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Alshehabi Y, Martin DDO. Protective Proteolysis in Huntington's Disease: Unraveling the Role of Post-Translational Myristoylation of Huntingtin in Autophagy. J Huntingtons Dis 2024:JHD240028. [PMID: 38995796 DOI: 10.3233/jhd-240028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/14/2024]
Abstract
Huntington's disease (HD) is a devastating neurodegenerative disorder characterized by impaired motor function and cognitive decline, ultimately leading to death. HD is caused by a polyglutamine expansion in the N-terminal region of the huntingtin (HTT) protein, which is linked to decreased HTT turnover, increased HTT proteolysis, increased HTT aggregation, and subsequent neuronal death. In this review, we explore the mechanism of the protective effect of blocking HTT proteolysis at D586, which has been shown to rescue the HD phenotype in HD mouse models. Until recently, the mechanism remained unclear. Herein, we discuss how blocking HTT proteolysis at D586 promotes HTT turnover by correcting autophagy, and making HTT a better autophagy substrate, through post-translational myristoylation of HTT at G553.
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Affiliation(s)
- Yasmeen Alshehabi
- NeurdyPhagy Lab, Department of Biology, Faculty of Science, University of Waterloo, Waterloo, ON, Canada
| | - Dale D O Martin
- NeurdyPhagy Lab, Department of Biology, Faculty of Science, University of Waterloo, Waterloo, ON, Canada
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2
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Zhang H, Wu S, Itzhaki LS, Perrett S. Interaction between huntingtin exon 1 and HEAT repeat structure probed by chimeric model proteins. Protein Sci 2023; 32:e4810. [PMID: 37853955 PMCID: PMC10659953 DOI: 10.1002/pro.4810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 10/11/2023] [Accepted: 10/15/2023] [Indexed: 10/20/2023]
Abstract
Huntington disease (HD) is associated with aggregation of huntingtin (HTT) protein containing over 35 continuous Q residues within the N-terminal exon 1 encoded region. The C-terminal of the HTT protein consists mainly of HEAT repeat structure which serves as a scaffold for multiple cellular activities. Structural and biochemical analysis of the intact HTT protein has been hampered by its huge size (~300 kDa) and most in vitro studies to date have focused on the properties of the exon 1 region. To explore the interaction between HTT exon 1 and the HEAT repeat structure, we constructed chimeric proteins containing the N-terminal HTT exon 1 region and the HEAT repeat protein PR65/A. The results indicate that HTT exon 1 slightly destabilizes the downstream HEAT repeat structure and endows the HEAT repeat structure with more conformational flexibility. Wild-type and pathological lengths of polyQ did not show differences in the interaction between HTT exon 1 and the HEAT repeats. With the C-terminal fusion of PR65/A, HTT exon 1 containing pathological lengths of polyQ could still form amyloid fibrils, but the higher-order architecture of fibrils and kinetics of fibril formation were affected by the C-terminal fusion of HEAT repeats. This indicates that interaction between HTT exon 1 and HEAT repeat structure is compatible with both normal function of HTT protein and the pathogenesis of HD, and this study provides a potential model for further exploration.
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Affiliation(s)
- Hong Zhang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in BiomacromoleculesInstitute of Biophysics, Chinese Academy of SciencesBeijingChina
- University of the Chinese Academy of SciencesBeijingChina
- Institute of Basic Medical Sciences, Chinese Academy of Medical SciencesPeking Union Medical CollegeBeijingChina
| | - Si Wu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in BiomacromoleculesInstitute of Biophysics, Chinese Academy of SciencesBeijingChina
- University of the Chinese Academy of SciencesBeijingChina
| | | | - Sarah Perrett
- National Laboratory of Biomacromolecules, CAS Center for Excellence in BiomacromoleculesInstitute of Biophysics, Chinese Academy of SciencesBeijingChina
- University of the Chinese Academy of SciencesBeijingChina
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3
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Jiang A, Handley RR, Lehnert K, Snell RG. From Pathogenesis to Therapeutics: A Review of 150 Years of Huntington's Disease Research. Int J Mol Sci 2023; 24:13021. [PMID: 37629202 PMCID: PMC10455900 DOI: 10.3390/ijms241613021] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 08/15/2023] [Accepted: 08/18/2023] [Indexed: 08/27/2023] Open
Abstract
Huntington's disease (HD) is a debilitating neurodegenerative genetic disorder caused by an expanded polyglutamine-coding (CAG) trinucleotide repeat in the huntingtin (HTT) gene. HD behaves as a highly penetrant dominant disorder likely acting through a toxic gain of function by the mutant huntingtin protein. Widespread cellular degeneration of the medium spiny neurons of the caudate nucleus and putamen are responsible for the onset of symptomology that encompasses motor, cognitive, and behavioural abnormalities. Over the past 150 years of HD research since George Huntington published his description, a plethora of pathogenic mechanisms have been proposed with key themes including excitotoxicity, dopaminergic imbalance, mitochondrial dysfunction, metabolic defects, disruption of proteostasis, transcriptional dysregulation, and neuroinflammation. Despite the identification and characterisation of the causative gene and mutation and significant advances in our understanding of the cellular pathology in recent years, a disease-modifying intervention has not yet been clinically approved. This review includes an overview of Huntington's disease, from its genetic aetiology to clinical presentation and its pathogenic manifestation. An updated view of molecular mechanisms and the latest therapeutic developments will also be discussed.
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Affiliation(s)
- Andrew Jiang
- Applied Translational Genetics Group, Centre for Brain Research, School of Biological Sciences, The University of Auckland, Auckland 1010, New Zealand; (R.R.H.); (K.L.); (R.G.S.)
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4
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Lemarié FL, Sanders SS, Nguyen Y, Martin DDO, Hayden MR. Full-length huntingtin is palmitoylated at multiple sites and post-translationally myristoylated following caspase-cleavage. Front Physiol 2023; 14:1086112. [PMID: 36711022 PMCID: PMC9880554 DOI: 10.3389/fphys.2023.1086112] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 01/02/2023] [Indexed: 01/15/2023] Open
Abstract
Introduction: Huntington disease is an autosomal dominant neurodegenerative disorder which is caused by a CAG repeat expansion in the HTT gene that codes for an elongated polyglutamine tract in the huntingtin (HTT) protein. Huntingtin is subjected to multiple post-translational modifications which regulate its cellular functions and degradation. We have previously identified a palmitoylation site at cysteine 214 (C214), catalyzed by the enzymes ZDHHC17 and ZDHHC13. Reduced palmitoylation level of mutant huntingtin is linked to toxicity and loss of function. Moreover, we have described N-terminal myristoylation by the N-myristoyltransferases of a short fragment of huntingtin (HTT553-586) at glycine 553 (G553) following proteolysis at aspartate 552 (D552). Results: Here, we show that huntingtin is palmitoylated at numerous cysteines: C105, C433, C3134 and C3144. In addition, we confirm that full-length huntingtin is cleaved at D552 and post-translationally myristoylated at G553. Importantly, blocking caspase cleavage at the critical and pathogenic aspartate 586 (D586) significantly increases posttranslational myristoylation of huntingtin. In turn, myristoylation of huntingtin promotes the co-interaction between C-terminal and N-terminal huntingtin fragments, which is also protective. Discussion: This suggests that the protective effect of inhibiting caspase-cleavage at D586 may be mediated through post-translational myristoylation of huntingtin at G553.
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Seefelder M, Klein FAC, Landwehrmeyer B, Fernández-Busnadiego R, Kochanek S. Huntingtin and Its Partner Huntingtin-Associated Protein 40: Structural and Functional Considerations in Health and Disease. J Huntingtons Dis 2022; 11:227-242. [PMID: 35871360 PMCID: PMC9484127 DOI: 10.3233/jhd-220543] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Since the discovery of the mutation causing Huntington’s disease (HD) in 1993, it has been debated whether an expanded polyglutamine (polyQ) stretch affects the properties of the huntingtin (HTT) protein and thus contributes to the pathological mechanisms responsible for HD. Here we review the current knowledge about the structure of HTT, alone (apo-HTT) or in a complex with Huntingtin-Associated Protein 40 (HAP40), the influence of polyQ-length variation on apo-HTT and the HTT-HAP40 complex, and the biology of HAP40. Phylogenetic analyses suggest that HAP40 performs essential functions. Highlighting the relevance of its interaction with HTT, HAP40 is one of the most abundant partners copurifying with HTT and is rapidly degraded, when HTT levels are reduced. As the levels of both proteins decrease during disease progression, HAP40 could also be a biomarker for HD. Whether declining HAP40 levels contribute to disease etiology is an open question. Structural studies have shown that the conformation of apo-HTT is less constrained but resembles that adopted in the HTT-HAP40 complex, which is exceptionally stable because of extensive interactions between HAP40 and the three domains of HTT. The complex— and to some extent apo-HTT— resists fragmentation after limited proteolysis. Unresolved regions of apo-HTT, constituting about 25% of the protein, are the main sites of post-translational modifications and likely have major regulatory functions. PolyQ elongation does not substantially alter the structure of HTT, alone or when associated with HAP40. Particularly, polyQ above the disease length threshold does not induce drastic conformational changes in full-length HTT. Therefore, models of HD pathogenesis stating that polyQ expansion drastically alters HTT properties should be reconsidered.
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Affiliation(s)
| | | | | | - Rubén Fernández-Busnadiego
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany
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6
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Podvin S, Rosenthal SB, Poon W, Wei E, Fisch KM, Hook V. Mutant Huntingtin Protein Interaction Map Implicates Dysregulation of Multiple Cellular Pathways in Neurodegeneration of Huntington's Disease. J Huntingtons Dis 2022; 11:243-267. [PMID: 35871359 PMCID: PMC9484122 DOI: 10.3233/jhd-220538] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Huntington's disease (HD) is a genetic neurodegenerative disease caused by trinucleotide repeat (CAG) expansions in the human HTT gene encoding the huntingtin protein (Htt) with an expanded polyglutamine tract. OBJECTIVE HD models from yeast to transgenic mice have investigated proteins interacting with mutant Htt that may initiate molecular pathways of cell death. There is a paucity of datasets of published Htt protein interactions that include the criteria of 1) defining fragments or full-length Htt forms, 2) indicating the number of poly-glutamines of the mutant and wild-type Htt forms, and 3) evaluating native Htt interaction complexes. This research evaluated such interactor data to gain understanding of Htt dysregulation of cellular pathways. METHODS Htt interacting proteins were compiled from the literature that meet our criteria and were subjected to network analysis via clustering, gene ontology, and KEGG pathways using rigorous statistical methods. RESULTS The compiled data of Htt interactors found that both mutant and wild-type Htt interact with more than 2,971 proteins. Application of a community detection algorithm to all known Htt interactors identified significant signal transduction, membrane trafficking, chromatin, and mitochondrial clusters, among others. Binomial analyses of a subset of reported protein interactor information determined that chromatin organization, signal transduction and endocytosis were diminished, while mitochondria, translation and membrane trafficking had enriched overall edge effects. CONCLUSION The data support the hypothesis that mutant Htt disrupts multiple cellular processes causing toxicity. This dataset is an open resource to aid researchers in formulating hypotheses of HD mechanisms of pathogenesis.
