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Patil PR, Burroughs AM, Misra M, Cerullo F, Costas-Insua C, Hung HC, Dikic I, Aravind L, Joazeiro CAP. Mechanism and evolutionary origins of alanine-tail C-degron recognition by E3 ligases Pirh2 and CRL2-KLHDC10. Cell Rep 2023; 42:113100. [PMID: 37676773 PMCID: PMC10591846 DOI: 10.1016/j.celrep.2023.113100] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 07/11/2023] [Accepted: 08/22/2023] [Indexed: 09/09/2023] Open
Abstract
In ribosome-associated quality control (RQC), nascent polypeptides produced by interrupted translation are modified with C-terminal polyalanine tails ("Ala-tails") that function outside ribosomes to induce ubiquitylation by E3 ligases Pirh2 (p53-induced RING-H2 domain-containing) or CRL2 (Cullin-2 RING ligase2)-KLHDC10. Here, we investigate the molecular basis of Ala-tail function using biochemical and in silico approaches. We show that Pirh2 and KLHDC10 directly bind to Ala-tails and that structural predictions identify candidate Ala-tail-binding sites, which we experimentally validate. The degron-binding pockets and specific pocket residues implicated in Ala-tail recognition are conserved among Pirh2 and KLHDC10 homologs, suggesting that an important function of these ligases across eukaryotes is in targeting Ala-tailed substrates. Moreover, we establish that the two Ala-tail-binding pockets have convergently evolved, either from an ancient module of bacterial provenance (Pirh2) or via tinkering of a widespread C-degron-recognition element (KLHDC10). These results shed light on the recognition of a simple degron sequence and the evolution of Ala-tail proteolytic signaling.
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Affiliation(s)
- Pratik Rajendra Patil
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH-Alliance, 69120 Heidelberg, Germany
| | - A Maxwell Burroughs
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Mohit Misra
- Institute of Biochemistry II, Goethe University Faculty of Medicine, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Max-von-Laue-Strasse 15, 60438 Frankfurt am Main, Germany
| | - Federico Cerullo
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH-Alliance, 69120 Heidelberg, Germany
| | - Carlos Costas-Insua
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH-Alliance, 69120 Heidelberg, Germany
| | - Hao-Chih Hung
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH-Alliance, 69120 Heidelberg, Germany
| | - Ivan Dikic
- Institute of Biochemistry II, Goethe University Faculty of Medicine, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Max-von-Laue-Strasse 15, 60438 Frankfurt am Main, Germany
| | - L Aravind
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Claudio A P Joazeiro
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH-Alliance, 69120 Heidelberg, Germany; Department of Molecular Medicine, UF Scripps Biomedical Research, Jupiter, FL 33458, USA.
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Nunes EAC, da Silva MC, Cardoso MH, Preza SLE, de Oliveira LS, Frihling BEF, Charneau SO, Grellier P, Franco OL, Migliolo L. Anti-Protozoan Activities of Polar Fish-Derived Polyalanine Synthetic Peptides. Mar Drugs 2023; 21:434. [PMID: 37623715 PMCID: PMC10456387 DOI: 10.3390/md21080434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 07/14/2023] [Accepted: 07/19/2023] [Indexed: 08/26/2023] Open
Abstract
Chagas disease, sleeping sickness and malaria are infectious diseases caused by protozoan parasites that kill millions of people worldwide. Here, we performed in vitro assays of Pa-MAP, Pa-MAP1.9, and Pa-MAP2 synthetic polyalanine peptides derived from the polar fish Pleuronectes americanus toward Trypanosoma cruzi, T. brucei gambiense and Plasmodium falciparum activities. We demonstrated that the peptides Pa-MAP1.9 and Pa-MAP2 were effective to inhibit T. brucei growth. In addition, structural analyses using molecular dynamics (MD) studies showed that Pa-MAP2 penetrates deeper into the membrane and interacts more with phospholipids than Pa-MAP1.9, corroborating the previous in vitro results showing that Pa-MAP1.9 acts within the cell, while Pa-MAP2 acts via membrane lysis. In conclusion, polyalanine Pa-MAP1.9 and Pa-MAP2 presented activity against bloodstream forms of T. b. gambiense, thus encouraging further studies on the application of these peptides as a treatment for sleeping sickness.
