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Grelich-Mucha M, Bachelart T, Torbeev V, Ożga K, Berlicki Ł, Olesiak-Bańska J. Amyloid engineering - how terminal capping modifies morphology and secondary structure of supramolecular peptide aggregates. Biomater Sci 2024; 12:1590-1602. [PMID: 38323504 DOI: 10.1039/d3bm01641b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2024]
Abstract
The effects of peptide N- and C-termini on aggregation behavior have been scarcely studied. Herein, we examine (105-115) peptide fragments of transthyretin (TTR) containing various functional groups at both termini and study their impact on the morphology and the secondary structure. We synthesized TTR(105-115) peptides functionalized with α-amino (H-), N-acetyl-α-amino (Ac-) or N,N-dimethyl-α-amino (DiMe-) groups at the N-terminus, and with amide (-NH2) or carboxyl (-OH) functions at the C-terminus. We also investigated quasi-racemic mixtures by mixing the L-enantiomers with the D-enantiomer capped by H- and -NH2 groups. We observed that fibril formation is promoted by the sufficient number of hydrogen bonds at peptides' termini. Moreover, the final morphology of the aggregates can be controlled by the functional groups at the N-terminus. Remarkably, all quasi-racemic mixtures resulted in the robust formation of fibrils. Overall, this work illustrates how modifications of peptide termini may help to engineer supramolecular aggregates with a predicted morphology.
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Affiliation(s)
- Manuela Grelich-Mucha
- Institute of Advanced Materials, Wroclaw University of Science and Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland.
| | - Thomas Bachelart
- École Supérieure de Biotechnologie de Strasbourg (ESBS), CNRS UMR 7242 Biotechnology and Cellular Signalling, University of Strasbourg, 67400 Illkirch, France
| | - Vladimir Torbeev
- École Supérieure de Biotechnologie de Strasbourg (ESBS), CNRS UMR 7242 Biotechnology and Cellular Signalling, University of Strasbourg, 67400 Illkirch, France
| | - Katarzyna Ożga
- Department of Bioorganic Chemistry, Faculty of Chemistry, Wroclaw University of Science and Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland
| | - Łukasz Berlicki
- Department of Bioorganic Chemistry, Faculty of Chemistry, Wroclaw University of Science and Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland
| | - Joanna Olesiak-Bańska
- Institute of Advanced Materials, Wroclaw University of Science and Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland.
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2
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Emenike B, Donovan J, Raj M. Multicomponent Oxidative Nitrile Thiazolidination Reaction for Selective Modification of N-terminal Dimethylation Posttranslational Modification. J Am Chem Soc 2023; 145:16417-16428. [PMID: 37486086 PMCID: PMC10401698 DOI: 10.1021/jacs.3c02369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Indexed: 07/25/2023]
Abstract
Protein α-N-terminal dimethylation (Nme2) is an underexplored posttranslational modification (PTM) despite the increasing implications of α-N-terminal dimethylation in vital physiological and pathological processes across diverse species; thus, it is imperative to identify the sites of α-N-terminal dimethylation in the proteome. So far, only ∼300 α-N-terminal methylation sites have been discovered including mono-, di-, and tri-methylation, due to the lack of a pan-selective method for detecting α-N-terminal dimethylation. Herein, we introduce the three-component coupling reaction, oxidative nitrile thiazolidination (OxNiTha) for chemoselective modification of α-Nme2 to thiazolidine ring in the presence of selectfluor, sodium cyanide, and 1,2 aminothiols. One of the major challenges in developing a pan-specific method for the selective modification of α-Nme2 PTM is the competing reaction with dimethyl lysine (Kme2) PTM of a similar structure. We tackle this challenge by trapping nitrile-modified Nme2 with aminothiols, leading to the conversion of Nme2 to a five-membered thiazolidine ring. Surprisingly, the 1,2 aminothiol reaction with nitrile-modified Kme2 led to de-nitrilation along with the de-methylation to generate monomethyl lysine (Kme1). We demonstrated the application of OxNiTha reaction in pan-selective and robust modification of α-Nme2 in peptides and proteins to thiazolidine functionalized with varying fluorescent and affinity tags under physiological conditions. Further study with cell lysate enabled the enrichment of Nme2 PTM containing proteins.
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3
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Chang YH. Impact of Protein N α-Modifications on Cellular Functions and Human Health. Life (Basel) 2023; 13:1613. [PMID: 37511988 PMCID: PMC10381334 DOI: 10.3390/life13071613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 07/14/2023] [Accepted: 07/17/2023] [Indexed: 07/30/2023] Open
Abstract
Most human proteins are modified by enzymes that act on the α-amino group of a newly synthesized polypeptide. Methionine aminopeptidases can remove the initiator methionine and expose the second amino acid for further modification by enzymes responsible for myristoylation, acetylation, methylation, or other chemical reactions. Specific acetyltransferases can also modify the initiator methionine and sometimes the acetylated methionine can be removed, followed by further modifications. These modifications at the protein N-termini play critical roles in cellular protein localization, protein-protein interaction, protein-DNA interaction, and protein stability. Consequently, the dysregulation of these modifications could significantly change the development and progression status of certain human diseases. The focus of this review is to highlight recent progress in our understanding of the roles of these modifications in regulating protein functions and how these enzymes have been used as potential novel therapeutic targets for various human diseases.
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Affiliation(s)
- Yie-Hwa Chang
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University Medical School, Saint Louis, MO 63104, USA
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4
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Chen P, Huang R, Hazbun TR. Unlocking the Mysteries of Alpha-N-Terminal Methylation and its Diverse Regulatory Functions. J Biol Chem 2023:104843. [PMID: 37209820 PMCID: PMC10293735 DOI: 10.1016/j.jbc.2023.104843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 05/11/2023] [Accepted: 05/12/2023] [Indexed: 05/22/2023] Open
Abstract
Protein post-translation modifications (PTMs) are a critical regulatory mechanism of protein function. Protein α-N-terminal (Nα) methylation is a conserved PTM across prokaryotes and eukaryotes. Studies of the Nα methyltransferases responsible for Να methylation and their substrate proteins have shown that the PTM involves diverse biological processes, including protein synthesis and degradation, cell division, DNA damage response, and transcription regulation. This review provides an overview of the progress toward the regulatory function of Να methyltransferases and their substrate landscape. More than 200 proteins in humans and 45 in yeast are potential substrates for protein Nα methylation based on the canonical recognition motif, XP[KR]. Based on recent evidence for a less stringent motif requirement, the number of substrates might be increased, but further validation is needed to solidify this concept. A comparison of the motif in substrate orthologs in selected eukaryotic species indicates intriguing gain and loss of the motif across the evolutionary landscape. We discuss the state of knowledge in the field that has provided insights into the regulation of protein Να methyltransferases and their role in cellular physiology and disease. We also outline the current research tools that are key to understanding Να methylation. Finally, challenges are identified and discussed that would aid in unlocking a system-level view of the roles of Να methylation in diverse cellular pathways.
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Affiliation(s)
- Panyue Chen
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana 47907, United States
| | - Rong Huang
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana 47907, United States; Purdue University Center for Cancer Research, Purdue University, West Lafayette, Indiana 47907, United States
| | - Tony R Hazbun
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana 47907, United States; Purdue University Center for Cancer Research, Purdue University, West Lafayette, Indiana 47907, United States.
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5
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Meng Y, Huang R. Site-specific methylation on α-N-terminus of peptides through chemical and enzymatic methods. Methods Enzymol 2023; 684:113-133. [PMID: 37230586 PMCID: PMC10525076 DOI: 10.1016/bs.mie.2023.02.008] [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] [Indexed: 05/27/2023]
Abstract
Protein α-N-terminal (Nα) methylation is a post-translational modification catalyzed by N-terminal methyltransferase 1/2 (NTMT1/2) and METTL13. Nα methylation affects protein stability, protein-protein interaction, and protein-DNA interaction. Thus, Nα methylated peptides are essential tools to study the function of Nα methylation, generate specific antibodies for different states of Nα methylation, and characterize the enzyme kinetics and activity. Here, we describe chemical methods of site-specific synthesis of Nα mono-, di-, and trimethylated peptides in the solid phase. In addition, we describethe preparation of trimethylation peptides by recombinant NTMT1 catalysis.