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Affiliation(s)
- Sonia Podvin
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Sara Brin Rosenthal
- Center for Computational Biology & Bioinformatics, University of California, San Diego, La Jolla, CA, USA
| | - William Poon
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Enlin Wei
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Kathleen M Fisch
- Center for Computational Biology & Bioinformatics, University of California, San Diego, La Jolla, CA, USA.,Department of Obstetrics, Gynecology & Reproductive Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Vivian Hook
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, USA.,Department of Neuroscience and Dept of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, CA, USA
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7
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Di Nardo M, Pallotta MM, Musio A. The multifaceted roles of cohesin in cancer. J Exp Clin Cancer Res 2022; 41:96. [PMID: 35287703 PMCID: PMC8919599 DOI: 10.1186/s13046-022-02321-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 03/09/2022] [Indexed: 12/13/2022] Open
Abstract
The cohesin complex controls faithful chromosome segregation by pairing sister chromatids after DNA replication until mitosis. In addition, it is crucial for hierarchal three-dimensional organization of the genome, transcription regulation and maintaining DNA integrity. The core complex subunits SMC1A, SMC3, STAG1/2, and RAD21 as well as its modulators, have been found to be recurrently mutated in human cancers. The mechanisms by which cohesin mutations trigger cancer development and disease progression are still poorly understood. Since cohesin is involved in a range of chromosome-related processes, the outcome of cohesin mutations in cancer is complex. Herein, we discuss recent discoveries regarding cohesin that provide new insight into its role in tumorigenesis.
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Affiliation(s)
- Maddalena Di Nardo
- Institute for Biomedical Technologies (ITB), National Research Council (CNR), Via Moruzzi, 1 56124, Pisa, Italy
| | - Maria M. Pallotta
- Institute for Biomedical Technologies (ITB), National Research Council (CNR), Via Moruzzi, 1 56124, Pisa, Italy
| | - Antonio Musio
- Institute for Biomedical Technologies (ITB), National Research Council (CNR), Via Moruzzi, 1 56124, Pisa, Italy
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8
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Mier P, Paladin L, Tamana S, Petrosian S, Hajdu-Soltész B, Urbanek A, Gruca A, Plewczynski D, Grynberg M, Bernadó P, Gáspári Z, Ouzounis CA, Promponas VJ, Kajava AV, Hancock JM, Tosatto SCE, Dosztanyi Z, Andrade-Navarro MA. Disentangling the complexity of low complexity proteins. Brief Bioinform 2021; 21:458-472. [PMID: 30698641 PMCID: PMC7299295 DOI: 10.1093/bib/bbz007] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 12/19/2018] [Accepted: 01/07/2019] [Indexed: 12/31/2022] Open
Abstract
There are multiple definitions for low complexity regions (LCRs) in protein sequences, with all of them broadly considering LCRs as regions with fewer amino acid types compared to an average composition. Following this view, LCRs can also be defined as regions showing composition bias. In this critical review, we focus on the definition of sequence complexity of LCRs and their connection with structure. We present statistics and methodological approaches that measure low complexity (LC) and related sequence properties. Composition bias is often associated with LC and disorder, but repeats, while compositionally biased, might also induce ordered structures. We illustrate this dichotomy, and more generally the overlaps between different properties related to LCRs, using examples. We argue that statistical measures alone cannot capture all structural aspects of LCRs and recommend the combined usage of a variety of predictive tools and measurements. While the methodologies available to study LCRs are already very advanced, we foresee that a more comprehensive annotation of sequences in the databases will enable the improvement of predictions and a better understanding of the evolution and the connection between structure and function of LCRs. This will require the use of standards for the generation and exchange of data describing all aspects of LCRs. Short abstract There are multiple definitions for low complexity regions (LCRs) in protein sequences. In this critical review, we focus on the definition of sequence complexity of LCRs and their connection with structure. We present statistics and methodological approaches that measure low complexity (LC) and related sequence properties. Composition bias is often associated with LC and disorder, but repeats, while compositionally biased, might also induce ordered structures. We illustrate this dichotomy, plus overlaps between different properties related to LCRs, using examples.
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Affiliation(s)
- Pablo Mier
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Lisanna Paladin
- Department of Biomedical Science, University of Padova, Padova, Italy
| | - Stella Tamana
- Bioinformatics Research Laboratory, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
| | - Sophia Petrosian
- Biological Computation and Process Laboratory, Chemical Process & Energy Resources Institute, Centre for Research & Technology Hellas, Thessalonica, Greece
| | - Borbála Hajdu-Soltész
- MTA-ELTE Lendület Bioinformatics Research Group, Department of Biochemistry, Eötvös Loránd University, Budapest, Hungary
| | - Annika Urbanek
- Centre de Biochimie Structurale, INSERM, CNRS, Université de Montpellier, Montpellier, France
| | - Aleksandra Gruca
- Institute of Informatics, Silesian University of Technology, Gliwice, Poland
| | - Dariusz Plewczynski
- Center of New Technologies, University of Warsaw, Warsaw, Poland.,Faculty of Mathematics and Information Science, Warsaw University of Technology, Warsaw, Poland
| | | | - Pau Bernadó
- Centre de Biochimie Structurale, INSERM, CNRS, Université de Montpellier, Montpellier, France
| | - Zoltán Gáspári
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
| | - Christos A Ouzounis
- Biological Computation and Process Laboratory, Chemical Process & Energy Resources Institute, Centre for Research & Technology Hellas, Thessalonica, Greece
| | - Vasilis J Promponas
- Bioinformatics Research Laboratory, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
| | - Andrey V Kajava
- Centre de Recherche en Biologie Cellulaire de Montpellier, CNRS-UMR, Institut de Biologie Computationnelle, Universite de Montpellier, Montpellier, France.,Institute of Bioengineering, University ITMO, St. Petersburg, Russia
| | - John M Hancock
- Earlham Institute, Norwich, UK.,ELIXIR Hub, Welcome Genome Campus, Hinxton, UK
| | - Silvio C E Tosatto
- Department of Biomedical Science, University of Padova, Padova, Italy.,CNR Institute of Neuroscience, Padova, Italy
| | - Zsuzsanna Dosztanyi
- MTA-ELTE Lendület Bioinformatics Research Group, Department of Biochemistry, Eötvös Loránd University, Budapest, Hungary
| | - Miguel A Andrade-Navarro
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg University of Mainz, Mainz, Germany
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Chongtham A, Bornemann DJ, Barbaro BA, Lukacsovich T, Agrawal N, Syed A, Worthge S, Purcell J, Burke J, Chin TM, Marsh JL. Effects of flanking sequences and cellular context on subcellular behavior and pathology of mutant HTT. Hum Mol Genet 2021; 29:674-688. [PMID: 31943010 DOI: 10.1093/hmg/ddaa001] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 12/06/2019] [Accepted: 01/07/2020] [Indexed: 12/11/2022] Open
Abstract
Huntington's disease (HD) is caused by an expansion of a poly glutamine (polyQ) stretch in the huntingtin protein (HTT) that is necessary to cause pathology and formation of HTT aggregates. Here we ask whether expanded polyQ is sufficient to cause pathology and aggregate formation. By addressing the sufficiency question, one can identify cellular processes and structural parameters that influence HD pathology and HTT subcellular behavior (i.e. aggregation state and subcellular location). Using Drosophila, we compare the effects of expressing mutant full-length human HTT (fl-mHTT) to the effects of mutant human HTTexon1 and to two commonly used synthetic fragments, HTT171 and shortstop (HTT118). Expanded polyQ alone is not sufficient to cause inclusion formation since full-length HTT and HTTex1 with expanded polyQ are both toxic although full-length HTT remains diffuse while HTTex1 forms inclusions. Further, inclusions are not sufficient to cause pathology since HTT171-120Q forms inclusions but is benign and co-expression of HTT171-120Q with non-aggregating pathogenic fl-mHTT recruits fl-mHTT to aggregates and rescues its pathogenicity. Additionally, the influence of sequences outside the expanded polyQ domain is revealed by finding that small modifications to the HTT118 or HTT171 fragments can dramatically alter their subcellular behavior and pathogenicity. Finally, mutant HTT subcellular behavior is strongly modified by different cell and tissue environments (e.g. fl-mHTT appears as diffuse nuclear in one tissue and diffuse cytoplasmic in another but toxic in both). These observations underscore the importance of cellular and structural context for the interpretation and comparison of experiments using different fragments and tissues to report the effects of expanded polyQ.
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Affiliation(s)
- Anjalika Chongtham
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92697-2300, USA.,Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125
| | - Douglas J Bornemann
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92697-2300, USA
| | - Brett A Barbaro
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92697-2300, USA
| | - Tamas Lukacsovich
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92697-2300, USA
| | - Namita Agrawal
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92697-2300, USA
| | - Adeela Syed
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92697-2300, USA
| | - Shane Worthge
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92697-2300, USA
| | - Judith Purcell
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92697-2300, USA
| | - John Burke
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92697-2300, USA
| | - Theodore M Chin
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125
| | - J Lawrence Marsh
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92697-2300, USA
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Brandi V, Polticelli F. In Silico Analysis of Huntingtin Homologs in Lower Eukaryotes. Int J Mol Sci 2021; 22:3214. [PMID: 33809947 PMCID: PMC8004120 DOI: 10.3390/ijms22063214] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 03/09/2021] [Accepted: 03/17/2021] [Indexed: 12/11/2022] Open
Abstract
Huntington's disease is a rare neurodegenerative and autosomal dominant disorder. HD is caused by a mutation in the gene coding for huntingtin (Htt). The result is the production of a mutant Htt with an abnormally long polyglutamine repeat that leads to pathological Htt aggregates. Although the structure of human Htt has been determined, albeit at low resolution, its functions and how they are performed are largely unknown. Moreover, there is little information on the structure and function of Htt in other organisms. The comparison of Htt homologs can help to understand if there is a functional conservation of domains in the evolution of Htt in eukaryotes. In this work, through a computational approach, Htt homologs from lower eukaryotes have been analysed, identifying ordered domains and modelling their structure. Based on the structural models, a putative function for most of the domains has been predicted. A putative C. elegans Htt-like protein has also been analysed following the same approach. The results obtained support the notion that this protein is a orthologue of human Htt.
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Affiliation(s)
| | - Fabio Polticelli
- Department of Sciences, Roma Tre University, 00146 Rome, Italy;
- National Institute of Nuclear Physics, Roma Tre Section, 00146 Rome, Italy
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11
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Kamel M, Kastano K, Mier P, Andrade-Navarro MA. REP2: A Web Server to Detect Common Tandem Repeats in Protein Sequences. J Mol Biol 2021; 433:166895. [PMID: 33972020 DOI: 10.1016/j.jmb.2021.166895] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 02/01/2021] [Accepted: 02/21/2021] [Indexed: 12/13/2022]
Abstract
Ensembles of tandem repeats (TRs) in protein sequences expand rapidly to form domains well suited for interactions with proteins. For this reason, they are relatively frequent. Some TRs have known structures and therefore it is advantageous to predict their presence in a protein sequence. However, since most TRs diverge quickly, their detection by classical sequence comparison algorithms is not very accurate. Previously, we developed a method and a web server that used curated profiles and thresholds for the detection of 11 common TRs. Here we present a new web server (REP2) that allows the analysis of TRs in both individual and aligned sequences. We provide currently precomputed analyses for a selection of 78 UniProt reference proteomes. We illustrate how these data can be used to study the evolution of TRs using comparative genomics. REP2 can be accessed at http://cbdm-01.zdv.uni-mainz.de/~munoz/rep/.