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Affiliation(s)
| | - Maria Cláudia da Silva
- S-Inova Biotech, Graduate Program in Biotechnology, Dom Bosco Catholic University, Campo Grande 79117-900, Brazil
- Department of Biochemistry and Immunology, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Sao Paulo 14040-900, Brazil
- Laboratory of Research in Virology and Immunology, Institute of Biological and Health Sciences, Federal University of Alagoas, Maceio 57020-600, Brazil
| | - Marlon Henrique Cardoso
- S-Inova Biotech, Graduate Program in Biotechnology, Dom Bosco Catholic University, Campo Grande 79117-900, Brazil
- Center for Proteomics and Biochemical Analysis, Catholic University of Brasília, Brasilia 71966-700, Brazil
| | | | - Lucas Silva de Oliveira
- Laboratory of Biochemistry and Protein Chemistry, Department of Cell Biology, Institute of Biological Sciences, University of Brasília, Brasilia 73345-010, Brazil
- UMR 7245 Molécules de Communication et Adaptation des Micro-Organismes, Muséum National d'Histoire Naturelle, CNRS, 75005 Paris, France
- Graduate Program in Molecular Pathology, University of Brasilia, Brasilia 73345-010, Brazil
| | | | - Sébastien Olivier Charneau
- Laboratory of Biochemistry and Protein Chemistry, Department of Cell Biology, Institute of Biological Sciences, University of Brasília, Brasilia 73345-010, Brazil
- Graduate Program in Molecular Pathology, University of Brasilia, Brasilia 73345-010, Brazil
| | - Philippe Grellier
- UMR 7245 Molécules de Communication et Adaptation des Micro-Organismes, Muséum National d'Histoire Naturelle, CNRS, 75005 Paris, France
| | - Octávio Luiz Franco
- S-Inova Biotech, Graduate Program in Biotechnology, Dom Bosco Catholic University, Campo Grande 79117-900, Brazil
- Center for Proteomics and Biochemical Analysis, Catholic University of Brasília, Brasilia 71966-700, Brazil
| | - Ludovico Migliolo
- Postgraduate Program in Biochemistry, Federal University of Rio Grande do Norte, Natal 59078-900, Brazil
- S-Inova Biotech, Graduate Program in Biotechnology, Dom Bosco Catholic University, Campo Grande 79117-900, Brazil
- Postgraduate Program in Cellular and Molecular Biology, Federal University of Paraíba, João Pessoa 58051-900, Brazil
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3
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Takahashi Y, Morimoto N, Nada T, Morimoto M, Eura N, Minami N, Nishino I. A Case of Oculopharyngeal Muscular Dystrophy Caused by a Novel PABPN1 c.34G > T (p.Gly12Trp) Point Mutation without Polyalanine Expansion. J Neuromuscul Dis 2023; 10:459-463. [PMID: 36847015 DOI: 10.3233/jnd-221669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Immediately after the initial methionine codon, the PABPN1 gene encodes a stretch of 10 alanines, 1 glycine, and 2 alanines. Oculopharyngeal muscular dystrophy (OPMD) is caused by the expansion of the first 10 alanine stretches. The only exception is the missense mutation of glycine at the 12th residue into alanine, which elongates the stretch to 13 alanines by connecting the first and second stretch with the addition of one alanine in between, indicating that the expansion or elongation of the alanine stretch results in OPMD. We report a 77-year-old man with the novel missense mutation c.34G > T (p.Gly12Trp) in PABPN1 gene whose clinicopathological findings were compatible with OPMD. He presented with slowly progressive bilateral ptosis, dysphagia, and symmetrical proximal dominant muscle weakness. Magnetic resonance imaging revealed selective fat replacement of the tongue, bilateral adductor magnus, and soleus muscles. Immunohistochemistry studies of the muscle biopsy sample revealed PABPN1-posibive aggregates in the myonuclei which have been reported to be specific to OPMD. This is the first OPMD case caused by neither the expansion nor the elongation of alanine stretch. The present case suggests that OPMD may be caused not only by triplet repeats but also by point mutations.