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Affiliation(s)
- Ying Meng
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue Institute for Drug Discovery, Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN, United States
| | - Rong Huang
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue Institute for Drug Discovery, Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN, United States.
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6
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Conner MM, Schaner Tooley CE. Three's a crowd - why did three N-terminal methyltransferases evolve for one job? J Cell Sci 2023; 136:jcs260424. [PMID: 36647772 PMCID: PMC10022744 DOI: 10.1242/jcs.260424] [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] [Indexed: 01/18/2023] Open
Abstract
N-terminal methylation of the α-amine group (Nα-methylation) is a post-translational modification (PTM) that was discovered over 40 years ago. Although it is not the most abundant of the Nα-PTMs, there are more than 300 predicted substrates of the three known mammalian Nα-methyltransferases, METTL11A and METTL11B (also known as NTMT1 and NTMT2, respectively) and METTL13. Of these ∼300 targets, the bulk are acted upon by METTL11A. Only one substrate is known to be Nα-methylated by METTL13, and METTL11B has no proven in vivo targets or predicted targets that are not also methylated by METTL11A. Given that METTL11A could clearly handle the entire substrate burden of Nα-methylation, it is unclear why three distinct Nα-methyltransferases have evolved. However, recent evidence suggests that many methyltransferases perform important biological functions outside of their catalytic activity, and the Nα-methyltransferases might be part of this emerging group. Here, we describe the distinct expression, localization and physiological roles of each Nα-methyltransferase, and compare these characteristics to other methyltransferases with non-catalytic functions, as well as to methyltransferases with both catalytic and non-catalytic functions, to give a better understanding of the global roles of these proteins. Based on these comparisons, we hypothesize that these three enzymes do not just have one common function but are actually performing three unique jobs in the cell.
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Affiliation(s)
- Meghan M. Conner
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY 14203, USA
| | - Christine E. Schaner Tooley
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY 14203, USA
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7
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Zhou Q, Wu W, Jia K, Qi G, Sun XS, Li P. Design and characterization of PROTAC degraders specific to protein N-terminal methyltransferase 1. Eur J Med Chem 2022; 244:114830. [PMID: 36228414 PMCID: PMC10520980 DOI: 10.1016/j.ejmech.2022.114830] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2022] [Revised: 09/26/2022] [Accepted: 10/01/2022] [Indexed: 11/24/2022]
Abstract
Protein N-terminal methylation catalyzed by N-terminal methyltransferase 1 (NTMT1) is an emerging methylation present in eukaryotes, playing important regulatory roles in various biological and cellular processes. Although dysregulation of NTMT1 has been linked to many diseases such as colorectal cancer, their molecular and cellular mechanisms remain elusive due to inaccessibility to an effective cellular probe. Here we report the design, synthesis, and characterization of the first-in-class NTMT1 degraders based on proteolysis-targeting chimera (PROTAC) strategy. Through a brief structure-activity relationship (SAR) study of linker length, a cell permeable degrader 1 involving a von Hippel-Lindau (VHL) E3 ligase ligand was developed and demonstrated to reduce NTMT1 protein levels effectively and selectively in time- and dose-dependent manners in colorectal carcinoma cell lines HCT116 and HT29. Degrader 1 displayed DC50 = 7.53 μM and Dmax > 90% in HCT116 (cellular IC50 > 100 μM for its parent inhibitor DC541). While degrader 1 had marginal cytotoxicity, it displayed anti-proliferative activity in 2D and 3D culture environment, resulting from cell cycle arrested at G0/G1 phase in HCT116. Label-free global proteomic analysis revealed that degrader 1 induced overexpression of calreticulin (CALR), an immunogenic cell death (ICD) signal protein that is known to elicit antitumor immune response and clinically linked to a high survival rate of patients with colorectal cancer upon its upregulation. Collectively, degrader 1 offers the first selective cellular probe for NTMT1 exploration and a new drug discovery modality for NTMT1-related oncology and diseases.
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Affiliation(s)
- Qilong Zhou
- Department of Chemistry, Kansas State University, Manhattan, KS, 66506, USA; Laboratory of Ethnopharmacology, Tissue-orientated Property of Chinese Medicine Key Laboratory of Sichuan Province, West China School of Medicine
| | - Wei Wu
- Department of Chemistry, Kansas State University, Manhattan, KS, 66506, USA
| | - Kaimin Jia
- Department of Chemistry, Kansas State University, Manhattan, KS, 66506, USA
| | - Guangyan Qi
- Department of Grain Science and Industry, Kansas State University, Manhattan, KS, 66506, USA
| | - Xiuzhi Susan Sun
- Department of Grain Science and Industry, Kansas State University, Manhattan, KS, 66506, USA; Department of Biological and Agricultural Engineering, Kansas State University, Manhattan, KS, 66506, USA
| | - Ping Li
- Department of Chemistry, Kansas State University, Manhattan, KS, 66506, USA.
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8
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Microbial cytosine deaminase is a programmable anticancer prodrug mediating enzyme: antibody, and gene directed enzyme prodrug therapy. Heliyon 2022; 8:e10660. [PMID: 36164544 PMCID: PMC9508425 DOI: 10.1016/j.heliyon.2022.e10660] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 03/26/2022] [Accepted: 09/09/2022] [Indexed: 11/24/2022] Open
Abstract
Cytosine deaminase (CDA) is a non-mammalian enzyme with powerful activity in mediating the prodrug 5-fluorcytosine (5-FC) into toxic drug 5-fluorouracil (5-FU), as an alternative directed approach for the traditional chemotherapies and radiotherapies of cancer. This enzyme has been frequently reported and characterized from various microorganisms. The therapeutic strategy of 5-FC-CDA involves the administration of CDA followed by the prodrug 5-FC injection to generate cytotoxic 5-FU. The antiproliferative activity of CDA-5-FC elaborates from the higher activity of uracil pathway in tumor cells than normal ones. The main challenge of the therapeutic drug 5-FU are the short half-life, lack of selectivity and emergence of the drug resistance, consistently to the other chemotherapies. So, mediating the 5-FU to the tumor cells by CDA is one of the most feasible approaches to direct the drug to the tumor cells, reducing its toxic effects and improving their pharmacokinetic properties. Nevertheless, the catalytic efficiency, stability, antigenicity and targetability of CDA-5-FC, are the major challenges that limit the clinical application of this approach. Thus, exploring the biochemical properties of CDA from various microorganisms, as well as the approaches for localizing the system of CDA-5-FC to the tumor cells via the antibody directed enzyme prodrug therapy (ADEPT) and gene directed prodrug therapy (GDEPT) were the objectives of this review. Finally, the perspectives for increasing the therapeutic efficacy, and targetability of the CDA-5-FC system were described.
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9
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Abdelraheem E, Thair B, Varela RF, Jockmann E, Popadić D, Hailes HC, Ward JM, Iribarren AM, Lewkowicz ES, Andexer JN, Hagedoorn PL, Hanefeld U. Methyltransferases, functions and applications. Chembiochem 2022; 23:e202200212. [PMID: 35691829 PMCID: PMC9539859 DOI: 10.1002/cbic.202200212] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 06/10/2022] [Indexed: 11/25/2022]
Abstract
In this review the current state‐of‐the‐art of S‐adenosylmethionine (SAM)‐dependent methyltransferases and SAM are evaluated. Their structural classification and diversity is introduced and key mechanistic aspects presented which are then detailed further. Then, catalytic SAM as a target for drugs, and approaches to utilise SAM as a cofactor in synthesis are introduced with different supply and regeneration approaches evaluated. The use of SAM analogues are also described. Finally O‐, N‐, C‐ and S‐MTs, their synthetic applications and potential for compound diversification is given.