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Affiliation(s)
- Mohamed Kamel
- Department of Computer Science, Faculty of Mathematics and Informatics, University of M'sila, 28000 M'sila, Algeria; Faculty of Biology, Johannes Gutenberg University of Mainz, 55128 Mainz, Germany
| | - Kristina Kastano
- Faculty of Biology, Johannes Gutenberg University of Mainz, 55128 Mainz, Germany
| | - Pablo Mier
- Faculty of Biology, Johannes Gutenberg University of Mainz, 55128 Mainz, Germany
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12
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Kastano K, Mier P, Andrade-Navarro MA. The Role of Low Complexity Regions in Protein Interaction Modes: An Illustration in Huntingtin. Int J Mol Sci 2021; 22:1727. [PMID: 33572172 PMCID: PMC7915032 DOI: 10.3390/ijms22041727] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 01/25/2021] [Accepted: 02/04/2021] [Indexed: 12/11/2022] Open
Abstract
Low complexity regions (LCRs) are very frequent in protein sequences, generally having a lower propensity to form structured domains and tending to be much less evolutionarily conserved than globular domains. Their higher abundance in eukaryotes and in species with more cellular types agrees with a growing number of reports on their function in protein interactions regulated by post-translational modifications. LCRs facilitate the increase of regulatory and network complexity required with the emergence of organisms with more complex tissue distribution and development. Although the low conservation and structural flexibility of LCRs complicate their study, evolutionary studies of proteins across species have been used to evaluate their significance and function. To investigate how to apply this evolutionary approach to the study of LCR function in protein-protein interactions, we performed a detailed analysis for Huntingtin (HTT), a large protein that is a hub for interaction with hundreds of proteins, has a variety of LCRs, and for which partial structural information (in complex with HAP40) is available. We hypothesize that proteins RASA1, SYN2, and KAT2B may compete with HAP40 for their attachment to the core of HTT using similar LCRs. Our results illustrate how evolution might favor the interplay of LCRs with domains, and the possibility of detecting multiple modes of LCR-mediated protein-protein interactions with a large hub such as HTT when enough protein interaction data is available.
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Affiliation(s)
| | | | - Miguel A. Andrade-Navarro
- Institute of Organismic and Molecular Evolution, Faculty of Biology, Johannes Gutenberg University of Mainz, 55128 Mainz, Germany; (K.K.); (P.M.)
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13
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Wilhelmi I, Grunwald S, Gimber N, Popp O, Dittmar G, Arumughan A, Wanker EE, Laeger T, Schmoranzer J, Daumke O, Schürmann A. The ARFRP1-dependent Golgi scaffolding protein GOPC is required for insulin secretion from pancreatic β-cells. Mol Metab 2020; 45:101151. [PMID: 33359402 PMCID: PMC7811047 DOI: 10.1016/j.molmet.2020.101151] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 12/15/2020] [Accepted: 12/15/2020] [Indexed: 12/13/2022] Open
Abstract
Objective Hormone secretion from metabolically active tissues, such as pancreatic islets, is governed by specific and highly regulated signaling pathways. Defects in insulin secretion are among the major causes of diabetes. The molecular mechanisms underlying regulated insulin secretion are, however, not yet completely understood. In this work, we studied the role of the GTPase ARFRP1 on insulin secretion from pancreatic β-cells. Methods A β-cell-specific Arfrp1 knockout mouse was phenotypically characterized. Pulldown experiments and mass spectrometry analysis were employed to screen for new ARFRP1-interacting proteins. Co-immunoprecipitation assays as well as super-resolution microscopy were applied for validation. Results The GTPase ARFRP1 interacts with the Golgi-associated PDZ and coiled-coil motif-containing protein (GOPC). Both proteins are co-localized at the trans-Golgi network and regulate the first and second phase of insulin secretion by controlling the plasma membrane localization of the SNARE protein SNAP25. Downregulation of both GOPC and ARFRP1 in Min6 cells interferes with the plasma membrane localization of SNAP25 and enhances its degradation, thereby impairing glucose-stimulated insulin release from β-cells. In turn, overexpression of SNAP25 as well as GOPC restores insulin secretion in islets from β-cell-specific Arfrp1 knockout mice. Conclusion Our results identify a hitherto unrecognized pathway required for insulin secretion at the level of trans-Golgi sorting. β-cell specific deletion of the trans-Golgi residing small GTPase ARFRP1 leads to elevated blood glucose levels in mice. GOPC is a newly identified ARFRP1 dependent scaffolding protein. ARFRP1 and GOPC are required for glucose-stimulated insulin secretion from pancreatic β-cells.
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Affiliation(s)
- Ilka Wilhelmi
- German Institute of Human Nutrition (DIfE) Potsdam-Rehbruecke, Germany; German Center for Diabetes Research (DZD) Munich Neuherberg, Germany
| | - Stephan Grunwald
- Max-Delbrück Center for Molecular Medicine in the Helmholtz Association Berlin, Germany; Institute of Chemistry and Biochemistry, Freie Universität Berlin, Germany
| | - Niclas Gimber
- Advanced Medical Bioimaging Core Facility - AMBIO, Charité-Universitätsmedizin Berlin, Germany
| | - Oliver Popp
- Max-Delbrück Center for Molecular Medicine in the Helmholtz Association Berlin, Germany
| | - Gunnar Dittmar
- Max-Delbrück Center for Molecular Medicine in the Helmholtz Association Berlin, Germany
| | - Anup Arumughan
- Neuroproteomics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC) Berlin, Germany
| | - Erich E Wanker
- Neuroproteomics, Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC) Berlin, Germany
| | - Thomas Laeger
- German Institute of Human Nutrition (DIfE) Potsdam-Rehbruecke, Germany; German Center for Diabetes Research (DZD) Munich Neuherberg, Germany
| | - Jan Schmoranzer
- Advanced Medical Bioimaging Core Facility - AMBIO, Charité-Universitätsmedizin Berlin, Germany
| | - Oliver Daumke
- Max-Delbrück Center for Molecular Medicine in the Helmholtz Association Berlin, Germany; Institute of Chemistry and Biochemistry, Freie Universität Berlin, Germany
| | - Annette Schürmann
- German Institute of Human Nutrition (DIfE) Potsdam-Rehbruecke, Germany; German Center for Diabetes Research (DZD) Munich Neuherberg, Germany; University of Potsdam, Institute of Nutritional Sciences, Nuthetal, Germany; Faculty of Health Sciences, Joint Faculty of the Brandenburg University of Technology Cottbus - Senftenberg, the Brandenburg Medical School Theodor Fontane and the University of Potsdam, Germany.
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Tomczyk M, Glaser T, Ulrich H, Slominska EM, Smolenski RT. Huntingtin protein maintains balanced energetics in mouse cardiomyocytes. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2020; 41:231-238. [PMID: 32933349 DOI: 10.1080/15257770.2020.1815769] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Huntingtin (HTT) is a multifunctional protein crucial for proper embryogenesis and nervous system development. Mutation of a single allele in gene coded this protein results in the Huntington׳s disease (HD). There is growing evidence of cardiovascular system pathologies coexisting with the neurological symptoms in HD patients. Thus, this study aims to establish the role of huntingtin protein in cardiomyocytes cellular energy and nucleotides metabolism. We used HTT KO mice embryonic stem cells (ESC) obtained with CRISPR method, wild type mice ESC treated by CRISPR with Scramble control sequence (SCR) as well as wild type (WT) mice ESC and differentiate it into cardiomyocytes. Analysis of intracellular concentration of ATP, ADP, and NAD+, as well as nucleotide catabolites were performed with HPLC. We noted that HTT null cardiomyocytes showed diminished intracellular ATP (4.9 ± 0.5; 6.7 ± 0.4 nmol/mg protein HTT KO vs. SCR) and NAD+ (0.9 ± 0.1; 1.6 ± 0.1 nmol/mg HTT KO vs. SCR). We noted also reduced cellular medium concentration of total purines pool (17.1 ± 1.7; 24.7 ± 2.7 nmol/ml HTT KO vs. SCR) as well as IMP concentration (7.7 ± 0.6; 10.2 ± 0.4 nmol/ml HTT KO vs. SCR). This study indicates that HTT plays an important role in cellular energy balance as well as in nucleotide metabolism in cardiomyocytes. Furthermore, our findings underline that the deterioration in energy metabolism observed in HD may be caused not only by cellular mutant HTT accumulation but also by the loss of HTT function.
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Affiliation(s)
- Marta Tomczyk
- Department of Biochemistry, Medical University of Gdansk, Gdansk, Poland
| | - Talita Glaser
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | - Henning Ulrich
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | - Ewa M Slominska
- Department of Biochemistry, Medical University of Gdansk, Gdansk, Poland
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15
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Tabrizi SJ, Flower MD, Ross CA, Wild EJ. Huntington disease: new insights into molecular pathogenesis and therapeutic opportunities. Nat Rev Neurol 2020; 16:529-546. [PMID: 32796930 DOI: 10.1038/s41582-020-0389-4] [Citation(s) in RCA: 241] [Impact Index Per Article: 60.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/29/2020] [Indexed: 12/11/2022]
Abstract
Huntington disease (HD) is a neurodegenerative disease caused by CAG repeat expansion in the huntingtin gene (HTT) and involves a complex web of pathogenic mechanisms. Mutant HTT (mHTT) disrupts transcription, interferes with immune and mitochondrial function, and is aberrantly modified post-translationally. Evidence suggests that the mHTT RNA is toxic, and at the DNA level, somatic CAG repeat expansion in vulnerable cells influences the disease course. Genome-wide association studies have identified DNA repair pathways as modifiers of somatic instability and disease course in HD and other repeat expansion diseases. In animal models of HD, nucleocytoplasmic transport is disrupted and its restoration is neuroprotective. Novel cerebrospinal fluid (CSF) and plasma biomarkers are among the earliest detectable changes in individuals with premanifest HD and have the sensitivity to detect therapeutic benefit. Therapeutically, the first human trial of an HTT-lowering antisense oligonucleotide successfully, and safely, reduced the CSF concentration of mHTT in individuals with HD. A larger trial, powered to detect clinical efficacy, is underway, along with trials of other HTT-lowering approaches. In this Review, we discuss new insights into the molecular pathogenesis of HD and future therapeutic strategies, including the modulation of DNA repair and targeting the DNA mutation itself.
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Affiliation(s)
- Sarah J Tabrizi
- Huntington's Disease Centre, University College London, London, UK. .,Department of Neurodegenerative Disease, Queen Square Institute of Neurology, University College London, London, UK. .,UK Dementia Research Institute, University College London, London, UK.
| | - Michael D Flower
- Huntington's Disease Centre, University College London, London, UK.,Department of Neurodegenerative Disease, Queen Square Institute of Neurology, University College London, London, UK.,UK Dementia Research Institute, University College London, London, UK
| | - Christopher A Ross
- Departments of Neurology, Neuroscience and Pharmacology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Edward J Wild
- Huntington's Disease Centre, University College London, London, UK.,Department of Neurodegenerative Disease, Queen Square Institute of Neurology, University College London, London, UK
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16
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Chaves G, Stanley J, Pourmand N. Mutant Huntingtin Affects Diabetes and Alzheimer's Markers in Human and Cell Models of Huntington's Disease. Cells 2019; 8:E962. [PMID: 31450785 PMCID: PMC6769852 DOI: 10.3390/cells8090962] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 08/14/2019] [Accepted: 08/21/2019] [Indexed: 02/07/2023] Open
Abstract
A higher incidence of diabetes was observed among family members of individuals affected by Huntington's Disease with no follow-up studies investigating the genetic nature of the observation. Using a genome-wide association study (GWAS), RNA sequencing (RNA-Seq) analysis and western blotting of Rattus norvegicus and human, we were able to identify that the gene family of sortilin receptors was affected in Huntington's Disease patients. We observed that less than 5% of SNPs were of statistical significance and that sortilins and HLA/MHC gene expression or SNPs were associated with mutant huntingtin (mHTT). These results suggest that ST14A cells derived from R. norvegicus are a reliable model of HD, since sortilins were identified through analysis of the transcriptome in these cells. These findings help highlight the genes involved in mechanisms targeted by diabetes drugs, such as glucose transporters as well as proteins controlling insulin release related to mHTT. To the best of our knowledge, this is the first GWAS using RNA-Seq data from both ST14A rat HD cell model and human Huntington's Disease.