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Affiliation(s)
- Yoshiaki Takahashi
- Department of Neurology, Kagawa Prefectural Central Hospital, Kagawa, Japan
| | - Nobutoshi Morimoto
- Department of Neurology, Kagawa Prefectural Central Hospital, Kagawa, Japan
| | - Tomoaki Nada
- Department of Neurology, Kagawa Prefectural Central Hospital, Kagawa, Japan
| | - Mizuki Morimoto
- Department of Neurology, Kagawa Prefectural Central Hospital, Kagawa, Japan
| | - Nobuyuki Eura
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Narihiro Minami
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Ichizo Nishino
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
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4
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Loureiro JR, Castro AF, Figueiredo AS, Silveira I. Molecular Mechanisms in Pentanucleotide Repeat Diseases. Cells 2022; 11:cells11020205. [PMID: 35053321 PMCID: PMC8773600 DOI: 10.3390/cells11020205] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 01/04/2022] [Accepted: 01/05/2022] [Indexed: 02/01/2023] Open
Abstract
The number of neurodegenerative diseases resulting from repeat expansion has increased extraordinarily in recent years. In several of these pathologies, the repeat can be transcribed in RNA from both DNA strands producing, at least, one toxic RNA repeat that causes neurodegeneration by a complex mechanism. Recently, seven diseases have been found caused by a novel intronic pentanucleotide repeat in distinct genes encoding proteins highly expressed in the cerebellum. These disorders are clinically heterogeneous being characterized by impaired motor function, resulting from ataxia or epilepsy. The role that apparently normal proteins from these mutant genes play in these pathologies is not known. However, recent advances in previously known spinocerebellar ataxias originated by abnormal non-coding pentanucleotide repeats point to a gain of a toxic function by the pathogenic repeat-containing RNA that abnormally forms nuclear foci with RNA-binding proteins. In cells, RNA foci have been shown to be formed by phase separation. Moreover, the field of repeat expansions has lately achieved an extraordinary progress with the discovery that RNA repeats, polyglutamine, and polyalanine proteins are crucial for the formation of nuclear membraneless organelles by phase separation, which is perturbed when they are expanded. This review will cover the amazing advances on repeat diseases.
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Affiliation(s)
- Joana R. Loureiro
- Genetics of Cognitive Dysfunction Laboratory, i3S- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; (J.R.L.); (A.F.C.); (A.S.F.)
- Institute for Molecular and Cell Biology, Universidade do Porto, 4200-135 Porto, Portugal
| | - Ana F. Castro
- Genetics of Cognitive Dysfunction Laboratory, i3S- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; (J.R.L.); (A.F.C.); (A.S.F.)
- Institute for Molecular and Cell Biology, Universidade do Porto, 4200-135 Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, 4050-313 Porto, Portugal
| | - Ana S. Figueiredo
- Genetics of Cognitive Dysfunction Laboratory, i3S- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; (J.R.L.); (A.F.C.); (A.S.F.)
- Institute for Molecular and Cell Biology, Universidade do Porto, 4200-135 Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, 4050-313 Porto, Portugal
| | - Isabel Silveira
- Genetics of Cognitive Dysfunction Laboratory, i3S- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; (J.R.L.); (A.F.C.); (A.S.F.)
- Institute for Molecular and Cell Biology, Universidade do Porto, 4200-135 Porto, Portugal
- Correspondence: ; Tel.: +351-2240-8800
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5
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Zhao S, Ye X, Wu M, Ruan J, Wang X, Tang X, Zhong B. Recombinant Silk Proteins with Additional Polyalanine Have Excellent Mechanical Properties. Int J Mol Sci 2021; 22:ijms22041513. [PMID: 33546270 PMCID: PMC7913374 DOI: 10.3390/ijms22041513] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Revised: 01/22/2021] [Accepted: 01/28/2021] [Indexed: 11/16/2022] Open
Abstract
This paper explores the structures of exogenous protein molecules that can effectively improve the mechanical properties of silkworm silk. Several transgenic vectors fused with the silkworm fibroin light chain and type 3 repeats in different multiples of the ampullate dragline silk protein 1 (MaSp1) from black widow spider with different lengths of the polyalanine motifs were constructed for this study. Transgenic silkworms were successfully obtained by piggyBac-mediated microinjection. Molecular detection showed that foreign proteins were successfully secreted and contained within the cocoon shells. According to the prediction of PONDR® VSL2 and PONDR® VL-XT, the type 3 repeats and the polyalanine motif of the MaSp1 protein were amorphous. The results of FTIR analysis showed that the content of β-sheets in the silk of transgenic silkworms engineered with transgenic vectors with additional polyalanine was significantly higher than that of wild-type silkworm silk. Additionally, silk with a higher β-sheet content had better fracture strength and Young’s modulus. The mechanical properties of silk with longer chains of exogenous proteins were improved. In general, our results provide theoretical guidance and technical support for the large-scale production of excellent bionic silk.