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Affiliation(s)
| | - Benjamin Thair
- University College London Faculty of Mathematical and Physical Sciences, department of Chemistry, UNITED KINGDOM
| | - Romina Fernández Varela
- Universidad nacional di Quilmes, 3Laboratorio de Biotransformaciones y Química de Ácidos Nucleicos, ARGENTINA
| | - Emely Jockmann
- Albert-Ludwigs-Universitat Freiburg Universitatsbibliothek Freiburg, Pharmacie, GERMANY
| | | | - Helen C Hailes
- University College London Faculty of Mathematical and Physical Sciences, department of Chemistry, UNITED KINGDOM
| | - John M Ward
- University College London, Department of Biochemical Engineering, UNITED KINGDOM
| | - Adolfo M Iribarren
- Universidad Nacional de Quilmes, 3Laboratorio de Biotransformaciones y Química de Ácidos Nucleicos, ARGENTINA
| | - Elizabeth S Lewkowicz
- Universidad Nacional de Quilmes, Laboratorio de Biotransformaciones y Química de Ácidos Nucleicos, ARGENTINA
| | | | | | - Ulf Hanefeld
- Technische Universiteit Delft, Gebouw voor Scheikunde, Julianalaan 136, 2628 BL, Delft, NETHERLANDS
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10
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Conner MM, Parker HV, Falcone DR, Chung G, Schaner Tooley CE. Novel regulation of the transcription factor ZHX2 by N-terminal methylation. Transcription 2022; 13:1-15. [PMID: 35613330 DOI: 10.1080/21541264.2022.2079184] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
N-terminal methylation (Nα-methylation) by the methyltransferase NRMT1 is an important post-translational modification that regulates protein-DNA interactions. Accordingly, its loss impairs functions that are reliant on such interactions, including DNA repair and transcriptional regulation. The global loss of Nα-methylation results in severe developmental and premature aging phenotypes, but given over 300 predicted substrates, it is hard to discern which physiological substrates contribute to each phenotype. One of the most striking phenotypes in NRMT1 knockout (Nrmt1-/-) mice is early liver degeneration. To identify the disrupted signaling pathways leading to this phenotype and the NRMT1 substrates involved, we performed RNA-sequencing analysis of control and Nrmt1-/- adult mouse livers. We found both a significant upregulation of transcripts in the cytochrome P450 (CYP) family and downregulation of transcripts in the major urinary protein (MUP) family. Interestingly, transcription of both families is inversely regulated by the transcription factor zinc fingers and homeoboxes 2 (ZHX2). ZHX2 contains a non-canonical NRMT1 consensus sequence, indicating that its function could be directly regulated by Nα-methylation. We confirmed misregulation of CYP and MUP mRNA and protein levels in Nrmt1-/- livers and verified NRMT1 can methylate ZHX2 in vitro. In addition, we used a mutant of ZHX2 that cannot be methylated to directly demonstrate Nα-methylation promotes ZHX2 transcription factor activity and target promoter occupancy. Finally, we show Nrmt1-/- mice also exhibit early postnatal de-repression of ZHX2 targets involved in fetal liver development. Taken together, these data implicate ZHX2 misregulation as a driving force behind the liver phenotype seen in Nrmt1-/- mice.
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Affiliation(s)
- Meghan M Conner
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Haley V Parker
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Daniela R Falcone
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Gehoon Chung
- Department of Oral Physiology and Program in Neurobiology, School of Dentistry, Seoul National University, Seoul, South Korea
| | - Christine E Schaner Tooley
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
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11
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Chen P, Paschoal Sobreira TJ, Hall MC, Hazbun TR. Discovering the N-Terminal Methylome by Repurposing of Proteomic Datasets. J Proteome Res 2021; 20:4231-4247. [PMID: 34382793 DOI: 10.1021/acs.jproteome.1c00009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Protein α-N-methylation is an underexplored post-translational modification involving the covalent addition of methyl groups to the free α-amino group at protein N-termini. To systematically explore the extent of α-N-terminal methylation in yeast and humans, we reanalyzed publicly accessible proteomic datasets to identify N-terminal peptides contributing to the α-N-terminal methylome. This repurposing approach found evidence of α-N-methylation of established and novel protein substrates with canonical N-terminal motifs of established α-N-terminal methyltransferases, including human NTMT1/2 and yeast Tae1. NTMT1/2 are implicated in cancer and aging processes but have unclear and context-dependent roles. Moreover, α-N-methylation of noncanonical sequences was surprisingly prevalent, suggesting unappreciated and cryptic methylation events. Analysis of the amino acid frequencies of α-N-methylated peptides revealed a [S]1-[S/A/Q]2 pattern in yeast and [A/N/G]1-[A/S/V]2-[A/G]3 in humans, which differs from the canonical motif. We delineated the distribution of the two types of prevalent N-terminal modifications, acetylation and methylation, on amino acids at the first position. We tested three potentially methylated proteins and confirmed the α-N-terminal methylation of Hsp31 by additional proteomic analysis and immunoblotting. The other two proteins, Vma1 and Ssa3, were found to be predominantly acetylated, indicating that proteomic searching for α-N-terminal methylation requires careful consideration of mass spectra. This study demonstrates the feasibility of reprocessing proteomic data for global α-N-terminal methylome investigations.
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Affiliation(s)
- Panyue Chen
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana 47907, United States
| | | | - Mark C Hall
- Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907, United States.,Purdue Center for Cancer Research, Purdue University, West Lafayette, Indiana 47907, United States
| | - Tony R Hazbun
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana 47907, United States.,Purdue Center for Cancer Research, Purdue University, West Lafayette, Indiana 47907, United States
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12
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Chen L, Kashina A. Post-translational Modifications of the Protein Termini. Front Cell Dev Biol 2021; 9:719590. [PMID: 34395449 PMCID: PMC8358657 DOI: 10.3389/fcell.2021.719590] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 06/30/2021] [Indexed: 12/12/2022] Open
Abstract
Post-translational modifications (PTM) involve enzyme-mediated covalent addition of functional groups to proteins during or after synthesis. These modifications greatly increase biological complexity and are responsible for orders of magnitude change between the variety of proteins encoded in the genome and the variety of their biological functions. Many of these modifications occur at the protein termini, which contain reactive amino- and carboxy-groups of the polypeptide chain and often are pre-primed through the actions of cellular machinery to expose highly reactive residues. Such modifications have been known for decades, but only a few of them have been functionally characterized. The vast majority of eukaryotic proteins are N- and C-terminally modified by acetylation, arginylation, tyrosination, lipidation, and many others. Post-translational modifications of the protein termini have been linked to different normal and disease-related processes and constitute a rapidly emerging area of biological regulation. Here we highlight recent progress in our understanding of post-translational modifications of the protein termini and outline the role that these modifications play in vivo.
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Affiliation(s)
| | - Anna Kashina
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, United States
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13
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Past, present, and perspectives of protein N-terminal methylation. Curr Opin Chem Biol 2021; 63:115-122. [PMID: 33839647 DOI: 10.1016/j.cbpa.2021.02.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 02/21/2021] [Accepted: 02/25/2021] [Indexed: 01/16/2023]
Abstract
The posttranslational methylation of the α-N-terminal amino group of proteins was first documented over 40 years ago, but the functional significance of this modification has been underexplored relative to lysine and arginine methylation. Increasing reports implicates α-N-terminal methylation as a widespread and critical regulator of mitosis, chromatin interactions, DNA repair, and translation fidelity. Here, we summarize advances in the current understanding of protein α-N-terminal methylation biological functions and mechanisms across eukaryotic organisms. Also, we describe the recent literature on substrate recognition and the discovery of potent and selective inhibitors for protein N-terminal methyltransferases. Finally, we summarize the emergent crosstalk between α-N-terminal methylation and other N-terminal modifications.
