known as CREBBP and EP300, respectively). Our findings describe a new mechanism for the combinatorial readout of histone modifications in which a single effector module engages two marks on a histone tail as a composite binding epitope.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Moriniere, Jeanne -- Rousseaux, Sophie -- Steuerwald, Ulrich -- Soler-Lopez, Montserrat -- Curtet, Sandrine -- Vitte, Anne-Laure -- Govin, Jerome -- Gaucher, Jonathan -- Sadoul, Karin -- Hart, Darren J -- Krijgsveld, Jeroen -- Khochbin, Saadi -- Muller, Christoph W -- Petosa, Carlo -- England -- Nature. 2009 Oct 1;461(7264):664-8. doi: 10.1038/nature08397.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉European Molecular Biology Laboratory, Grenoble Outstation, 6 rue Jules Horowitz, BP 181, 38042 Grenoble Cedex 9, France.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19794495" target="_blank"〉PubMed〈/a〉

Description: The human immunodeficiency virus type 1 (HIV-1) envelope (Env) spike, comprising three gp120 and three gp41 subunits, is a conformational machine that facilitates HIV-1 entry by rearranging from a mature unliganded state, through receptor-bound intermediates, to a post-fusion state. As the sole viral antigen on the HIV-1 virion surface, Env is both the target of neutralizing antibodies and a focus of vaccine efforts. Here we report the structure at 3.5 A resolution for an HIV-1 Env trimer captured in a mature closed state by antibodies PGT122 and 35O22. This structure reveals the pre-fusion conformation of gp41, indicates rearrangements needed for fusion activation, and defines parameters of immune evasion and immune recognition. Pre-fusion gp41 encircles amino- and carboxy-terminal strands of gp120 with four helices that form a membrane-proximal collar, fastened by insertion of a fusion peptide-proximal methionine into a gp41-tryptophan clasp. Spike rearrangements required for entry involve opening the clasp and expelling the termini. N-linked glycosylation and sequence-variable regions cover the pre-fusion closed spike; we used chronic cohorts to map the prevalence and location of effective HIV-1-neutralizing responses, which were distinguished by their recognition of N-linked glycan and tolerance for epitope-sequence variation.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4348022/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4348022/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Pancera, Marie -- Zhou, Tongqing -- Druz, Aliaksandr -- Georgiev, Ivelin S -- Soto, Cinque -- Gorman, Jason -- Huang, Jinghe -- Acharya, Priyamvada -- Chuang, Gwo-Yu -- Ofek, Gilad -- Stewart-Jones, Guillaume B E -- Stuckey, Jonathan -- Bailer, Robert T -- Joyce, M Gordon -- Louder, Mark K -- Tumba, Nancy -- Yang, Yongping -- Zhang, Baoshan -- Cohen, Myron S -- Haynes, Barton F -- Mascola, John R -- Morris, Lynn -- Munro, James B -- Blanchard, Scott C -- Mothes, Walther -- Connors, Mark -- Kwong, Peter D -- AI0678501/AI/NIAID NIH HHS/ -- AI100645/AI/NIAID NIH HHS/ -- P01 GM056550/GM/NIGMS NIH HHS/ -- P01-GM56550/GM/NIGMS NIH HHS/ -- P30 AI050410/AI/NIAID NIH HHS/ -- R01 GM098859/GM/NIGMS NIH HHS/ -- R01-GM098859/GM/NIGMS NIH HHS/ -- R21 AI100696/AI/NIAID NIH HHS/ -- R21-AI100696/AI/NIAID NIH HHS/ -- UL1 TR000142/TR/NCATS NIH HHS/ -- UM1 AI100645/AI/NIAID NIH HHS/ -- ZIA AI005023-13/Intramural NIH HHS/ -- ZIA AI005024-13/Intramural NIH HHS/ -- England -- Nature. 2014 Oct 23;514(7523):455-61. doi: 10.1038/nature13808. Epub 2014 Oct 8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA. ; HIV-Specific Immunity Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA. ; Center for HIV and STIs, National Institute for Communicable Diseases of the National Health Laboratory Service (NHLS), Sandringham, Johannesburg 2131, South Africa. ; Departments of Medicine, Epidemiology, Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. ; Duke University Human Vaccine Institute, Departments of Medicine, Surgery, Pediatrics and Immunology, Duke University School of Medicine, and the Center for HIV/AIDS Vaccine Immunology-Immunogen Discovery at Duke University, Durham, North Carolina 27710, USA. ; 1] Center for HIV and STIs, National Institute for Communicable Diseases of the National Health Laboratory Service (NHLS), Sandringham, Johannesburg 2131, South Africa [2] University of the Witwatersrand, Braamfontein, Johannesburg 2000, South Africa [3] Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban 4041, South Africa. ; Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut 06536, USA. ; Department of Physiology and Biophysics, Weill Cornell Medical College of Cornell University, New York, New York 10021, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25296255" target="_blank"〉PubMed〈/a〉