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6
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Chen TC, Huang JR. Musashi-1: An Example of How Polyalanine Tracts Contribute to Self-Association in the Intrinsically Disordered Regions of RNA-Binding Proteins. Int J Mol Sci 2020; 21:E2289. [PMID: 32225071 DOI: 10.3390/ijms21072289] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 03/20/2020] [Accepted: 03/24/2020] [Indexed: 12/19/2022] Open
Abstract
RNA-binding proteins (RBPs) have intrinsically disordered regions (IDRs) whose biophysical properties have yet to be explored to the same extent as those of the folded RNA interacting domains. These IDRs are essential to the formation of biomolecular condensates, such as stress and RNA granules, but dysregulated assembly can be pathological. Because of their structural heterogeneity, IDRs are best studied by NMR spectroscopy. In this study, we used NMR spectroscopy to investigate the structural propensity and self-association of the IDR of the RBP Musashi-1. We identified two transient α-helical regions (residues ~208–218 and ~270–284 in the IDR, the latter with a polyalanine tract). Strong NMR line broadening in these regions and circular dichroism and micrography data suggest that the two α-helical elements and the hydrophobic residues in between may contribute to the formation of oligomers found in stress granules and implicated in Alzheimer’s disease. Bioinformatics analysis suggests that polyalanine stretches in the IDRs of RBPs may have evolved to promote RBP assembly.
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7
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Pelassa I, Cibelli M, Villeri V, Lilliu E, Vaglietti S, Olocco F, Ghirardi M, Montarolo PG, Corà D, Fiumara F. Compound Dynamics and Combinatorial Patterns of Amino Acid Repeats Encode a System of Evolutionary and Developmental Markers. Genome Biol Evol 2020; 11:3159-3178. [PMID: 31589292 PMCID: PMC6839033 DOI: 10.1093/gbe/evz216] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/27/2019] [Indexed: 01/05/2023] Open
Abstract
Homopolymeric amino acid repeats (AARs) like polyalanine (polyA) and polyglutamine (polyQ) in some developmental proteins (DPs) regulate certain aspects of organismal morphology and behavior, suggesting an evolutionary role for AARs as developmental "tuning knobs." It is still unclear, however, whether these are occasional protein-specific phenomena or hints at the existence of a whole AAR-based regulatory system in DPs. Using novel approaches to trace their functional and evolutionary history, we find quantitative evidence supporting a generalized, combinatorial role of AARs in developmental processes with evolutionary implications. We observe nonrandom AAR distributions and combinations in HOX and other DPs, as well as in their interactomes, defining elements of a proteome-wide combinatorial functional code whereby different AARs and their combinations appear preferentially in proteins involved in the development of specific organs/systems. Such functional associations can be either static or display detectable evolutionary dynamics. These findings suggest that progressive changes in AAR occurrence/combination, by altering embryonic development, may have contributed to taxonomic divergence, leaving detectable traces in the evolutionary history of proteomes. Consistent with this hypothesis, we find that the evolutionary trajectories of the 20 AARs in eukaryotic proteomes are highly interrelated and their individual or compound dynamics can sharply mark taxonomic boundaries, or display clock-like trends, carrying overall a strong phylogenetic signal. These findings provide quantitative evidence and an interpretive framework outlining a combinatorial system of AARs whose compound dynamics mark at the same time DP functions and evolutionary transitions.