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Affiliation(s)
- Gepoliano Chaves
- Department of Biomolecular Engineering, University of California, Santa Cruz, CA 95064, USA
| | - John Stanley
- Department of Biomolecular Engineering, University of California, Santa Cruz, CA 95064, USA
| | - Nader Pourmand
- Department of Biomolecular Engineering, University of California, Santa Cruz, CA 95064, USA.
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17
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Tellone E, Galtieri A, Ficarra S. Reviewing Biochemical Implications of Normal and Mutated Huntingtin in Huntington's Disease. Curr Med Chem 2019; 27:5137-5158. [PMID: 31223078 DOI: 10.2174/0929867326666190621101909] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 05/08/2019] [Accepted: 05/22/2019] [Indexed: 12/17/2022]
Abstract
Huntingtin (Htt) is a multi-function protein of the brain. Normal Htt shows a common alpha-helical structure but conformational changes in the form with beta strands are the principal cause of Huntington's disease. Huntington's disease is a genetic neurological disorder caused by a repeated expansion of the CAG trinucleotide, causing instability in the N-terminal of the gene coding for the Huntingtin protein. The mutation leads to the abnormal expansion of the production of the polyglutamine tract (polyQ) resulting in the form of an unstable Huntingtin protein commonly referred to as mutant Huntingtin. Mutant Huntingtin is the cause of the complex neurological metabolic alteration of Huntington's disease, resulting in both the loss of all the functions of normal Huntingtin and the genesis of abnormal interactions due to the presence of this mutation. One of the problems arising from the misfolded Huntingtin is the increase in oxidative stress, which is common in many neurological diseases such as Alzheimer's, Parkinson's, Amyotrophic Lateral Sclerosis and Creutzfeldt-Jakob disease. In the last few years, the use of antioxidants had a strong incentive to find valid therapies for defence against neurodegenerations. Although further studies are needed, the use of antioxidant mixtures to counteract neuronal damages seems promising.
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Affiliation(s)
- Ester Tellone
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, V.le Ferdinando Stagno d'Alcontres 31, 98166 Messina, Italy
| | - Antonio Galtieri
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, V.le Ferdinando Stagno d'Alcontres 31, 98166 Messina, Italy
| | - Silvana Ficarra
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, V.le Ferdinando Stagno d'Alcontres 31, 98166 Messina, Italy
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18
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McClory H, Wang X, Sapp E, Gatune LW, Iuliano M, Wu CY, Nathwani G, Kegel-Gleason KB, DiFiglia M, Li X. The COOH-terminal domain of huntingtin interacts with RhoGEF kalirin and modulates cell survival. Sci Rep 2018; 8:8000. [PMID: 29789657 PMCID: PMC5964228 DOI: 10.1038/s41598-018-26255-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 05/01/2018] [Indexed: 12/14/2022] Open
Abstract
Human huntingtin (Htt) contains 3144 amino acids and has an expanded polyglutamine region near the NH2-terminus in patients with Huntington's disease. While numerous binding partners have been identified to NH2-terminal Htt, fewer proteins are known to interact with C-terminal domains of Htt. Here we report that kalirin, a Rac1 activator, is a binding partner to C-terminal Htt. Kalirin and Htt co-precipitated from mouse brain endosomes and co-localized at puncta in NRK and immortalized striatal cells and primary cortical neurons. We mapped the interaction domains to kalirin674-1272 and Htt2568-3144 and determined that the interaction between kalirin and Htt was independent of HAP1, a known interactor for Htt and kalirin. Kalirin precipitated with mutant Htt was more abundant than with wild-type Htt and had a reduced capacity to activate Rac1 when mutant Htt was present. Expression of Htt2568-3144 caused cytotoxicity, partially rescued by co-expressing kalirin674-1272 but not other regions of kalirin. Our study suggests that the interaction of kalirin with the C-terminal region of Htt influences the function of kalirin and modulates the cytotoxicity induced by C-terminal Htt.
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Affiliation(s)
- Hollis McClory
- Laboratory of Cellular Neurobiology and Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Xiaolong Wang
- School of Pharmacy, Shanghai Jiao Tong University, Minhang District, Shanghai, China
| | - Ellen Sapp
- Laboratory of Cellular Neurobiology and Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Leah W Gatune
- Laboratory of Cellular Neurobiology and Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Maria Iuliano
- Laboratory of Cellular Neurobiology and Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Chiu-Yi Wu
- Laboratory of Cellular Neurobiology and Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Gina Nathwani
- Laboratory of Cellular Neurobiology and Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Kimberly B Kegel-Gleason
- Laboratory of Cellular Neurobiology and Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Marian DiFiglia
- Laboratory of Cellular Neurobiology and Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Xueyi Li
- Laboratory of Cellular Neurobiology and Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA.
- School of Pharmacy, Shanghai Jiao Tong University, Minhang District, Shanghai, China.
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19
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Caterino M, Squillaro T, Montesarchio D, Giordano A, Giancola C, Melone MAB. Huntingtin protein: A new option for fixing the Huntington's disease countdown clock. Neuropharmacology 2018. [PMID: 29526547 DOI: 10.1016/j.neuropharm.2018.03.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Huntington's disease is a dreadful, incurable disorder. It springs from the autosomal dominant mutation in the first exon of the HTT gene, which encodes for the huntingtin protein (HTT) and results in progressive neurodegeneration. Thus far, all the attempted approaches to tackle the mutant HTT-induced toxicity causing this disease have failed. The mutant protein comes with the aberrantly expanded poly-glutamine tract. It is primarily to blame for the build-up of β-amyloid-like HTT aggregates, deleterious once broadened beyond the critical ∼35-37 repeats threshold. Recent experimental findings have provided valuable information on the molecular basis underlying this HTT-driven neurodegeneration. These findings indicate that the poly-glutamine siding regions and many post-translation modifications either abet or counter the poly-glutamine tract. This review provides an overall, up-to-date insight into HTT biophysics and structural biology, particularly discussing novel pharmacological options to specifically target the mutated protein and thus inhibit its functions and toxicity.
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Affiliation(s)
- Marco Caterino
- Department of Pharmacy, University of Napoli Federico II, Via D. Montesano 49, 80131, Napoli, Italy
| | - Tiziana Squillaro
- Department of Medical, Surgical, Neurological, Metabolic Sciences, and Aging, 2nd Division of Neurology, Center for Rare Diseases, University of Campania "Luigi Vanvitelli", Napoli, Italy; InterUniversity Center for Research in Neurosciences, University of Campania "Luigi Vanvitelli", Napoli, Italy
| | - Daniela Montesarchio
- InterUniversity Center for Research in Neurosciences, University of Campania "Luigi Vanvitelli", Napoli, Italy; Department of Chemical Sciences, University of Napoli Federico II, Via Cintia 21, 80126, Napoli, Italy
| | - Antonio Giordano
- Sbarro Institute for Cancer Research and Molecular Medicine, Department of Biology, Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, PA, USA; Department of Medicine, Surgery and Neuroscience University of Siena, Siena, Italy
| | - Concetta Giancola
- Department of Pharmacy, University of Napoli Federico II, Via D. Montesano 49, 80131, Napoli, Italy; InterUniversity Center for Research in Neurosciences, University of Campania "Luigi Vanvitelli", Napoli, Italy.
| | - Mariarosa A B Melone
- Department of Medical, Surgical, Neurological, Metabolic Sciences, and Aging, 2nd Division of Neurology, Center for Rare Diseases, University of Campania "Luigi Vanvitelli", Napoli, Italy; InterUniversity Center for Research in Neurosciences, University of Campania "Luigi Vanvitelli", Napoli, Italy; Sbarro Institute for Cancer Research and Molecular Medicine, Department of Biology, Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, PA, USA.
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20
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Abstract
Huntingtin (Htt) is a large (348 kDa) protein, essential for embryonic
development and involved in diverse cellular activities such as vesicular
transport, endocytosis, autophagy and transcription regulation1,2.
While an integrative understanding of Htt's biological functions is
lacking, the large number of identified interactors suggests that Htt serves as
a protein-protein interaction hub1,3,4.
Furthermore, Huntington’s disease is caused by a mutation in the Htt
gene, resulting in a pathogenic expansion of a polyglutamine (polyQ) repeat at
the N-terminus of Htt5,6. However, only limited structural
information on Htt is currently available. Here we employed cryo-electron
microscopy (cryo-EM) to determine the structure of full-length human Htt in a
complex with HAP40/F8A7 to 4 Å
resolution. Htt is largely α-helical and consists of three major domains.
The N- and C-terminal domains contain multiple HEAT repeats arranged in a
solenoid fashion. These domains are connected by a smaller bridge domain
containing different types of tandem repeats. HAP40 is also largely
α-helical and has a tetratricopeptide repeat (TPR)-like organization.
HAP40 binds in a cleft contacting the three Htt domains by hydrophobic and
electrostatic interactions, thereby stabilizing Htt conformation. These data
rationalize previous biochemical results and pave the way for an improved
understanding of Htt’s diverse cellular functions.
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21
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Sirtuins as Modifiers of Huntington's Disease (HD) Pathology. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2018; 154:105-145. [DOI: 10.1016/bs.pmbts.2017.11.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Brandi V, Di Lella V, Marino M, Ascenzi P, Polticelli F. A comprehensive in silico analysis of huntingtin and its interactome. J Biomol Struct Dyn 2017; 36:3155-3171. [PMID: 28920551 DOI: 10.1080/07391102.2017.1381646] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
A polyglutamine expansion of the N-terminal region of huntingtin (Htt) causes Huntington's disease, a severe neurodegenerative disorder. Htt huge multidomain structure, the presence of disordered regions, and the lack of sequence homologs of known structure, so far prevented structural studies of Htt, making the study of its structure-function relationships very difficult. In this work, the presence and location of five Htt ordered domains (named from Hunt1 to Hunt5) has been detected and the structure of these domains has been predicted for the first time using a combined threading/ab initio modeling approach. This work has led to the identification of a previously undetected HEAT repeats region in the Hunt3 domain. Furthermore, a putative function has been assigned to four out of the five domains. Hunt1 and Hunt5, displaying structural similarity with the regulatory subunit A of protein phosphatase 2A, are predicted to play a role in regulating the phosphorylation status of cellular proteins. Hunt2 and Hunt3 are predicted to be homologs of two yeast importins and to mediate vescicles transport and protein trafficking. Finally, a comprehensive analysis of the Htt interactome has been carried out and is discussed to provide a global picture of the Htt's structure-function relationships.
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Affiliation(s)
- Valentina Brandi
- a Department of Sciences , Roma Tre University, Viale Guglielmo Marconi 446 , Roma I-00146 , Italy
| | - Valentina Di Lella
- a Department of Sciences , Roma Tre University, Viale Guglielmo Marconi 446 , Roma I-00146 , Italy
| | - Maria Marino
- a Department of Sciences , Roma Tre University, Viale Guglielmo Marconi 446 , Roma I-00146 , Italy
| | - Paolo Ascenzi
- a Department of Sciences , Roma Tre University, Viale Guglielmo Marconi 446 , Roma I-00146 , Italy.,b Interdepartmental Laboratory for Electron Microscopy , Roma Tre University , Roma I-00146 , Italy
| | - Fabio Polticelli
- a Department of Sciences , Roma Tre University, Viale Guglielmo Marconi 446 , Roma I-00146 , Italy.,c National Institute of Nuclear Physics , Roma Tre University, Roma Tre Section , Roma I-00146 , Italy
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Pugacheva V, Korotkov A, Korotkov E. Search of latent periodicity in amino acid sequences by means of genetic algorithm and dynamic programming. Stat Appl Genet Mol Biol 2017; 15:381-400. [PMID: 27337743 DOI: 10.1515/sagmb-2015-0079] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The aim of this study was to show that amino acid sequences have a latent periodicity with insertions and deletions of amino acids in unknown positions of the analyzed sequence. Genetic algorithm, dynamic programming and random weight matrices were used to develop a new mathematical algorithm for latent periodicity search. A multiple alignment of periods was calculated with help of the direct optimization of the position-weight matrix without using pairwise alignments. The developed algorithm was applied to analyze amino acid sequences of a small number of proteins. This study showed the presence of latent periodicity with insertions and deletions in the amino acid sequences of such proteins, for which the presence of latent periodicity was not previously known. The origin of latent periodicity with insertions and deletions is discussed.