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14
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Park IG, Jeon M, Kim H, Lee JM. Coordinated methyl readers: Functional communications in cancer. Semin Cancer Biol 2021; 83:88-99. [PMID: 33753223 DOI: 10.1016/j.semcancer.2021.03.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 02/18/2021] [Accepted: 03/16/2021] [Indexed: 01/28/2023]
Abstract
Methylation is a major post-translational modification (PTM) generated by methyltransferase on target proteins; it is recognized by the epigenetic reader to expand the functional diversity of proteins. Methylation can occur on specific lysine or arginine residues localized within regulatory domains in both histone and nonhistone proteins, thereby allowing distinguished properties of the targeted protein. Methylated residues are recognized by chromodomain, malignant brain tumor (MBT), Tudor, plant homeodomain (PHD), PWWP, WD-40, ADD, and ankyrin repeats by an induced-fit mechanism. Methylation-dependent activities regulate distinct aspects of target protein function and are largely reliant on methyl readers of histone and nonhistone proteins in various diseases. Methylation of nonhistone proteins that are recognized by methyl readers facilitates the degradation of unwanted proteins, as well as the stabilization of necessary proteins. Unlike nonhistone substrates, which are mainly monomethylated by methyltransferase, histones are di- or trimethylated by the same methyltransferases and then connected to other critical regulators by methyl readers. These fine-tuned controls by methyl readers are significant for the progression or inhibition of diseases, including cancers. Here, current knowledge and our perspectives about regulating protein function by methyl readers are summarized. We also propose that expanded research on the strong crosstalk mechanisms between methylation and other PTMs via methyl readers would augment therapeutic research in cancer.
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Affiliation(s)
- Il-Geun Park
- Department of Molecular Bioscience, College of Biomedical Sciences, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Minsol Jeon
- Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul 02841, Republic of Korea; BK21 Graduate Program, Department of Biomedical Sciences, Korea University College of Medicine, Seoul 02841, Republic of Korea
| | - Hyunkyung Kim
- Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul 02841, Republic of Korea; BK21 Graduate Program, Department of Biomedical Sciences, Korea University College of Medicine, Seoul 02841, Republic of Korea.
| | - Ji Min Lee
- Department of Molecular Bioscience, College of Biomedical Sciences, Kangwon National University, Chuncheon 24341, Republic of Korea.
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15
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Modulation of N-terminal methyltransferase 1 by an N 6-methyladenosine-based epitranscriptomic mechanism. Biochem Biophys Res Commun 2021; 546:54-58. [PMID: 33561748 DOI: 10.1016/j.bbrc.2021.01.088] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Accepted: 01/26/2021] [Indexed: 11/22/2022]
Abstract
Protein α-N-methylation is an evolutionarily conserved type of post-translational modification; however, little is known about the regulatory mechanisms for this modification. Methylation at the N6 position of adenosine in mRNAs is dynamic and modulates their stability, splicing, and translational efficiency. Here, we found that the expression of N-terminal methyltransferase 1 (NTMT1) protein is altered by depletion of those genes encoding the reader/writer/eraser proteins of N6-methyladenosine (m6A). We also observed that MRG15 is N-terminally methylated by NTMT1, and this methylation could also be modulated by reader/writer/eraser proteins of m6A. Together, these results revealed a novel m6A-based epitranscriptomic mechanism in regulating protein N-terminal methylation.
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16
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Zacarias E, Casas-Mollano JA. Cataloging Posttranslational Modifications in Plant Histones. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1346:131-154. [DOI: 10.1007/978-3-030-80352-0_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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17
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Zhou M, Malhan N, Ahkami AH, Engbrecht K, Myers G, Dahlberg J, Hollingsworth J, Sievert JA, Hutmacher R, Madera M, Lemaux PG, Hixson KK, Jansson C, Paša-Tolić L. Top-down mass spectrometry of histone modifications in sorghum reveals potential epigenetic markers for drought acclimation. Methods 2020; 184:29-39. [DOI: 10.1016/j.ymeth.2019.10.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 10/10/2019] [Accepted: 10/21/2019] [Indexed: 12/30/2022] Open
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18
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Porębska A, Różycka M, Hołubowicz R, Szewczuk Z, Ożyhar A, Dobryszycki P. Functional derivatives of human dentin matrix protein 1 modulate morphology of calcium carbonate crystals. FASEB J 2020; 34:6147-6165. [PMID: 32190922 DOI: 10.1096/fj.201901999r] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 02/07/2020] [Accepted: 02/21/2020] [Indexed: 12/23/2022]
Abstract
Dentin matrix protein 1 (DMP1) is an acidic, extracellular matrix protein essential for biomineralization of calcium phosphate, in bone and dentin. It is proteolytically processed into two fragments, 44K and 56K. Recently, the presence of DMP1 was noticed in inner ear, specifically in otoconia, which are calcium carbonate biominerals involved in sensing of balance. In this study, the solution structure and biomineralization activity of otoconial 44K and 56K fragments toward calcium carbonate were investigated. The results of analytical ultracentrifugation, circular dichroism, and gel filtration indicated that DMP1 fragments are disordered in solution. Notably, 56K formed oligomers in the presence of calcium ions. It was also observed that both fragments influenced the crystal growth by in vitro biomineralization assay and scanning electron microscopy. In addition, they sequester the calcium ions during the calcite formation. Calcium carbonate crystals precipitated in vitro changed their size and shape in the presence of DMP1 fragments. Oligomerization propensity of 56K may significantly enhance this function. Our study indicates that intrinsically disordered DMP1 has a previously unknown regulatory function for biomineralization of otoconia.
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Affiliation(s)
- Aleksandra Porębska
- Department of Biochemistry, Molecular Biology and Biotechnology, Faculty of Chemistry, Wrocław University of Science and Technology, Wrocław, Poland
| | - Mirosława Różycka
- Department of Biochemistry, Molecular Biology and Biotechnology, Faculty of Chemistry, Wrocław University of Science and Technology, Wrocław, Poland
| | - Rafał Hołubowicz
- Department of Biochemistry, Molecular Biology and Biotechnology, Faculty of Chemistry, Wrocław University of Science and Technology, Wrocław, Poland
| | | | - Andrzej Ożyhar
- Department of Biochemistry, Molecular Biology and Biotechnology, Faculty of Chemistry, Wrocław University of Science and Technology, Wrocław, Poland
| | - Piotr Dobryszycki
- Department of Biochemistry, Molecular Biology and Biotechnology, Faculty of Chemistry, Wrocław University of Science and Technology, Wrocław, Poland
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19
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Hocine S, Berger G, Hanessian S. Design and Synthesis of Backbone-Fused, Conformationally Constrained Morpholine-Proline Chimeras. J Org Chem 2020; 85:4237-4247. [PMID: 32134267 DOI: 10.1021/acs.joc.9b03413] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
We report the synthesis of two novel bridged morpholine-proline chimeras 4 and 5, which represent rigid conformationally locked three-dimensional structures wherein the lone pairs of electrons on oxygen and nitrogen are oriented in spatially different "east-west" and "north-west" directions, respectively. In combination with the presence of a carboxylic acid, the electronic features of these compounds may be useful in the context of peptidomimetic design of biologically relevant compounds. Quantitative estimates of the basicity of the nitrogen atoms were obtained using conceptual density functional theory analysis.