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Affiliation(s)
- Ilaria Pelassa
- Department of Neuroscience Rita Levi Montalcini, University of Torino, Italy
| | - Marica Cibelli
- Department of Neuroscience Rita Levi Montalcini, University of Torino, Italy
| | - Veronica Villeri
- Department of Neuroscience Rita Levi Montalcini, University of Torino, Italy
| | - Elena Lilliu
- Department of Neuroscience Rita Levi Montalcini, University of Torino, Italy
| | - Serena Vaglietti
- Department of Neuroscience Rita Levi Montalcini, University of Torino, Italy
| | - Federica Olocco
- Department of Neuroscience Rita Levi Montalcini, University of Torino, Italy
| | - Mirella Ghirardi
- Department of Neuroscience Rita Levi Montalcini, University of Torino, Italy.,National Institute of Neuroscience (INN), Torino, Italy
| | - Pier Giorgio Montarolo
- Department of Neuroscience Rita Levi Montalcini, University of Torino, Italy.,National Institute of Neuroscience (INN), Torino, Italy
| | - Davide Corà
- Department of Translational Medicine, Piemonte Orientale University, Novara, Italy.,Center for Translational Research on Autoimmune and Allergic Disease (CAAD), Novara, Italy
| | - Ferdinando Fiumara
- Department of Neuroscience Rita Levi Montalcini, University of Torino, Italy.,National Institute of Neuroscience (INN), Torino, Italy
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Zhou C, Ieritano C, Hopkins WS. Augmenting Basin-Hopping With Techniques From Unsupervised Machine Learning: Applications in Spectroscopy and Ion Mobility. Front Chem 2019; 7:519. [PMID: 31440497 PMCID: PMC6693329 DOI: 10.3389/fchem.2019.00519] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 07/08/2019] [Indexed: 12/17/2022] Open
Abstract
Evolutionary algorithms such as the basin-hopping (BH) algorithm have proven to be useful for difficult non-linear optimization problems with multiple modalities and variables. Applications of these algorithms range from characterization of molecular states in statistical physics and molecular biology to geometric packing problems. A key feature of BH is the fact that one can generate a coarse-grained mapping of a potential energy surface (PES) in terms of local minima. These results can then be utilized to gain insights into molecular dynamics and thermodynamic properties. Here we describe how one can employ concepts from unsupervised machine learning to augment BH PES searches to more efficiently identify local minima and the transition states connecting them. Specifically, we introduce the concepts of similarity indices, hierarchical clustering, and multidimensional scaling to the BH methodology. These same machine learning techniques can be used as tools for interpreting and rationalizing experimental results from spectroscopic and ion mobility investigations (e.g., spectral assignment, dynamic collision cross sections). We exemplify this in two case studies: (1) assigning the infrared multiple photon dissociation spectrum of the protonated serine dimer and (2) determining the temperature-dependent collision cross-section of protonated alanine tripeptide.
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Affiliation(s)
- Ce Zhou
- Department of Chemistry, University of Waterloo, Waterloo, ON, Canada
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9
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Pelassa I, Fiumara F. Differential Occurrence of Interactions and Interaction Domains in Proteins Containing Homopolymeric Amino Acid Repeats. Front Genet 2015; 6:345. [PMID: 26734058 PMCID: PMC4683181 DOI: 10.3389/fgene.2015.00345] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 11/20/2015] [Indexed: 12/13/2022] Open
Abstract
Homopolymeric amino acids repeats (AARs), which are widespread in proteomes, have often been viewed simply as spacers between protein domains, or even as "junk" sequences with no obvious function but with a potential to cause harm upon expansion as in genetic diseases associated with polyglutamine or polyalanine expansions, including Huntington disease and cleidocranial dysplasia. A growing body of evidence indicates however that at least some AARs can form organized, functional protein structures, and can regulate protein function. In particular, certain AARs can mediate protein-protein interactions, either through homotypic AAR-AAR contacts or through heterotypic contacts with other protein domains. It is still unclear however, whether AARs may have a generalized, proteome-wide role in shaping protein-protein interaction networks. Therefore, we have undertaken here a bioinformatics screening of the human proteome and interactome in search of quantitative evidence of such a role. We first identified the sets of proteins that contain repeats of any one of the 20 amino acids, as well as control sets of proteins chosen at random in the proteome. We then analyzed the connectivity between the proteins of the AAR-containing protein sets and we compared it with that observed in the corresponding control networks. We find evidence for different degrees of connectivity in the different AAR-containing protein networks. Indeed, networks of proteins containing polyglutamine, polyglutamate, polyproline, and other AARs show significantly increased levels of connectivity, whereas networks containing polyleucine and other hydrophobic repeats show lower degrees of connectivity. Furthermore, we observed that numerous protein-protein, -nucleic acid, and -lipid interaction domains are significantly enriched in specific AAR protein groups. These findings support the notion of a generalized, combinatorial role of AARs, together with conventional protein interaction domains, in shaping the interaction networks of the human proteome, and define proteome-wide knowledge that may guide the informed biological exploration of the role of AARs in protein interactions.