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Huntingtin polyQ Mutation Impairs the 17β-Estradiol/Neuroglobin Pathway Devoted to Neuron Survival. Mol Neurobiol 2016; 54:6634-6646. [DOI: 10.1007/s12035-016-0337-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 11/30/2016] [Indexed: 02/07/2023]
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26
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Riechers SP, Butland S, Deng Y, Skotte N, Ehrnhoefer DE, Russ J, Laine J, Laroche M, Pouladi MA, Wanker EE, Hayden MR, Graham RK. Interactome network analysis identifies multiple caspase-6 interactors involved in the pathogenesis of HD. Hum Mol Genet 2016; 25:1600-18. [DOI: 10.1093/hmg/ddw036] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 02/05/2016] [Indexed: 11/14/2022] Open
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Schütze T, Ulrich AKC, Apelt L, Will CL, Bartlick N, Seeger M, Weber G, Lührmann R, Stelzl U, Wahl MC. Multiple protein-protein interactions converging on the Prp38 protein during activation of the human spliceosome. RNA (NEW YORK, N.Y.) 2016; 22:265-77. [PMID: 26673105 PMCID: PMC4712676 DOI: 10.1261/rna.054296.115] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 11/17/2015] [Indexed: 05/22/2023]
Abstract
Spliceosomal Prp38 proteins contain a conserved amino-terminal domain, but only higher eukaryotic orthologs also harbor a carboxy-terminal RS domain, a hallmark of splicing regulatory SR proteins. We show by crystal structure analysis that the amino-terminal domain of human Prp38 is organized around three pairs of antiparallel α-helices and lacks similarities to RNA-binding domains found in canonical SR proteins. Instead, yeast two-hybrid analyses suggest that the amino-terminal domain is a versatile protein-protein interaction hub that possibly binds 12 other spliceosomal proteins, most of which are recruited at the same stage as Prp38. By quantitative, alanine surface-scanning two-hybrid screens and biochemical analyses we delineated four distinct interfaces on the Prp38 amino-terminal domain. In vitro interaction assays using recombinant proteins showed that Prp38 can bind at least two proteins simultaneously via two different interfaces. Addition of excess Prp38 amino-terminal domain to in vitro splicing assays, but not of an interaction-deficient mutant, stalled splicing at a precatalytic stage. Our results show that human Prp38 is an unusual SR protein, whose amino-terminal domain is a multi-interface protein-protein interaction platform that might organize the relative positioning of other proteins during splicing.
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Affiliation(s)
- Tonio Schütze
- Freie Universität Berlin, Laboratory of Structural Biochemistry, D-14195 Berlin, Germany
| | - Alexander K C Ulrich
- Freie Universität Berlin, Laboratory of Structural Biochemistry, D-14195 Berlin, Germany
| | - Luise Apelt
- Max-Planck Institute for Molecular Genetics, Otto-Warburg Laboratory, D-14195 Berlin, Germany
| | - Cindy L Will
- Max Planck Institute for Biophysical Chemistry, Department of Cellular Biochemistry, D-37077 Göttingen, Germany
| | - Natascha Bartlick
- Freie Universität Berlin, Laboratory of Structural Biochemistry, D-14195 Berlin, Germany
| | - Martin Seeger
- Freie Universität Berlin, Laboratory of Structural Biochemistry, D-14195 Berlin, Germany
| | - Gert Weber
- Freie Universität Berlin, Laboratory of Structural Biochemistry, D-14195 Berlin, Germany
| | - Reinhard Lührmann
- Max Planck Institute for Biophysical Chemistry, Department of Cellular Biochemistry, D-37077 Göttingen, Germany
| | - Ulrich Stelzl
- Max-Planck Institute for Molecular Genetics, Otto-Warburg Laboratory, D-14195 Berlin, Germany University of Graz, Institute of Pharmaceutical Sciences (IPW), Pharmaceutical Chemistry, A-8010 Graz, Austria
| | - Markus C Wahl
- Freie Universität Berlin, Laboratory of Structural Biochemistry, D-14195 Berlin, Germany
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Pellegrini M. Tandem Repeats in Proteins: Prediction Algorithms and Biological Role. Front Bioeng Biotechnol 2015; 3:143. [PMID: 26442257 PMCID: PMC4585158 DOI: 10.3389/fbioe.2015.00143] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 09/07/2015] [Indexed: 12/30/2022] Open
Abstract
Tandem repetitions in protein sequence and structure is a fascinating subject of research which has been a focus of study since the late 1990s. In this survey, we give an overview on the multi-faceted aspects of research on protein tandem repeats (PTR for short), including prediction algorithms, databases, early classification efforts, mechanisms of PTR formation and evolution, and synthetic PTR design. We also touch on the rather open issue of the relationship between PTR and flexibility (or disorder) in proteins. Detection of PTR either from protein sequence or structure data is challenging due to inherent high (biological) signal-to-noise ratio that is a key feature of this problem. As early in silico analytic tools have been key enablers for starting this field of study, we expect that current and future algorithmic and statistical breakthroughs will have a high impact on the investigations of the biological role of PTR.
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Affiliation(s)
- Marco Pellegrini
- Laboratory for Integrative Systems Medicine (LISM), Istituto di Informatica e Telematica, and Istituto di Fisiologia Clinica, Consiglio Nazionale delle Ricerche , Pisa , Italy
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29
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Trepte P, Buntru A, Klockmeier K, Willmore L, Arumughan A, Secker C, Zenkner M, Brusendorf L, Rau K, Redel A, Wanker EE. DULIP: A Dual Luminescence-Based Co-Immunoprecipitation Assay for Interactome Mapping in Mammalian Cells. J Mol Biol 2015; 427:3375-88. [PMID: 26264872 DOI: 10.1016/j.jmb.2015.08.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 07/31/2015] [Accepted: 08/03/2015] [Indexed: 12/30/2022]
Abstract
Mapping of protein-protein interactions (PPIs) is critical for understanding protein function and complex biological processes. Here, we present DULIP, a dual luminescence-based co-immunoprecipitation assay, for systematic PPI mapping in mammalian cells. DULIP is a second-generation luminescence-based PPI screening method for the systematic and quantitative analysis of co-immunoprecipitations using two different luciferase tags. Benchmarking studies with positive and negative PPI reference sets revealed that DULIP allows the detection of interactions with high sensitivity and specificity. Furthermore, the analysis of a PPI reference set with known binding affinities demonstrated that both low- and high-affinity interactions can be detected with DULIP assays. Finally, using the well-characterized interaction between Syntaxin-1 and Munc18, we found that DULIP is capable of detecting the effects of point mutations on interaction strength. Taken together, our studies demonstrate that DULIP is a sensitive and reliable method of great utility for systematic interactome research. It can be applied for interaction screening and validation of PPIs in mammalian cells. Moreover, DULIP permits the specific analysis of mutation-dependent binding patterns.
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Affiliation(s)
- Philipp Trepte
- Neuroproteomics, Max Delbrueck Center for Molecular Medicine, Robert-Roessle-Straße 10, 13125 Berlin, Germany
| | - Alexander Buntru
- Neuroproteomics, Max Delbrueck Center for Molecular Medicine, Robert-Roessle-Straße 10, 13125 Berlin, Germany
| | - Konrad Klockmeier
- Neuroproteomics, Max Delbrueck Center for Molecular Medicine, Robert-Roessle-Straße 10, 13125 Berlin, Germany
| | - Lindsay Willmore
- Neuroproteomics, Max Delbrueck Center for Molecular Medicine, Robert-Roessle-Straße 10, 13125 Berlin, Germany
| | - Anup Arumughan
- Neuroproteomics, Max Delbrueck Center for Molecular Medicine, Robert-Roessle-Straße 10, 13125 Berlin, Germany
| | - Christopher Secker
- Neuroproteomics, Max Delbrueck Center for Molecular Medicine, Robert-Roessle-Straße 10, 13125 Berlin, Germany
| | - Martina Zenkner
- Neuroproteomics, Max Delbrueck Center for Molecular Medicine, Robert-Roessle-Straße 10, 13125 Berlin, Germany
| | - Lydia Brusendorf
- Neuroproteomics, Max Delbrueck Center for Molecular Medicine, Robert-Roessle-Straße 10, 13125 Berlin, Germany
| | - Kirstin Rau
- Neuroproteomics, Max Delbrueck Center for Molecular Medicine, Robert-Roessle-Straße 10, 13125 Berlin, Germany
| | - Alexandra Redel
- Neuroproteomics, Max Delbrueck Center for Molecular Medicine, Robert-Roessle-Straße 10, 13125 Berlin, Germany
| | - Erich E Wanker
- Neuroproteomics, Max Delbrueck Center for Molecular Medicine, Robert-Roessle-Straße 10, 13125 Berlin, Germany.
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El-Daher MT, Hangen E, Bruyère J, Poizat G, Al-Ramahi I, Pardo R, Bourg N, Souquere S, Mayet C, Pierron G, Lévêque-Fort S, Botas J, Humbert S, Saudou F. Huntingtin proteolysis releases non-polyQ fragments that cause toxicity through dynamin 1 dysregulation. EMBO J 2015; 34:2255-71. [PMID: 26165689 DOI: 10.15252/embj.201490808] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 06/12/2015] [Indexed: 12/11/2022] Open
Abstract
Cleavage of mutant huntingtin (HTT) is an essential process in Huntington's disease (HD), an inherited neurodegenerative disorder. Cleavage generates N-ter fragments that contain the polyQ stretch and whose nuclear toxicity is well established. However, the functional defects induced by cleavage of full-length HTT remain elusive. Moreover, the contribution of non-polyQ C-terminal fragments is unknown. Using time- and site-specific control of full-length HTT proteolysis, we show that specific cleavages are required to disrupt intramolecular interactions within HTT and to cause toxicity in cells and flies. Surprisingly, in addition to the canonical pathogenic N-ter fragments, the C-ter fragments generated, that do not contain the polyQ stretch, induced toxicity via dilation of the endoplasmic reticulum (ER) and increased ER stress. C-ter HTT bound to dynamin 1 and subsequently impaired its activity at ER membranes. Our findings support a role for HTT on dynamin 1 function and ER homoeostasis. Proteolysis-induced alteration of this function may be relevant to disease.