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Affiliation(s)
- Sofiane Hocine
- Department of Chemistry, Université de Montréal, Station Centre-Ville, C.P. 6128, Montreal, Quebec H3C 3J7, Canada
| | - Gilles Berger
- Microbiology, Bioorganic & Macromolecular Chemistry, Faculty of Pharmacy, Université Libre de Bruxelles, Boulevard du Triomphe, Brussels 1050, Belgium
| | - Stephen Hanessian
- Department of Chemistry, Université de Montréal, Station Centre-Ville, C.P. 6128, Montreal, Quebec H3C 3J7, Canada
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20
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Jin Y, Diffee GM, Colman RJ, Anderson RM, Ge Y. Top-down Mass Spectrometry of Sarcomeric Protein Post-translational Modifications from Non-human Primate Skeletal Muscle. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:2460-2469. [PMID: 30834509 PMCID: PMC6722035 DOI: 10.1007/s13361-019-02139-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 01/11/2019] [Accepted: 01/12/2019] [Indexed: 05/22/2023]
Abstract
Sarcomeric proteins, including myofilament and Z-disk proteins, play critical roles in regulating muscle contractile properties. A variety of isoforms and post-translational modifications (PTMs) of sarcomeric proteins have been shown to be associated with modulation of muscle functions and the occurrence of muscle diseases. Non-human primates (NHPs) are excellent research models for sarcopenia, a disease associated with alterations in sarcomeric proteins, due to their marked similarities to humans. However, the sarcomeric proteins in NHP skeletal muscle have not been well characterized. To gain a deeper understanding of sarcomeric proteins in NHP skeletal muscle, we employed top-down mass spectrometry (MS) to conduct a comprehensive analysis on isoforms and PTMs of sarcomeric proteins in rhesus macaque skeletal muscle. We identified 23 protein isoforms with 46 proteoforms of sarcomeric proteins, including 6 isoforms with 18 proteoforms from fast skeletal troponin T. Particularly, for the first time, a novel PDZ/LIM domain protein isoform, PDLIM7, was characterized with a newly identified protein sequence. Moreover, we also identified multiple PTMs on these proteins, including deamidation, methylation, acetylation, tri-methylation, phosphorylation, and S-glutathionylation. Most PTM sites were localized, including Asn13 deamidation on MLC-2S; His73 methylation on αactin; N-terminal acetylation on most identified proteins; N-terminal tri-methylation on MLC-1S, MLC-1F, MLC-2S, and MLC-2F; Ser14 phosphorylation on MLC-2S; and Ser15 and Ser16 phosphorylation on MLC-2F. In summary, a comprehensive characterization of sarcomeric proteins including multiple isoforms and PTMs in NHP skeletal muscle was achieved by analyzing intact proteins in the top-down MS approach.
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Affiliation(s)
- Yutong Jin
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Gary M Diffee
- Department of Kinesiology, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Ricki J Colman
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, WI, 53715, USA
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Rozalyn M Anderson
- Department of Medicine, University of Wisconsin-Madison, Madison, WI, 53705, USA
- Geriatric Research Education and Clinical Center, William S. Middleton Memorial Veterans Hospital, Madison, WI, 53705, USA
| | - Ying Ge
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA.
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI, 53705, USA.
- Human Proteomics Program, University of Wisconsin-Madison, Madison, WI, 53705, USA.
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21
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Levy D. Lysine methylation signaling of non-histone proteins in the nucleus. Cell Mol Life Sci 2019; 76:2873-2883. [PMID: 31123776 PMCID: PMC11105312 DOI: 10.1007/s00018-019-03142-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 05/10/2019] [Indexed: 12/18/2022]
Abstract
Lysine methylation, catalyzed by protein lysine methyltransferases (PKMTs), is a central post-translational modification regulating many signaling pathways. It has direct and indirect effects on chromatin structure and transcription. Accumulating evidence suggests that dysregulation of PKMT activity has a fundamental impact on the development of many pathologies. While most of these works involve in-depth analysis of methylation events in the context of histones, in recent years, it has become evident that methylation of non-histone proteins also plays a pivotal role in cell processes. This review highlights the importance of non-histone methylation, with focus on methylation events taking place in the nucleus. Known experimental platforms which were developed to identify new methylation events, as well as examples of specific lysine methylation signaling events which regulate key transcription factors, are presented. In addition, the role of these methylation events in normal and disease states is emphasized.
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Affiliation(s)
- Dan Levy
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Ben-Gurion University of the Negev, 84105, Beersheba, Israel.
- The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, P.O.B. 653, 84105, Beersheba, Israel.
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22
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Abstract
Protein α‐N‐terminal methylation is catalyzed by protein N‐terminal methyltransferases. The prevalent occurrence of this methylation in ribosomes, myosin, and histones implies its function in protein–protein interactions. Although its full spectrum of function has not yet been outlined, recent discoveries have revealed the emerging roles of α‐N‐terminal methylation in protein–chromatin interactions, DNA damage repair, and chromosome segregation. Herein, an overview of the discovery of protein N‐terminal methyltransferases and functions of α‐N‐terminal methylation is presented. In addition, substrate recognition, mechanisms, and inhibition of N‐terminal methyltransferases are reviewed. Opportunities and gaps in protein α‐N‐terminal methylation are also discussed.
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Affiliation(s)
- Rong Huang
- Department of Medicinal Chemistry and Molecular PharmacologyCenter for Cancer Research, Institute for Drug DiscoveryPurdue University West Lafayette IN 47907 USA
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23
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Hyslop JF, Lovelock SL, Watson AJB, Sutton PW, Roiban GD. N-Alkyl-α-amino acids in Nature and their biocatalytic preparation. J Biotechnol 2019; 293:56-65. [PMID: 30690098 DOI: 10.1016/j.jbiotec.2019.01.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 12/18/2018] [Accepted: 01/03/2019] [Indexed: 11/16/2022]
Abstract
N-Alkylated-α-amino acids are useful building blocks for the pharmaceutical and fine chemical industries. Enantioselective methods of N-alkylated-α-amino acid synthesis are therefore highly valuable and widely investigated. While there are a variety of chemical methods for their synthesis, they often employ stoichiometric quantities of hazardous reagents such as pyrophoric metal hydrides or genotoxic alkylating agents, whereas biocatalytic routes can provide a greener and cleaner alternative to existing methods. This review highlights the occurrence of the N-alkyl-α-amino acid motif and its role in nature, important applications towards human health and biocatalytic methods of preparation. Several enzyme classes that can be used to access chiral N-alkylated-α-amino acids and their substrate selectivities are detailed.
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Affiliation(s)
- Julia F Hyslop
- Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow, G1 1XL, UK; Advanced Manufacturing Technologies, GlaxoSmithKline, Medicines Research Centre, Gunnels Wood Road, Stevenage, SG1 2NY, UK
| | - Sarah L Lovelock
- Manchester Institute of Biotechnology, School of Chemistry, University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK
| | - Allan J B Watson
- EaStCHEM, School of Chemistry, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST, UK
| | - Peter W Sutton
- Department of Chemical, Biological and Environmental Engineering, Group of Bioprocess Engineering and Applied Biocatalysis, Universitat Autònoma de Barcelona, 08193, Bellaterra, (Cerdanyola del Vallès), Catalunya, Spain.
| | - Gheorghe-Doru Roiban
- Advanced Manufacturing Technologies, GlaxoSmithKline, Medicines Research Centre, Gunnels Wood Road, Stevenage, SG1 2NY, UK.
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24
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Mindt M, Walter T, Risse JM, Wendisch VF. Fermentative Production of N-Methylglutamate From Glycerol by Recombinant Pseudomonas putida. Front Bioeng Biotechnol 2018; 6:159. [PMID: 30474025 PMCID: PMC6237917 DOI: 10.3389/fbioe.2018.00159] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 10/16/2018] [Indexed: 12/02/2022] Open
Abstract
N-methylated amino acids are present in diverse biological molecules in bacteria, archaea and eukaryotes. There is an increasing interest in this molecular class of alkylated amino acids by the pharmaceutical and chemical industries. N-alkylated amino acids have desired functions such as higher proteolytic stability, enhanced membrane permeability and longer peptide half-lives, which are important for the peptide-based drugs, the so-called peptidomimetics. Chemical synthesis of N-methylated amino acids often is limited by incomplete stereoselectivity, over-alkylation or the use of hazardous chemicals. Here, we describe metabolic engineering of Pseudomonas putida KT2440 for the fermentative production of N-methylglutamate from simple carbon sources and monomethylamine. P. putida KT2440, which is generally recognized as safe and grows with glucose and the alternative feedstock glycerol as sole carbon and energy source, was engineered for the production of N-methylglutamate using heterologous enzymes from Methylobacterium extorquens. About 3.9 g L−1N-methylglutamate accumulated within 48 h in shake flask cultures with minimal medium containing monomethylamine and glycerol. A fed-batch cultivation process yielded a N-methylglutamate titer of 17.9 g L−1.