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Affiliation(s)
- Ilaria Pelassa
- Department of Neuroscience, University of Torino Torino, Italy
| | - Ferdinando Fiumara
- Department of Neuroscience, University of TorinoTorino, Italy; National Institute of Neuroscience (INN)Torino, Italy
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10
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Radó-Trilla N, Arató K, Pegueroles C, Raya A, de la Luna S, Albà MM. Key Role of Amino Acid Repeat Expansions in the Functional Diversification of Duplicated Transcription Factors. Mol Biol Evol 2015; 32:2263-72. [PMID: 25931513 PMCID: PMC4540963 DOI: 10.1093/molbev/msv103] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The high regulatory complexity of vertebrates has been related to two rounds of whole genome duplication (2R-WGD) that occurred before the divergence of the major vertebrate groups. Following these events, many developmental transcription factors (TFs) were retained in multiple copies and subsequently specialized in diverse functions, whereas others reverted to their singleton state. TFs are known to be generally rich in amino acid repeats or low-complexity regions (LCRs), such as polyalanine or polyglutamine runs, which can evolve rapidly and potentially influence the transcriptional activity of the protein. Here we test the hypothesis that LCRs have played a major role in the diversification of TF gene duplicates. We find that nearly half of the TF gene families originated during the 2R-WGD contains LCRs. The number of gene duplicates with LCRs is 155 out of 550 analyzed (28%), about twice as many as the number of single copy genes with LCRs (15 out of 115, 13%). In addition, duplicated TFs preferentially accumulate certain LCR types, the most prominent of which are alanine repeats. We experimentally test the role of alanine-rich LCRs in two different TF gene families, PHOX2A/PHOX2B and LHX2/LHX9. In both cases, the presence of the alanine-rich LCR in one of the copies (PHOX2B and LHX2) significantly increases the capacity of the TF to activate transcription. Taken together, the results provide strong evidence that LCRs are important driving forces of evolutionary change in duplicated genes.
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Affiliation(s)
- Núria Radó-Trilla
- Evolutionary Genomics Group, Research Programme on Biomedical Informatics (GRIB), Hospital del Mar Research Institute (IMIM), Barcelona, Spain
| | - Krisztina Arató
- Department of Experimental and Health Sciences, Universitat Pompeu Fabra (UPF), Barcelona, Spain Centre for Genomic Regulation (CRG), Barcelona, Spain Centro de Investigación Biomèdica en Red en Enfermedades Raras (CIBERER), Barcelona, Spain
| | - Cinta Pegueroles
- Evolutionary Genomics Group, Research Programme on Biomedical Informatics (GRIB), Hospital del Mar Research Institute (IMIM), Barcelona, Spain Centre for Genomic Regulation (CRG), Barcelona, Spain
| | - Alicia Raya
- Department of Experimental and Health Sciences, Universitat Pompeu Fabra (UPF), Barcelona, Spain Centre for Genomic Regulation (CRG), Barcelona, Spain Centro de Investigación Biomèdica en Red en Enfermedades Raras (CIBERER), Barcelona, Spain
| | - Susana de la Luna
- Department of Experimental and Health Sciences, Universitat Pompeu Fabra (UPF), Barcelona, Spain Centre for Genomic Regulation (CRG), Barcelona, Spain Centro de Investigación Biomèdica en Red en Enfermedades Raras (CIBERER), Barcelona, Spain Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - M Mar Albà
- Evolutionary Genomics Group, Research Programme on Biomedical Informatics (GRIB), Hospital del Mar Research Institute (IMIM), Barcelona, Spain Department of Experimental and Health Sciences, Universitat Pompeu Fabra (UPF), Barcelona, Spain Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
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11
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Terry NA, Lee RA, Walp ER, Kaestner KH, Lee May C. Dysgenesis of enteroendocrine cells in Aristaless-Related Homeobox polyalanine expansion mutations. J Pediatr Gastroenterol Nutr 2015; 60:192-9. [PMID: 25171319 DOI: 10.1097/MPG.0000000000000542] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVES Severe congenital diarrhea occurs in approximately half of patients with Aristaless-Related Homeobox (ARX) null mutations. The cause of this diarrhea is unknown. In a mouse model of intestinal Arx deficiency, the prevalence of a subset of enteroendocrine cells is altered, leading to diarrhea. Because polyalanine expansions within the ARX protein are the most common mutations found in ARX-related disorders, we sought to characterize the enteroendocrine population in human tissue of an ARX mutation and in a mouse model of the corresponding polyalanine expansion (Arx). METHODS Immunohistochemistry and quantitative real-time polymerase chain reaction were the primary modalities used to characterize the enteroendocrine populations. Daily weights were determined for the growth curves, and Oil-Red-O staining on stool and tissue identified neutral fats. RESULTS An expansion of 7 alanines in the first polyalanine tract of both human ARX and mouse Arx altered enteroendocrine differentiation. In human tissue, cholecystokinin, glucagon-like peptide 1, and somatostatin populations were reduced, whereas the chromogranin A population was unchanged. In the mouse model, cholecystokinin and glucagon-like peptide 1 populations were also lost, although the somatostatin-expressing population was increased. The ARX protein was present in human tissue, whereas the Arx protein was degraded in the mouse intestine. CONCLUSIONS ARX/Arx is required for the specification of a subset of enteroendocrine cells in both humans and mice. Owing to protein degradation, the Arx mouse recapitulates findings of the intestinal Arx null model, but is not able to further the study of the differential effects of the ARX protein on its transcriptional targets in the intestine.