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Affiliation(s)
| | - Emilie Hangen
- Institut Curie, Orsay, France CNRS UMR3306, Orsay, France INSERM U1005, Orsay, France
| | - Julie Bruyère
- Institut Curie, Orsay, France CNRS UMR3306, Orsay, France INSERM U1005, Orsay, France Inserm U836, Grenoble, France Grenoble Institut des Neurosciences, GIN University of Grenoble Alpes, Grenoble, France
| | - Ghislaine Poizat
- Institut Curie, Orsay, France CNRS UMR3306, Orsay, France INSERM U1005, Orsay, France
| | - Ismael Al-Ramahi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Raul Pardo
- Institut Curie, Orsay, France CNRS UMR3306, Orsay, France INSERM U1005, Orsay, France
| | - Nicolas Bourg
- ISMO, CNRS UMR8214 University of Paris Sud, Orsay, France CPBM FR2764 University of Paris Sud, Orsay, France
| | - Sylvie Souquere
- CNRS UMR8122, Villejuif, France Institut Gustave Roussy, Villejuif, France
| | - Céline Mayet
- ISMO, CNRS UMR8214 University of Paris Sud, Orsay, France CPBM FR2764 University of Paris Sud, Orsay, France
| | - Gérard Pierron
- CNRS UMR8122, Villejuif, France Institut Gustave Roussy, Villejuif, France
| | - Sandrine Lévêque-Fort
- ISMO, CNRS UMR8214 University of Paris Sud, Orsay, France CPBM FR2764 University of Paris Sud, Orsay, France
| | - Juan Botas
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Sandrine Humbert
- Institut Curie, Orsay, France CNRS UMR3306, Orsay, France INSERM U1005, Orsay, France Inserm U836, Grenoble, France Grenoble Institut des Neurosciences, GIN University of Grenoble Alpes, Grenoble, France
| | - Frédéric Saudou
- Institut Curie, Orsay, France CNRS UMR3306, Orsay, France INSERM U1005, Orsay, France Inserm U836, Grenoble, France Grenoble Institut des Neurosciences, GIN University of Grenoble Alpes, Grenoble, France CHU de Grenoble, Grenoble, France
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31
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Abstract
Amino acid repeats (AARs) are abundant in protein sequences. They have particular roles in protein function and evolution. Simple repeat patterns generated by DNA slippage tend to introduce length variations and point mutations in repeat regions. Loss of normal and gain of abnormal function owing to their variable length are potential risks leading to diseases. Repeats with complex patterns mostly refer to the functional domain repeats, such as the well-known leucine-rich repeat and WD repeat, which are frequently involved in protein–protein interaction. They are mainly derived from internal gene duplication events and stabilized by ‘gate-keeper’ residues, which play crucial roles in preventing inter-domain aggregation. AARs are widely distributed in different proteomes across a variety of taxonomic ranges, and especially abundant in eukaryotic proteins. However, their specific evolutionary and functional scenarios are still poorly understood. Identifying AARs in protein sequences is the first step for the further investigation of their biological function and evolutionary mechanism. In principle, this is an NP-hard problem, as most of the repeat fragments are shaped by a series of sophisticated evolutionary events and become latent periodical patterns. It is not possible to define a uniform criterion for detecting and verifying various repeat patterns. Instead, different algorithms based on different strategies have been developed to cope with different repeat patterns. In this review, we attempt to describe the amino acid repeat-detection algorithms currently available and compare their strategies based on an in-depth analysis of the biological significance of protein repeats.
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Scalable production in human cells and biochemical characterization of full-length normal and mutant huntingtin. PLoS One 2015; 10:e0121055. [PMID: 25799558 PMCID: PMC4370734 DOI: 10.1371/journal.pone.0121055] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 01/29/2015] [Indexed: 11/21/2022] Open
Abstract
Huntingtin (Htt) is a 350 kD intracellular protein, ubiquitously expressed and mainly localized in the cytoplasm. Huntington’s disease (HD) is caused by a CAG triplet amplification in exon 1 of the corresponding gene resulting in a polyglutamine (polyQ) expansion at the N-terminus of Htt. Production of full-length Htt has been difficult in the past and so far a scalable system or process has not been established for recombinant production of Htt in human cells. The ability to produce Htt in milligram quantities would be a prerequisite for many biochemical and biophysical studies aiming in a better understanding of Htt function under physiological conditions and in case of mutation and disease. For scalable production of full-length normal (17Q) and mutant (46Q and 128Q) Htt we have established two different systems, the first based on doxycycline-inducible Htt expression in stable cell lines, the second on “gutless” adenovirus mediated gene transfer. Purified material has then been used for biochemical characterization of full-length Htt. Posttranslational modifications (PTMs) were determined and several new phosphorylation sites were identified. Nearly all PTMs in full-length Htt localized to areas outside of predicted alpha-solenoid protein regions. In all detected N-terminal peptides methionine as the first amino acid was missing and the second, alanine, was found to be acetylated. Differences in secondary structure between normal and mutant Htt, a helix-rich protein, were not observed in our study. Purified Htt tends to form dimers and higher order oligomers, thus resembling the situation observed with N-terminal fragments, although the mechanism of oligomer formation may be different.
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33
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Abstract
Vertebrate adherens junctions mediate cell–cell adhesion via a “classical” cadherin–catenin “core” complex, which is associated with and regulated by a functional network of proteins, collectively named the cadherin adhesome (“cadhesome”). The most basal metazoans have been shown to conserve the cadherin–catenin “core”, but little is known about the evolution of the cadhesome. Using a bioinformatics approach based on both sequence and structural analysis, we have traced the evolution of this larger network in 26 organisms, from the uni-cellular ancestors of metazoans, through basal metazoans, to vertebrates. Surprisingly, we show that approximately 70% of the cadhesome, including proteins with similarity to the catenins, predate metazoans. We found that the transition to multicellularity was accompanied by the appearance of a small number of adaptor proteins, and we show how these proteins may have helped to integrate pre-metazoan sub-networks via PDZ domain–peptide interactions. Finally, we found the increase in network complexity in higher metazoans to have been driven primarily by expansion of paralogs. In summary, our analysis helps to explain how the complex protein network associated with cadherin at adherens junctions first came together in the first metazoan and how it evolved into the even more complex mammalian cadhesome.
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Affiliation(s)
- Paul S Murray
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA Center of Computational Biology and Bioinformatics, Department of Systems Biology, Columbia University, Irving Cancer Research Center, New York, NY 10032, USA
| | - Ronen Zaidel-Bar
- Mechanobiology Institute Singapore, National University of Singapore, Singapore 117411 Department of Biomedical Engineering, National University of Singapore, Singapore 117575
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34
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Otte DM, Raskó T, Wang M, Dreiseidler M, Drews E, Schrage H, Wojtalla A, Höhfeld J, Wanker E, Zimmer A. Identification of the Mitochondrial MSRB2 as a Binding Partner of LG72. Cell Mol Neurobiol 2014; 34:1123-30. [DOI: 10.1007/s10571-014-0087-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Accepted: 07/10/2014] [Indexed: 11/29/2022]
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35
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Butland SL, Sanders SS, Schmidt ME, Riechers SP, Lin DTS, Martin DDO, Vaid K, Graham RK, Singaraja RR, Wanker EE, Conibear E, Hayden MR. The palmitoyl acyltransferase HIP14 shares a high proportion of interactors with huntingtin: implications for a role in the pathogenesis of Huntington's disease. Hum Mol Genet 2014; 23:4142-60. [PMID: 24705354 DOI: 10.1093/hmg/ddu137] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
HIP14 is the most highly conserved of 23 human palmitoyl acyltransferases (PATs) that catalyze the post-translational addition of palmitate to proteins, including huntingtin (HTT). HIP14 is dysfunctional in the presence of mutant HTT (mHTT), the causative gene for Huntington disease (HD), and we hypothesize that reduced palmitoylation of HTT and other HIP14 substrates contributes to the pathogenesis of the disease. Here we describe the yeast two-hybrid (Y2H) interactors of HIP14 in the first comprehensive study of interactors of a mammalian PAT. Unexpectedly, we discovered a highly significant overlap between HIP14 interactors and 370 published interactors of HTT, 4-fold greater than for control proteins (P = 8 × 10(-5)). Nearly half of the 36 shared interactors are already implicated in HD, supporting a direct link between HIP14 and the disease. The HIP14 Y2H interaction set is significantly enriched for palmitoylated proteins that are candidate substrates. We confirmed that three of them, GPM6A, and the Sprouty domain-containing proteins SPRED1 and SPRED3, are indeed palmitoylated by HIP14; the first enzyme known to palmitoylate these proteins. These novel substrates functions might be affected by reduced palmitoylation in HD. We also show that the vesicular cargo adapter optineurin, an established HTT-binding protein, co-immunoprecipitates with HIP14 but is not palmitoylated. mHTT leads to mislocalization of optineurin and aberrant cargo trafficking. Therefore, it is possible that optineurin regulates trafficking of HIP14 to its substrates. Taken together, our data raise the possibility that defective palmitoylation by HIP14 might be an important mechanism that contributes to the pathogenesis of HD.
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Affiliation(s)
- Stefanie L Butland
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada V5Z 4H4
| | - Shaun S Sanders
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada V5Z 4H4
| | - Mandi E Schmidt
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada V5Z 4H4
| | - Sean-Patrick Riechers
- Neuroproteomics, Max Delbrueck Center for Molecular Medicine, Berlin-Buch 13125, Germany
| | - David T S Lin
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada V5Z 4H4
| | - Dale D O Martin
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada V5Z 4H4
| | - Kuljeet Vaid
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada V5Z 4H4
| | - Rona K Graham
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada V5Z 4H4
| | - Roshni R Singaraja
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada V5Z 4H4
| | - Erich E Wanker
- Neuroproteomics, Max Delbrueck Center for Molecular Medicine, Berlin-Buch 13125, Germany
| | - Elizabeth Conibear
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada V5Z 4H4
| | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada V5Z 4H4
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36
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Sanders SS, Mui KKN, Sutton LM, Hayden MR. Identification of binding sites in Huntingtin for the Huntingtin Interacting Proteins HIP14 and HIP14L. PLoS One 2014; 9:e90669. [PMID: 24651384 PMCID: PMC3947954 DOI: 10.1371/journal.pone.0090669] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Accepted: 02/04/2014] [Indexed: 11/26/2022] Open
Abstract
Huntington disease is an adult onset neurodegenerative disease characterized by motor, cognitive, and psychiatric dysfunction, caused by a CAG expansion in the HTT gene. Huntingtin Interacting Protein 14 (HIP14) and Huntingtin Interacting Protein 14-like (HIP14L) are palmitoyl acyltransferases (PATs), enzymes that mediate the post-translational addition of long chain fatty acids to proteins in a process called palmitoylation. HIP14 and HIP14L interact with and palmitoylate HTT and are unique among PATs as they are the only two that have an ankyrin repeat domain, which mediates the interaction between HIP14 and HTT. These enzymes show reduced interaction with and palmitoylation of mutant HTT, leading to increased mutant HTT inclusion formation and toxicity. The interaction between HIP14 and HTT goes beyond that of only an enzyme–substrate interaction as HTT is essential for the full enzymatic activity of HIP14. It is important to further understand and characterize the interactions of HTT with HIP14 and HIP14L to guide future efforts to target and enhance this interaction and increase enzyme activity to remediate palmitoylation of HTT and their substrates, as well as to understand the relationship between the three proteins. HIP14 and HIP14L have been previously shown to interact with HTT amino acids 1–548. Here the interaction of HIP14 and HIP14L with N- and C-terminal HTT 1–548 deletion mutations was assessed. We show that HTT amino acids 1–548 were sufficient for full interaction of HTT with HIP14 and HIP14L, but partial interaction was also possible with HTT 1–427 and HTT 224–548. To further characterize the binding domain we assessed the interaction of HIP14-GFP and HIP14L-GFP with 15Q HTT 1-548Δ257-315. Both enzymes showed reduced but not abolished interaction with 15Q HTT 1-548Δ257-315. This suggests that two potential binding domains exist, one around residues 224 and the other around 427, for the PAT enzymes HIP14 and HIP14L.