Description: Pentatricopeptide repeat (PPR) proteins represent a large family of sequence-specific RNA-binding proteins that are involved in multiple aspects of RNA metabolism. PPR proteins, which are found in exceptionally large numbers in the mitochondria and chloroplasts of terrestrial plants, recognize single-stranded RNA (ssRNA) in a modular fashion. The maize chloroplast protein PPR10 binds to two similar RNA sequences from the ATPI-ATPH and PSAJ-RPL33 intergenic regions, referred to as ATPH and PSAJ, respectively. By protecting the target RNA elements from 5' or 3' exonucleases, PPR10 defines the corresponding 5' and 3' messenger RNA termini. Despite rigorous functional characterizations, the structural basis of sequence-specific ssRNA recognition by PPR proteins remains to be elucidated. Here we report the crystal structures of PPR10 in RNA-free and RNA-bound states at resolutions of 2.85 and 2.45 A, respectively. In the absence of RNA binding, the nineteen repeats of PPR10 are assembled into a right-handed superhelical spiral. PPR10 forms an antiparallel, intertwined homodimer and exhibits considerable conformational changes upon binding to its target ssRNA, an 18-nucleotide PSAJ element. Six nucleotides of PSAJ are specifically recognized by six corresponding PPR10 repeats following the predicted code. The molecular basis for the specific and modular recognition of RNA bases A, G and U is revealed. The structural elucidation of RNA recognition by PPR proteins provides an important framework for potential biotechnological applications of PPR proteins in RNA-related research areas.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Yin, Ping -- Li, Quanxiu -- Yan, Chuangye -- Liu, Ying -- Liu, Junjie -- Yu, Feng -- Wang, Zheng -- Long, Jiafu -- He, Jianhua -- Wang, Hong-Wei -- Wang, Jiawei -- Zhu, Jian-Kang -- Shi, Yigong -- Yan, Nieng -- Howard Hughes Medical Institute/ -- England -- Nature. 2013 Dec 5;504(7478):168-71. doi: 10.1038/nature12651. Epub 2013 Oct 27.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] State Key Laboratory of Bio-membrane and Membrane Biotechnology, Tsinghua University, Beijing 100084, China [2] Center for Structural Biology, School of Life Sciences and School of Medicine, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing 100084, China [3].〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24162847" target="_blank"〉PubMed〈/a〉

Description: In the 1950s, the drug thalidomide, administered as a sedative to pregnant women, led to the birth of thousands of children with multiple defects. Despite the teratogenicity of thalidomide and its derivatives lenalidomide and pomalidomide, these immunomodulatory drugs (IMiDs) recently emerged as effective treatments for multiple myeloma and 5q-deletion-associated dysplasia. IMiDs target the E3 ubiquitin ligase CUL4-RBX1-DDB1-CRBN (known as CRL4(CRBN)) and promote the ubiquitination of the IKAROS family transcription factors IKZF1 and IKZF3 by CRL4(CRBN). Here we present crystal structures of the DDB1-CRBN complex bound to thalidomide, lenalidomide and pomalidomide. The structure establishes that CRBN is a substrate receptor within CRL4(CRBN) and enantioselectively binds IMiDs. Using an unbiased screen, we identified the homeobox transcription factor MEIS2 as an endogenous substrate of CRL4(CRBN). Our studies suggest that IMiDs block endogenous substrates (MEIS2) from binding to CRL4(CRBN) while the ligase complex is recruiting IKZF1 or IKZF3 for degradation. This dual activity implies that small molecules can modulate an E3 ubiquitin ligase and thereby upregulate or downregulate the ubiquitination of proteins.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4423819/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4423819/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Fischer, Eric S -- Bohm, Kerstin -- Lydeard, John R -- Yang, Haidi -- Stadler, Michael B -- Cavadini, Simone -- Nagel, Jane -- Serluca, Fabrizio -- Acker, Vincent -- Lingaraju, Gondichatnahalli M -- Tichkule, Ritesh B -- Schebesta, Michael -- Forrester, William C -- Schirle, Markus -- Hassiepen, Ulrich -- Ottl, Johannes -- Hild, Marc -- Beckwith, Rohan E J -- Harper, J Wade -- Jenkins, Jeremy L -- Thoma, Nicolas H -- AG011085/AG/NIA NIH HHS/ -- R01 AG011085/AG/NIA NIH HHS/ -- England -- Nature. 2014 Aug 7;512(7512):49-53. doi: 10.1038/nature13527. Epub 2014 Jul 16.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland [2] University of Basel, Petersplatz 10, CH-4003 Basel, Switzerland. ; Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA. ; Novartis Institutes for Biomedical Research, 250 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA. ; 1] Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland [2] University of Basel, Petersplatz 10, CH-4003 Basel, Switzerland [3] Swiss Institute of Bioinformatics, Maulbeerstrasse 66, CH-4058 Basel, Switzerland. ; Novartis Pharma AG, Institutes for Biomedical Research, Novartis Campus, CH-4056 Basel, Switzerland.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25043012" target="_blank"〉PubMed〈/a〉