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Affiliation(s)
- Melanie Mindt
- Genetics of Prokaryotes, Faculty of Biology and CeBiTec, Bielefeld University, Bielefeld, Germany
| | - Tatjana Walter
- Genetics of Prokaryotes, Faculty of Biology and CeBiTec, Bielefeld University, Bielefeld, Germany
| | - Joe Max Risse
- Fermentation Technology, Technical Faculty and CeBiTec, Bielefeld University, Bielefeld, Germany
| | - Volker F Wendisch
- Genetics of Prokaryotes, Faculty of Biology and CeBiTec, Bielefeld University, Bielefeld, Germany
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25
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Dong C, Dong G, Li L, Zhu L, Tempel W, Liu Y, Huang R, Min J. An asparagine/glycine switch governs product specificity of human N-terminal methyltransferase NTMT2. Commun Biol 2018; 1:183. [PMID: 30417120 PMCID: PMC6214909 DOI: 10.1038/s42003-018-0196-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 10/15/2018] [Indexed: 01/11/2023] Open
Abstract
α-N-terminal methylation of proteins is an important post-translational modification that is catalyzed by two different N-terminal methyltransferases, namely NTMT1 and NTMT2. Previous studies have suggested that NTMT1 is a tri-methyltransferase, whereas NTMT2 is a mono-methyltransferase. Here, we report the first crystal structures, to our knowledge, of NTMT2 in binary complex with S-adenosyl-L-methionine as well as in ternary complex with S-adenosyl-L-homocysteine and a substrate peptide. Our structural observations combined with biochemical studies reveal that NTMT2 is also able to di-/tri-methylate the GPKRIA peptide and di-methylate the PPKRIA peptide, otherwise it is predominantly a mono-methyltransferase. The residue N89 of NTMT2 serves as a gatekeeper residue that regulates the binding of unmethylated versus monomethylated substrate peptide. Structural comparison of NTMT1 and NTMT2 prompts us to design a N89G mutant of NTMT2 that can profoundly alter its catalytic activities and product specificities. Cheng Dong et al. resolve the crystal structure of NTMT2, presenting the molecular basis for substrate recognition. Using structural and biochemical studies, they identified a specific residue within NTMT2 that controls its binding affinity to unmethylated or monomethylated substrates.
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Affiliation(s)
- Cheng Dong
- Structural Genomics Consortium, University of Toronto, Toronto, M5G1L7, ON, Canada
| | - Guangping Dong
- Department of Medicinal Chemistry and Molecular Pharmacology, Center for Cancer Research, Institute for Drug Discovery, Purdue University, West Lafayette, IN, 47907, USA
| | - Li Li
- Structural Genomics Consortium, University of Toronto, Toronto, M5G1L7, ON, Canada
| | - Licheng Zhu
- Structural Genomics Consortium, University of Toronto, Toronto, M5G1L7, ON, Canada.,School of Life Sciences, Jinggangshan University, 343009, Ji'an, Jiangxi, China
| | - Wolfram Tempel
- Structural Genomics Consortium, University of Toronto, Toronto, M5G1L7, ON, Canada
| | - Yanli Liu
- Structural Genomics Consortium, University of Toronto, Toronto, M5G1L7, ON, Canada
| | - Rong Huang
- Department of Medicinal Chemistry and Molecular Pharmacology, Center for Cancer Research, Institute for Drug Discovery, Purdue University, West Lafayette, IN, 47907, USA.
| | - Jinrong Min
- Structural Genomics Consortium, University of Toronto, Toronto, M5G1L7, ON, Canada. .,Department of Physiology, University of Toronto, Toronto, M5S 1A8, ON, Canada.
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26
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N-terminal acetylation and methylation differentially affect the function of MYL9. Biochem J 2018; 475:3201-3219. [PMID: 30242065 DOI: 10.1042/bcj20180638] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 09/18/2018] [Accepted: 09/19/2018] [Indexed: 12/30/2022]
Abstract
Deciphering the histone code has illustrated that acetylation or methylation on the same residue can have analogous or opposing roles. However, little is known about the interplay between these post-translational modifications (PTMs) on the same nonhistone residues. We have recently discovered that N-terminal acetyltransferases (NATs) and N-terminal methyltransferases (NRMTs) can have overlapping substrates and identified myosin regulatory light chain 9 (MYL9) as the first confirmed protein to occur in either α-amino-methylated (Nα-methyl) or α-amino-acetylated (Nα-acetyl) states in vivo Here we aim to determine if these PTMs function similarly or create different MYL9 proteoforms with distinct roles. We use enzymatic assays to directly verify MYL9 is a substrate of both NRMT1 and NatA and generate mutants of MYL9 that are exclusive for Nα-acetylation or Nα-methylation. We then employ eukaryotic cell models to probe the regulatory functions of these Nα-PTMs on MYL9. Our results show that, contrary to prevailing dogma, neither of these modifications regulate the stability of MYL9. Rather, exclusive Nα-acetylation promotes cytoplasmic roles of MYL9, while exclusive Nα-methylation promotes the nuclear role of MYL9 as a transcription factor. The increased cytoplasmic activity of Nα-acetylated MYL9 corresponds with increased phosphorylation at serine 19, a key MYL9 activating PTM. Increased nuclear activity of Nα-methylated MYL9 corresponds with increased DNA binding. Nα-methylation also results in a decrease of interactions between the N-terminus of MYL9 and a host of cytoskeletal proteins. These results confirm that Nα-acetylation and Nα-methylation differentially affect MYL9 function by creating distinct proteoforms with different internal PTM patterns and binding properties.
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27
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Faughn JD, Dean WL, Schaner Tooley CE. The N-terminal methyltransferase homologs NRMT1 and NRMT2 exhibit novel regulation of activity through heterotrimer formation. Protein Sci 2018; 27:1585-1599. [PMID: 30151928 DOI: 10.1002/pro.3456] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 06/07/2018] [Accepted: 06/08/2018] [Indexed: 12/13/2022]
Abstract
Protein, DNA, and RNA methyltransferases have an ever-expanding list of novel substrates and catalytic activities. Even within families and between homologs, it is becoming clear the intricacies of methyltransferase specificity and regulation are far more diverse than originally thought. In addition to specific substrates and distinct methylation levels, methyltransferase activity can be altered by complex formation with close homologs. We work with the N-terminal methyltransferase homologs NRMT1 and NRMT2. NRMT1 is a ubiquitously expressed distributive trimethylase. NRMT2 is a monomethylase expressed at low levels in a tissue-specific manner. They are both nuclear methyltransferases with overlapping consensus sequences but have distinct enzymatic activities and tissue expression patterns. Co-expression with NRMT2 increases the trimethylation rate of NRMT1, and here we aim to understand how this occurs. We use analytical ultracentrifugation to show that while NRMT1 primarily exists as a dimer and NRMT2 as a monomer, when co-expressed they form a heterotrimer. We use co-immunoprecipitation and molecular modeling to demonstrate in vivo binding and map areas of interaction. While overexpression of NRMT2 increases the half-life of NRMT1, the converse is not true, indicating that NRMT2 may be increasing NRMT1 activity by stabilizing the enzyme. Accordingly, the catalytic activity of NRMT2 is not needed to increase NRMT1 activity or increase its affinity for less preferred substrates. Monomethylation can also not rescue phenotypes seen with loss of trimethylation. Taken together, these data support a model where NRMT2 expression activates NRMT1 activity, not through priming, but by increasing its stability and substrate affinity.