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Affiliation(s)
- Shaun S. Sanders
- Department of Medical Genetics and Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Katherine K. N. Mui
- Department of Medical Genetics and Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Liza M. Sutton
- Department of Medical Genetics and Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Michael R. Hayden
- Department of Medical Genetics and Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
- * E-mail:
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Abstract
Alpha-solenoids are flexible protein structural domains formed by ensembles of alpha-helical repeats (Armadillo and HEAT repeats among others). While homology can be used to detect many of these repeats, some alpha-solenoids have very little sequence homology to proteins of known structure and we expect that many remain undetected. We previously developed a method for detection of alpha-helical repeats based on a neural network trained on a dataset of protein structures. Here we improved the detection algorithm and updated the training dataset using recently solved structures of alpha-solenoids. Unexpectedly, we identified occurrences of alpha-solenoids in solved protein structures that escaped attention, for example within the core of the catalytic subunit of PI3KC. Our results expand the current set of known alpha-solenoids. Application of our tool to the protein universe allowed us to detect their significant enrichment in proteins interacting with many proteins, confirming that alpha-solenoids are generally involved in protein-protein interactions. We then studied the taxonomic distribution of alpha-solenoids to discuss an evolutionary scenario for the emergence of this type of domain, speculating that alpha-solenoids have emerged in multiple taxa in independent events by convergent evolution. We observe a higher rate of alpha-solenoids in eukaryotic genomes and in some prokaryotic families, such as Cyanobacteria and Planctomycetes, which could be associated to increased cellular complexity. The method is available at http://cbdm.mdc-berlin.de/~ard2/.
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38
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A Y2H-seq approach defines the human protein methyltransferase interactome. Nat Methods 2013; 10:339-42. [PMID: 23455924 DOI: 10.1038/nmeth.2397] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Accepted: 01/15/2013] [Indexed: 11/09/2022]
Abstract
To accelerate high-density interactome mapping, we developed a yeast two-hybrid interaction screening approach involving short-read second-generation sequencing (Y2H-seq) with improved sensitivity and a quantitative scoring readout allowing rapid interaction validation. We applied Y2H-seq to investigate enzymes involved in protein methylation, a largely unexplored post-translational modification. The reported network of 523 interactions involving 22 methyltransferases or demethylases is comprehensively annotated and validated through coimmunoprecipitation experiments and defines previously undiscovered cellular roles of nonhistone protein methylation.
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39
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Suter B, Fontaine JF, Yildirimman R, Raskó T, Schaefer MH, Rasche A, Porras P, Vázquez-Álvarez BM, Russ J, Rau K, Foulle R, Zenkner M, Saar K, Herwig R, Andrade-Navarro MA, Wanker EE. Development and application of a DNA microarray-based yeast two-hybrid system. Nucleic Acids Res 2012; 41:1496-507. [PMID: 23275563 PMCID: PMC3561971 DOI: 10.1093/nar/gks1329] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The yeast two-hybrid (Y2H) system is the most widely applied methodology for systematic protein–protein interaction (PPI) screening and the generation of comprehensive interaction networks. We developed a novel Y2H interaction screening procedure using DNA microarrays for high-throughput quantitative PPI detection. Applying a global pooling and selection scheme to a large collection of human open reading frames, proof-of-principle Y2H interaction screens were performed for the human neurodegenerative disease proteins huntingtin and ataxin-1. Using systematic controls for unspecific Y2H results and quantitative benchmarking, we identified and scored a large number of known and novel partner proteins for both huntingtin and ataxin-1. Moreover, we show that this parallelized screening procedure and the global inspection of Y2H interaction data are uniquely suited to define specific PPI patterns and their alteration by disease-causing mutations in huntingtin and ataxin-1. This approach takes advantage of the specificity and flexibility of DNA microarrays and of the existence of solid-related statistical methods for the analysis of DNA microarray data, and allows a quantitative approach toward interaction screens in human and in model organisms.
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Affiliation(s)
- Bernhard Suter
- Max Delbrueck Center for Molecular Medicine, Berlin 13125, Germany.
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PROSPER: an integrated feature-based tool for predicting protease substrate cleavage sites. PLoS One 2012; 7:e50300. [PMID: 23209700 PMCID: PMC3510211 DOI: 10.1371/journal.pone.0050300] [Citation(s) in RCA: 222] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Accepted: 10/18/2012] [Indexed: 12/04/2022] Open
Abstract
The ability to catalytically cleave protein substrates after synthesis is fundamental for all forms of life. Accordingly, site-specific proteolysis is one of the most important post-translational modifications. The key to understanding the physiological role of a protease is to identify its natural substrate(s). Knowledge of the substrate specificity of a protease can dramatically improve our ability to predict its target protein substrates, but this information must be utilized in an effective manner in order to efficiently identify protein substrates by in silico approaches. To address this problem, we present PROSPER, an integrated feature-based server for in silico identification of protease substrates and their cleavage sites for twenty-four different proteases. PROSPER utilizes established specificity information for these proteases (derived from the MEROPS database) with a machine learning approach to predict protease cleavage sites by using different, but complementary sequence and structure characteristics. Features used by PROSPER include local amino acid sequence profile, predicted secondary structure, solvent accessibility and predicted native disorder. Thus, for proteases with known amino acid specificity, PROSPER provides a convenient, pre-prepared tool for use in identifying protein substrates for the enzymes. Systematic prediction analysis for the twenty-four proteases thus far included in the database revealed that the features we have included in the tool strongly improve performance in terms of cleavage site prediction, as evidenced by their contribution to performance improvement in terms of identifying known cleavage sites in substrates for these enzymes. In comparison with two state-of-the-art prediction tools, PoPS and SitePrediction, PROSPER achieves greater accuracy and coverage. To our knowledge, PROSPER is the first comprehensive server capable of predicting cleavage sites of multiple proteases within a single substrate sequence using machine learning techniques. It is freely available at http://lightning.med.monash.edu.au/PROSPER/.
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Petrakis S, Raskó T, Russ J, Friedrich RP, Stroedicke M, Riechers SP, Muehlenberg K, Möller A, Reinhardt A, Vinayagam A, Schaefer MH, Boutros M, Tricoire H, Andrade-Navarro MA, Wanker EE. Identification of human proteins that modify misfolding and proteotoxicity of pathogenic ataxin-1. PLoS Genet 2012; 8:e1002897. [PMID: 22916034 PMCID: PMC3420947 DOI: 10.1371/journal.pgen.1002897] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Accepted: 07/02/2012] [Indexed: 02/06/2023] Open
Abstract
Proteins with long, pathogenic polyglutamine (polyQ) sequences have an enhanced propensity to spontaneously misfold and self-assemble into insoluble protein aggregates. Here, we have identified 21 human proteins that influence polyQ-induced ataxin-1 misfolding and proteotoxicity in cell model systems. By analyzing the protein sequences of these modifiers, we discovered a recurrent presence of coiled-coil (CC) domains in ataxin-1 toxicity enhancers, while such domains were not present in suppressors. This suggests that CC domains contribute to the aggregation- and toxicity-promoting effects of modifiers in mammalian cells. We found that the ataxin-1-interacting protein MED15, computationally predicted to possess an N-terminal CC domain, enhances spontaneous ataxin-1 aggregation in cell-based assays, while no such effect was observed with the truncated protein MED15ΔCC, lacking such a domain. Studies with recombinant proteins confirmed these results and demonstrated that the N-terminal CC domain of MED15 (MED15CC) per se is sufficient to promote spontaneous ataxin-1 aggregation in vitro. Moreover, we observed that a hybrid Pum1 protein harboring the MED15CC domain promotes ataxin-1 aggregation in cell model systems. In strong contrast, wild-type Pum1 lacking a CC domain did not stimulate ataxin-1 polymerization. These results suggest that proteins with CC domains are potent enhancers of polyQ-mediated protein misfolding and aggregation in vitro and in vivo.
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Affiliation(s)
- Spyros Petrakis
- Neuroproteomics, Max Delbrueck Center for Molecular Medicine, Berlin, Germany
| | - Tamás Raskó
- Neuroproteomics, Max Delbrueck Center for Molecular Medicine, Berlin, Germany
| | - Jenny Russ
- Neuroproteomics, Max Delbrueck Center for Molecular Medicine, Berlin, Germany
| | - Ralf P. Friedrich
- Neuroproteomics, Max Delbrueck Center for Molecular Medicine, Berlin, Germany
| | - Martin Stroedicke
- Neuroproteomics, Max Delbrueck Center for Molecular Medicine, Berlin, Germany
| | | | - Katja Muehlenberg
- Neuroproteomics, Max Delbrueck Center for Molecular Medicine, Berlin, Germany
| | - Angeli Möller
- Neuroproteomics, Max Delbrueck Center for Molecular Medicine, Berlin, Germany
| | - Anita Reinhardt
- Unité BFA (EAC 7059), Université Paris Diderot-Paris7/CNRS, Paris, France
| | | | - Martin H. Schaefer
- Computational Biology and Data Mining, Max Delbrueck Center for Molecular Medicine, Berlin, Germany
| | - Michael Boutros
- Division of Signaling and Functional Genomics, German Cancer Research Center, Heidelberg, Germany
| | - Hervé Tricoire
- Unité BFA (EAC 7059), Université Paris Diderot-Paris7/CNRS, Paris, France
| | | | - Erich E. Wanker
- Neuroproteomics, Max Delbrueck Center for Molecular Medicine, Berlin, Germany
- * E-mail:
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Remeseiro S, Cuadrado A, Carretero M, Martínez P, Drosopoulos WC, Cañamero M, Schildkraut CL, Blasco MA, Losada A. Cohesin-SA1 deficiency drives aneuploidy and tumourigenesis in mice due to impaired replication of telomeres. EMBO J 2012; 31:2076-89. [PMID: 22415365 PMCID: PMC3343459 DOI: 10.1038/emboj.2012.11] [Citation(s) in RCA: 138] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Accepted: 01/09/2012] [Indexed: 01/12/2023] Open
Abstract
Cohesin is a protein complex originally identified for its role in sister chromatid cohesion, although increasing evidence portrays it also as a major organizer of interphase chromatin. Vertebrate cohesin consists of Smc1, Smc3, Rad21/Scc1 and either stromal antigen 1 (SA1) or SA2. To explore the functional specificity of these two versions of cohesin and their relevance for embryonic development and cancer, we generated a mouse model deficient for SA1. Complete ablation of SA1 results in embryonic lethality, while heterozygous animals have shorter lifespan and earlier onset of tumourigenesis. SA1-null mouse embryonic fibroblasts show decreased proliferation and increased aneuploidy as a result of chromosome segregation defects. These defects are not caused by impaired centromeric cohesion, which depends on cohesin-SA2. Instead, they arise from defective telomere replication, which requires cohesion mediated specifically by cohesin-SA1. We propose a novel mechanism for aneuploidy generation that involves impaired telomere replication upon loss of cohesin-SA1, with clear implications in tumourigenesis.
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Affiliation(s)
- Silvia Remeseiro
- Chromosome Dynamics Group, Molecular Oncology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Ana Cuadrado
- Chromosome Dynamics Group, Molecular Oncology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - María Carretero
- Chromosome Dynamics Group, Molecular Oncology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Paula Martínez
- Telomeres and Telomerase Group, Molecular Oncology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | | | - Marta Cañamero
- Comparative Pathology Unit, Biotechnology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Carl L Schildkraut
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - María A Blasco
- Telomeres and Telomerase Group, Molecular Oncology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Ana Losada
- Chromosome Dynamics Group, Molecular Oncology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
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Lo Sardo V, Zuccato C, Gaudenzi G, Vitali B, Ramos C, Tartari M, Myre MA, Walker JA, Pistocchi A, Conti L, Valenza M, Drung B, Schmidt B, Gusella J, Zeitlin S, Cotelli F, Cattaneo E. An evolutionary recent neuroepithelial cell adhesion function of huntingtin implicates ADAM10-Ncadherin. Nat Neurosci 2012; 15:713-21. [PMID: 22466506 DOI: 10.1038/nn.3080] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Accepted: 03/05/2012] [Indexed: 02/06/2023]
Abstract
The Huntington's disease gene product, huntingtin, is indispensable for neural tube formation, but its role is obscure. We studied neurulation in htt-null embryonic stem cells and htt-morpholino zebrafish embryos and found a previously unknown, evolutionarily recent function for this ancient protein. We found that htt was essential for homotypic interactions between neuroepithelial cells; it permitted neurulation and rosette formation by regulating metalloprotease ADAM10 activity and Ncadherin cleavage. This function was embedded in the N terminus of htt and was phenocopied by treatment of htt knockdown zebrafish with an ADAM10 inhibitor. Notably, in htt-null cells, reversion of the rosetteless phenotype occurred only with expression of evolutionarily recent htt heterologues from deuterostome organisms. Conversely, all of the heterologues that we tested, including htt from Drosophila melanogaster and Dictyostelium discoideum, exhibited anti-apoptotic activity. Thus, anti-apoptosis may have been one of htt’s ancestral function(s), but, in deuterostomes, htt evolved to acquire a unique regulatory activity for controlling neural adhesion via ADAM10-Ncadherin, with implications for brain evolution and development.