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Liu C, Ponder JW, Marshall GR. Helix stability of oligoglycine, oligoalanine, and oligo-β-alanine dodecamers reflected by hydrogen-bond persistence. Proteins 2014; 82:3043-61. [PMID: 25116421 PMCID: PMC4206583 DOI: 10.1002/prot.24665] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 08/03/2014] [Indexed: 02/03/2023]
Abstract
Helices are important structural/recognition elements in proteins and peptides. Stability and conformational differences between helices composed of α- and β-amino acids as scaffolds for mimicry of helix recognition has become a theme in medicinal chemistry. Furthermore, helices formed by β-amino acids are experimentally more stable than those formed by α-amino acids. This is paradoxical because the larger sizes of the hydrogen-bonding rings required by the extra methylene groups should lead to entropic destabilization. In this study, molecular dynamics simulations using the second-generation force field, AMOEBA (Ponder, J.W., et al., Current status of the AMOEBA polarizable force field. J Phys Chem B, 2010. 114(8): p. 2549-64.) explored the stability and hydrogen-bonding patterns of capped oligo-β-alanine, oligoalanine, and oligoglycine dodecamers in water. The MD simulations showed that oligo-β-alanine has strong acceptor+2 hydrogen bonds, but surprisingly did not contain a large content of 3(12) -helical structures, possibly due to the sparse distribution of the 3(12) -helical structure and other structures with acceptor+2 hydrogen bonds. On the other hand, despite its backbone flexibility, the β-alanine dodecamer had more stable and persistent <3.0 Å hydrogen bonds. Its structure was dominated more by multicentered hydrogen bonds than either oligoglycine or oligoalanine helices. The 3(1) (PII) helical structure, prevalent in oligoglycine and oligoalanine, does not appear to be stable in oligo-β-alanine indicating its competition with other structures (stacking structure as indicated by MD analyses). These differences are among the factors that shape helical structural preferences and the relative stabilities of these three oligopeptides.
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Affiliation(s)
- Chengyu Liu
- Department of Chemistry, Washington University, St. Louis, Missouri, 63130
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Abstract
We have studied stability of polyalanine alpha-helices with lysine residues added at C-and N-termini in gas-phase and aqueous solution. Monte Carlo simulations with the fixed-charges OPLS-AA and our polarizable POSSIM force fields were carried out. The results of the simulations confirm previously observed phenomena of the helix being stable with the LYS residue on the C-terminus and losing its helical structure if the charged LYS residue is located at the N-terminus of the polypeptide in gas-hase. Both OPLS-AA and POSSIM force fields performed essentially similarly, thus validity of the both for reproducing and predicting structures of such polypeptides has been confirmed. We have also studied the effect of replacing the normal N- and C-termini with methyl capping (this approach is often used in computational studies). Our results have demonstrated that the structure and stability of the polypeptides do not depend significantly on such a substitution although details of the resulting structure may change. The liquid-state simulations produced stable alpha-helixes regardless of the position of the protonated lysine residue. Overall, we have validated our polarizable POSSIM force field and the techniques used in the simulations, since the change of the helix structure as a function of the position of the LYS residue depends on a fine balance of energy contributions, and our methodology reproduced this balance well.
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Affiliation(s)
- Sergei Y Ponomarev
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, MA 01609
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