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Affiliation(s)
- Jon D Faughn
- Department of Biochemistry and Molecular Genetics, University of Louisville School of Medicine, Louisville, Kentucky, 40202
| | - William L Dean
- Department of Biochemistry and Molecular Genetics, University of Louisville School of Medicine, Louisville, Kentucky, 40202
| | - Christine E Schaner Tooley
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, 14203
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28
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Jakobsson ME, Małecki JM, Halabelian L, Nilges BS, Pinto R, Kudithipudi S, Munk S, Davydova E, Zuhairi FR, Arrowsmith CH, Jeltsch A, Leidel SA, Olsen JV, Falnes PØ. The dual methyltransferase METTL13 targets N terminus and Lys55 of eEF1A and modulates codon-specific translation rates. Nat Commun 2018; 9:3411. [PMID: 30143613 PMCID: PMC6109062 DOI: 10.1038/s41467-018-05646-y] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 07/16/2018] [Indexed: 11/09/2022] Open
Abstract
Eukaryotic elongation factor 1 alpha (eEF1A) delivers aminoacyl-tRNA to the ribosome and thereby plays a key role in protein synthesis. Human eEF1A is subject to extensive post-translational methylation, but several of the responsible enzymes remain unknown. Using a wide range of experimental approaches, we here show that human methyltransferase (MTase)-like protein 13 (METTL13) contains two distinct MTase domains targeting the N terminus and Lys55 of eEF1A, respectively. Our biochemical and structural analyses provide detailed mechanistic insights into recognition of the eEF1A N terminus by METTL13. Moreover, through ribosome profiling, we demonstrate that loss of METTL13 function alters translation dynamics and results in changed translation rates of specific codons. In summary, we here unravel the function of a human MTase, showing that it methylates eEF1A and modulates mRNA translation in a codon-specific manner. Eukaryotic elongation factor 1 alpha (eEF1A) is subject to extensive post-translational methylation but not all responsible enzymes are known. Here, the authors identify METTL13 as an eEF1A methyltransferase with dual specificity, which is involved in the codon-specific modulation of mRNA translation.
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Affiliation(s)
- Magnus E Jakobsson
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0316, Oslo, Norway. .,Proteomics Program, Faculty of Health and Medical Sciences, Novo Nordisk Foundation Center for Protein Research (NNF-CPR), University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark.
| | - Jędrzej M Małecki
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0316, Oslo, Norway
| | - Levon Halabelian
- Structural Genomics Consortium, and Princess Margaret Cancer Centre, University of Toronto, Toronto, ON, M5G 2M9, Canada
| | - Benedikt S Nilges
- Max Planck Research Group for RNA Biology, Max Planck Institute for Molecular Biomedicine, 48149, Muenster, Germany.,Cells-in-Motion Cluster of Excellence, University of Muenster, 48149, Muenster, Germany
| | - Rita Pinto
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0316, Oslo, Norway
| | - Srikanth Kudithipudi
- Department of Biochemistry, Institute of Biochemistry and Technical Biochemistry, Stuttgart University, Allmandring 31, 70569, Stuttgart, Germany
| | - Stephanie Munk
- Proteomics Program, Faculty of Health and Medical Sciences, Novo Nordisk Foundation Center for Protein Research (NNF-CPR), University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Erna Davydova
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0316, Oslo, Norway
| | - Fawzi R Zuhairi
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0316, Oslo, Norway
| | - Cheryl H Arrowsmith
- Structural Genomics Consortium, and Princess Margaret Cancer Centre, University of Toronto, Toronto, ON, M5G 2M9, Canada
| | - Albert Jeltsch
- Department of Biochemistry, Institute of Biochemistry and Technical Biochemistry, Stuttgart University, Allmandring 31, 70569, Stuttgart, Germany
| | - Sebastian A Leidel
- Max Planck Research Group for RNA Biology, Max Planck Institute for Molecular Biomedicine, 48149, Muenster, Germany.,Cells-in-Motion Cluster of Excellence, University of Muenster, 48149, Muenster, Germany
| | - Jesper V Olsen
- Proteomics Program, Faculty of Health and Medical Sciences, Novo Nordisk Foundation Center for Protein Research (NNF-CPR), University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark.
| | - Pål Ø Falnes
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0316, Oslo, Norway.
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29
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Clarke SG. The ribosome: A hot spot for the identification of new types of protein methyltransferases. J Biol Chem 2018; 293:10438-10446. [PMID: 29743234 DOI: 10.1074/jbc.aw118.003235] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Cellular physiology depends on the alteration of protein structures by covalent modification reactions. Using a combination of bioinformatic, genetic, biochemical, and mass spectrometric approaches, it has been possible to probe ribosomal proteins from the yeast Saccharomyces cerevisiae for post-translationally methylated amino acid residues and for the enzymes that catalyze these modifications. These efforts have resulted in the identification and characterization of the first protein histidine methyltransferase, the first N-terminal protein methyltransferase, two unusual types of protein arginine methyltransferases, and a new type of cysteine methylation. Two of these enzymes may modify their substrates during ribosomal assembly because the final methylated histidine and arginine residues are buried deep within the ribosome with contacts only with RNA. Two of these modifications occur broadly in eukaryotes, including humans, whereas the others demonstrate a more limited phylogenetic range. Analysis of strains where the methyltransferase genes are deleted has given insight into the physiological roles of these modifications. These reactions described here add diversity to the modifications that generate the typical methylated lysine and arginine residues previously described in histones and other proteins.
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Affiliation(s)
- Steven G Clarke
- From the Department of Chemistry and Biochemistry and the Molecular Biology Institute, UCLA, Los Angeles, California 90095
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30
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Belov AM, Viner R, Santos MR, Horn DM, Bern M, Karger BL, Ivanov AR. Analysis of Proteins, Protein Complexes, and Organellar Proteomes Using Sheathless Capillary Zone Electrophoresis - Native Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2017; 28:2614-2634. [PMID: 28875426 PMCID: PMC5709234 DOI: 10.1007/s13361-017-1781-1] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 08/09/2017] [Accepted: 08/09/2017] [Indexed: 05/04/2023]
Abstract
Native mass spectrometry (MS) is a rapidly advancing field in the analysis of proteins, protein complexes, and macromolecular species of various types. The majority of native MS experiments reported to-date has been conducted using direct infusion of purified analytes into a mass spectrometer. In this study, capillary zone electrophoresis (CZE) was coupled online to Orbitrap mass spectrometers using a commercial sheathless interface to enable high-performance separation, identification, and structural characterization of limited amounts of purified proteins and protein complexes, the latter with preserved non-covalent associations under native conditions. The performance of both bare-fused silica and polyacrylamide-coated capillaries was assessed using mixtures of protein standards known to form non-covalent protein-protein and protein-ligand complexes. High-efficiency separation of native complexes is demonstrated using both capillary types, while the polyacrylamide neutral-coated capillary showed better reproducibility and higher efficiency for more complex samples. The platform was then evaluated for the determination of monoclonal antibody aggregation and for analysis of proteomes of limited complexity using a ribosomal isolate from E. coli. Native CZE-MS, using accurate single stage and tandem-MS measurements, enabled identification of proteoforms and non-covalent complexes at femtomole levels. This study demonstrates that native CZE-MS can serve as an orthogonal and complementary technique to conventional native MS methodologies with the advantages of low sample consumption, minimal sample processing and losses, and high throughput and sensitivity. This study presents a novel platform for analysis of ribosomes and other macromolecular complexes and organelles, with the potential for discovery of novel structural features defining cellular phenotypes (e.g., specialized ribosomes). Graphical Abstract ᅟ.
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Affiliation(s)
- Arseniy M Belov
- Barnett Institute of Chemical and Biological Analysis, Northeastern University, Boston, MA, 02115, USA
| | - Rosa Viner
- Thermo Fisher Scientific, San Jose, CA, 95134, USA
| | | | - David M Horn
- Thermo Fisher Scientific, San Jose, CA, 95134, USA
| | | | - Barry L Karger
- Barnett Institute of Chemical and Biological Analysis, Northeastern University, Boston, MA, 02115, USA
| | - Alexander R Ivanov
- Barnett Institute of Chemical and Biological Analysis, Northeastern University, Boston, MA, 02115, USA.