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Affiliation(s)
- Valentina Lo Sardo
- Department of Pharmacological Sciences and Centre for Stem Cell Research, Università degli Studi di Milano, Milano, Italy
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Pellegrini M, Renda ME, Vecchio A. Ab initio detection of fuzzy amino acid tandem repeats in protein sequences. BMC Bioinformatics 2012; 13 Suppl 3:S8. [PMID: 22536906 PMCID: PMC3402919 DOI: 10.1186/1471-2105-13-s3-s8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Tandem repetitions within protein amino acid sequences often correspond to regular secondary structures and form multi-repeat 3D assemblies of varied size and function. Developing internal repetitions is one of the evolutionary mechanisms that proteins employ to adapt their structure and function under evolutionary pressure. While there is keen interest in understanding such phenomena, detection of repeating structures based only on sequence analysis is considered an arduous task, since structure and function is often preserved even under considerable sequence divergence (fuzzy tandem repeats). RESULTS In this paper we present PTRStalker, a new algorithm for ab-initio detection of fuzzy tandem repeats in protein amino acid sequences. In the reported results we show that by feeding PTRStalker with amino acid sequences from the UniProtKB/Swiss-Prot database we detect novel tandemly repeated structures not captured by other state-of-the-art tools. Experiments with membrane proteins indicate that PTRStalker can detect global symmetries in the primary structure which are then reflected in the tertiary structure. CONCLUSIONS PTRStalker is able to detect fuzzy tandem repeating structures in protein sequences, with performance beyond the current state-of-the art. Such a tool may be a valuable support to investigating protein structural properties when tertiary X-ray data is not available.
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Affiliation(s)
- Marco Pellegrini
- Istituto di Informatica e Telematica, CNR - Consiglio Nazionale delle Ricerche, Pisa I-56124, Italy.
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Ganglioside GM1 induces phosphorylation of mutant huntingtin and restores normal motor behavior in Huntington disease mice. Proc Natl Acad Sci U S A 2012; 109:3528-33. [PMID: 22331905 DOI: 10.1073/pnas.1114502109] [Citation(s) in RCA: 121] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Huntington disease (HD) is a progressive neurodegenerative monogenic disorder caused by expansion of a polyglutamine stretch in the huntingtin (Htt) protein. Mutant huntingtin triggers neural dysfunction and death, mainly in the corpus striatum and cerebral cortex, resulting in pathognomonic motor symptoms, as well as cognitive and psychiatric decline. Currently, there is no effective treatment for HD. We report that intraventricular infusion of ganglioside GM1 induces phosphorylation of mutant huntingtin at specific serine amino acid residues that attenuate huntingtin toxicity, and restores normal motor function in already symptomatic HD mice. Thus, our studies have identified a potential therapy for HD that targets a posttranslational modification of mutant huntingtin with critical effects on disease pathogenesis.
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Wetzel R. Physical chemistry of polyglutamine: intriguing tales of a monotonous sequence. J Mol Biol 2012; 421:466-90. [PMID: 22306404 DOI: 10.1016/j.jmb.2012.01.030] [Citation(s) in RCA: 128] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Accepted: 01/18/2012] [Indexed: 01/08/2023]
Abstract
Polyglutamine (polyQ) sequences of unknown normal function are present in a significant number of proteins, and their repeat expansion is associated with a number of genetic neurodegenerative diseases. PolyQ solution structure and properties are important not only because of the normal and abnormal biology associated with these sequences but also because they represent an interesting case of a biologically relevant homopolymer. As the common thread in expanded polyQ repeat diseases, it is important to understand the structure and properties of simple polyQ sequences. At the same time, experience has shown that sequences attached to polyQ, whether in artificial constructs or in disease proteins, can influence structure and properties. The two major contenders for the molecular source of the neurotoxicity implicit in polyQ expansion within disease proteins are a populated toxic conformation in the monomer ensemble and a toxic aggregated species. This review summarizes experimental and computational studies on the solution structure and aggregation properties of both simple and complex polyQ sequences, and their repeat-length dependence. As a representative of complex polyQ proteins, the behavior of huntingtin N-terminal fragments, such as exon-1, receives special attention.
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Affiliation(s)
- Ronald Wetzel
- Department of Structural Biology and Pittsburgh Institute for Neurodegenerative Disease, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA.
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Domains of Tra1 important for activator recruitment and transcription coactivator functions of SAGA and NuA4 complexes. Mol Cell Biol 2010; 31:818-31. [PMID: 21149579 DOI: 10.1128/mcb.00687-10] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The Tra1 protein is a direct transcription activator target that is essential for coactivator function of both the SAGA and NuA4 histone acetyltransferase (HAT) complexes. The ∼400-kDa Saccharomyces cerevisiae Tra1 polypeptide and its human counterpart TRRAP contain 67 or 68 tandem α-helical HEAT and TPR protein repeats that extend from the N terminus to the conserved yet catalytically inactive phosphatidylinositol 3-kinase (PI3K) domain. We generated a series of mutations spanning the length of the protein and assayed for defects in transcription, coactivator recruitment, and histone acetylation at SAGA- and NuA4-dependent genes. Inviable TRA1 mutants all showed defects in SAGA and NuA4 complex stability, suggesting that similar surfaces of Tra1 mediate assembly of these two very different coactivator complexes. Nearly all of the viable Tra1 mutants showed transcription defects that fell into one of three classes: (i) defective recruitment to promoters, (ii) reduced stability of the SAGA and NuA4 HAT modules, or (iii) normal recruitment of Tra1-associated subunits but reduced HAT activity in vivo. Our results show that Tra1 recruitment at Gcn4-dependent and Rap1-dependent promoters requires the same regions of Tra1 and that separate regions of Tra1 contribute to the HAT activity and stability of the SAGA and NuA4 HAT modules.
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Huntingtin Is Required for Mitotic Spindle Orientation and Mammalian Neurogenesis. Neuron 2010; 67:392-406. [DOI: 10.1016/j.neuron.2010.06.027] [Citation(s) in RCA: 194] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/17/2010] [Indexed: 01/06/2023]
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Zuccato C, Valenza M, Cattaneo E. Molecular Mechanisms and Potential Therapeutical Targets in Huntington's Disease. Physiol Rev 2010; 90:905-81. [DOI: 10.1152/physrev.00041.2009] [Citation(s) in RCA: 626] [Impact Index Per Article: 44.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Huntington's disease (HD) is a neurodegenerative disorder caused by a CAG repeat expansion in the gene encoding for huntingtin protein. A lot has been learned about this disease since its first description in 1872 and the identification of its causative gene and mutation in 1993. We now know that the disease is characterized by several molecular and cellular abnormalities whose precise timing and relative roles in pathogenesis have yet to be understood. HD is triggered by the mutant protein, and both gain-of-function (of the mutant protein) and loss-of-function (of the normal protein) mechanisms are involved. Here we review the data that describe the emergence of the ancient huntingtin gene and of the polyglutamine trait during the last 800 million years of evolution. We focus on the known functions of wild-type huntingtin that are fundamental for the survival and functioning of the brain neurons that predominantly degenerate in HD. We summarize data indicating how the loss of these beneficial activities reduces the ability of these neurons to survive. We also review the different mechanisms by which the mutation in huntingtin causes toxicity. This may arise both from cell-autonomous processes and dysfunction of neuronal circuitries. We then focus on novel therapeutical targets and pathways and on the attractive option to counteract HD at its primary source, i.e., by blocking the production of the mutant protein. Strategies and technologies used to screen for candidate HD biomarkers and their potential application are presented. Furthermore, we discuss the opportunities offered by intracerebral cell transplantation and the likely need for these multiple routes into therapies to converge at some point as, ideally, one would wish to stop the disease process and, at the same time, possibly replace the damaged neurons.
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Affiliation(s)
- Chiara Zuccato
- Department of Pharmacological Sciences and Centre for Stem Cell Research, Università degli Studi di Milano, Milan, Italy
| | - Marta Valenza
- Department of Pharmacological Sciences and Centre for Stem Cell Research, Università degli Studi di Milano, Milan, Italy
| | - Elena Cattaneo
- Department of Pharmacological Sciences and Centre for Stem Cell Research, Università degli Studi di Milano, Milan, Italy
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Pardo R, Molina-Calavita M, Poizat G, Keryer G, Humbert S, Saudou F. pARIS-htt: an optimised expression platform to study huntingtin reveals functional domains required for vesicular trafficking. Mol Brain 2010; 3:17. [PMID: 20515468 PMCID: PMC2887845 DOI: 10.1186/1756-6606-3-17] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2010] [Accepted: 06/01/2010] [Indexed: 01/02/2023] Open
Abstract
Background Huntingtin (htt) is a multi-domain protein of 350 kDa that is mutated in Huntington's disease (HD) but whose function is yet to be fully understood. This absence of information is due in part to the difficulty of manipulating large DNA fragments by using conventional molecular cloning techniques. Consequently, few studies have addressed the cellular function(s) of full-length htt and its dysfunction(s) associated with the disease. Results We describe a flexible synthetic vector encoding full-length htt called pARIS-htt (Adaptable, RNAi Insensitive &Synthetic). It includes synthetic cDNA coding for full-length human htt modified so that: 1) it is improved for codon usage, 2) it is insensitive to four different siRNAs allowing gene replacement studies, 3) it contains unique restriction sites (URSs) dispersed throughout the entire sequence without modifying the translated amino acid sequence, 4) it contains multiple cloning sites at the N and C-ter ends and 5) it is Gateway compatible. These modifications facilitate mutagenesis, tagging and cloning into diverse expression plasmids. Htt regulates dynein/dynactin-dependent trafficking of vesicles, such as brain-derived neurotrophic factor (BDNF)-containing vesicles, and of organelles, including reforming and maintenance of the Golgi near the cell centre. We used tests of these trafficking functions to validate various pARIS-htt constructs. We demonstrated, after silencing of endogenous htt, that full-length htt expressed from pARIS-htt rescues Golgi apparatus reformation following reversible microtubule disruption. A mutant form of htt that contains a 100Q expansion and a htt form devoid of either HAP1 or dynein interaction domains are both unable to rescue loss of endogenous htt. These mutants have also an impaired capacity to promote BDNF vesicular trafficking in neuronal cells. Conclusion We report the validation of a synthetic gene encoding full-length htt protein that will facilitate analyses of its structure/function. This may help provide relevant information about the cellular dysfunctions operating during the disease. As proof of principle, we show that either polyQ expansion or deletion of key interacting domains within full-length htt protein impairs its function in transport indicating that HD mutation induces defects on intrinsic properties of the protein and further demonstrating the importance of studying htt in its full-length context.
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