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31
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Gregorich ZR, Cai W, Lin Z, Chen AJ, Peng Y, Kohmoto T, Ge Y. Distinct sequences and post-translational modifications in cardiac atrial and ventricular myosin light chains revealed by top-down mass spectrometry. J Mol Cell Cardiol 2017; 107:13-21. [PMID: 28427997 DOI: 10.1016/j.yjmcc.2017.04.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 04/15/2017] [Indexed: 01/01/2023]
Abstract
Myosin is the principal component of the thick filaments that, through interactions with the actin thin filaments, mediates force production during muscle contraction. Myosin is a hexamer, consisting of two heavy chains, each associated with an essential (ELC) and a regulatory (RLC) light chain, which bind the lever-arm of the heavy chain and play important modulatory roles in striated muscle contraction. Nevertheless, a comprehensive assessment of the sequences of the ELC and RLC isoforms, as well as their post-translational modifications, in the heart remains lacking. Herein, utilizing top-down high-resolution mass spectrometry (MS), we have comprehensively characterized the sequences and N-terminal modifications of the atrial and ventricular isoforms of the myosin light chains from human and swine hearts, as well as the sites of phosphorylation in the swine proteins. In addition to the correction of disparities in the database sequences of the swine proteins, we show for the first time that, whereas the ventricular isoforms of the ELC and RLC are methylated at their N-termini, which is consistent with previous studies, the atrial isoforms of the ELC and RLC from both human and swine are Nα-methylated and Nα-acetylated, respectively. Furthermore, top-down MS with electron capture dissociation enabled localization of the sites of phosphorylation in swine RLC isoforms from the ventricles and atria to Ser14 and Ser22, respectively. Collectively, these results provide new insights into the sequences and modifications of myosin light chain isoforms in the human and swine hearts, which will pave the way for a better understanding of their functional roles in cardiac physiology and pathophysiology.
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Affiliation(s)
- Zachery R Gregorich
- Molecular and Cellular Pharmacology Training Program, University of Wisconsin-Madison, Madison, WI 53705, USA; Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Wenxuan Cai
- Molecular and Cellular Pharmacology Training Program, University of Wisconsin-Madison, Madison, WI 53705, USA; Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Ziqing Lin
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Albert J Chen
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Ying Peng
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Takushi Kohmoto
- Department of Surgery, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Ying Ge
- Molecular and Cellular Pharmacology Training Program, University of Wisconsin-Madison, Madison, WI 53705, USA; Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI 53705, USA; Human Proteomics Program, University of Wisconsin-Madison, Madison, WI 53705, USA; Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.
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32
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Wang Q, Wang K, Ye M. Strategies for large-scale analysis of non-histone protein methylation by LC-MS/MS. Analyst 2017; 142:3536-3548. [DOI: 10.1039/c7an00954b] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Protein methylation is an important post-translational modification (PTM) that plays crucial roles in the regulation of diverse biological processes.
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Affiliation(s)
- Qi Wang
- CAS Key Laboratory of Separation Sciences for Analytical Chemistry
- National Chromatographic R&A Center
- Dalian Institute of Chemical Physics
- Chinese Academy of Sciences
- Dalian
| | - Keyun Wang
- CAS Key Laboratory of Separation Sciences for Analytical Chemistry
- National Chromatographic R&A Center
- Dalian Institute of Chemical Physics
- Chinese Academy of Sciences
- Dalian
| | - Mingliang Ye
- CAS Key Laboratory of Separation Sciences for Analytical Chemistry
- National Chromatographic R&A Center
- Dalian Institute of Chemical Physics
- Chinese Academy of Sciences
- Dalian
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33
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Kou Q, Zhu B, Wu S, Ansong C, Tolić N, Paša-Tolić L, Liu X. Characterization of Proteoforms with Unknown Post-translational Modifications Using the MIScore. J Proteome Res 2016; 15:2422-32. [PMID: 27291504 DOI: 10.1021/acs.jproteome.5b01098] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Various proteoforms may be generated from a single gene due to primary structure alterations (PSAs) such as genetic variations, alternative splicing, and post-translational modifications (PTMs). Top-down mass spectrometry is capable of analyzing intact proteins and identifying patterns of multiple PSAs, making it the method of choice for studying complex proteoforms. In top-down proteomics, proteoform identification is often performed by searching tandem mass spectra against a protein sequence database that contains only one reference protein sequence for each gene or transcript variant in a proteome. Because of the incompleteness of the protein database, an identified proteoform may contain unknown PSAs compared with the reference sequence. Proteoform characterization is to identify and localize PSAs in a proteoform. Although many software tools have been proposed for proteoform identification by top-down mass spectrometry, the characterization of proteoforms in identified proteoform-spectrum matches still relies mainly on manual annotation. We propose to use the Modification Identification Score (MIScore), which is based on Bayesian models, to automatically identify and localize PTMs in proteoforms. Experiments showed that the MIScore is accurate in identifying and localizing one or two modifications.
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Affiliation(s)
- Qiang Kou
- Department of BioHealth Informatics, Indiana University-Purdue University Indianapolis , Indianapolis, Indiana 46202, United States
| | - Binhai Zhu
- Department of Computer Science, Montana State University , Bozeman, Montana 59717, United States
| | - Si Wu
- Department of Chemistry and Biochemistry, Univeristy of Oklahoma , Norman, Oklahoma 73019-5251, United States
| | | | | | | | - Xiaowen Liu
- Department of BioHealth Informatics, Indiana University-Purdue University Indianapolis , Indianapolis, Indiana 46202, United States.,Center for Computational Biology and Bioinformatics, Indiana University School of Medicine , Indianapolis, Indiana 46202-5122, United States
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34
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Loss of the N-terminal methyltransferase NRMT1 increases sensitivity to DNA damage and promotes mammary oncogenesis. Oncotarget 2016; 6:12248-63. [PMID: 25909287 PMCID: PMC4494936 DOI: 10.18632/oncotarget.3653] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Accepted: 02/27/2015] [Indexed: 12/31/2022] Open
Abstract
Though discovered over four decades ago, the function of N-terminal methylation has mostly remained a mystery. Our discovery of the first mammalian N-terminal methyltransferase, NRMT1, has led to the discovery of many new functions for N-terminal methylation, including regulation of DNA/protein interactions, accurate mitotic division, and nucleotide excision repair (NER). Here we test whether NRMT1 is also important for DNA double-strand break (DSB) repair, and given its previously known roles in cell cycle regulation and the DNA damage response, assay if NRMT1 is acting as a tumor suppressor. We find that NRMT1 knockdown significantly enhances the sensitivity of breast cancer cell lines to both etoposide treatment and γ-irradiation, as well as, increases proliferation rate, invasive potential, anchorage-independent growth, xenograft tumor size, and tamoxifen sensitivity. Interestingly, this positions NRMT1 as a tumor suppressor protein involved in multiple DNA repair pathways, and indicates, similar to BRCA1 and BRCA2, its loss may result in tumors with enhanced sensitivity to diverse DNA damaging chemotherapeutics.
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35
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Hamey JJ, Winter DL, Yagoub D, Overall CM, Hart-Smith G, Wilkins MR. Novel N-terminal and Lysine Methyltransferases That Target Translation Elongation Factor 1A in Yeast and Human. Mol Cell Proteomics 2015; 15:164-76. [PMID: 26545399 DOI: 10.1074/mcp.m115.052449] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Indexed: 01/22/2023] Open
Abstract
Eukaryotic elongation factor 1A (eEF1A) is an essential, highly methylated protein that facilitates translational elongation by delivering aminoacyl-tRNAs to ribosomes. Here, we report a new eukaryotic protein N-terminal methyltransferase, Saccharomyces cerevisiae YLR285W, which methylates eEF1A at a previously undescribed high-stoichiometry N-terminal site and the adjacent lysine. Deletion of YLR285W resulted in the loss of N-terminal and lysine methylation in vivo, whereas overexpression of YLR285W resulted in an increase of methylation at these sites. This was confirmed by in vitro methylation of eEF1A by recombinant YLR285W. Accordingly, we name YLR285W as elongation factor methyltransferase 7 (Efm7). This enzyme is a new type of eukaryotic N-terminal methyltransferase as, unlike the three other known eukaryotic N-terminal methyltransferases, its substrate does not have an N-terminal [A/P/S]-P-K motif. We show that the N-terminal methylation of eEF1A is also present in human; this conservation over a large evolutionary distance suggests it to be of functional importance. This study also reports that the trimethylation of Lys(79) in eEF1A is conserved from yeast to human. The methyltransferase responsible for Lys(79) methylation of human eEF1A is shown to be N6AMT2, previously documented as a putative N(6)-adenine-specific DNA methyltransferase. It is the direct ortholog of the recently described yeast Efm5, and we show that Efm5 and N6AMT2 can methylate eEF1A from either species in vitro. We therefore rename N6AMT2 as eEF1A-KMT1. Including the present work, yeast eEF1A is now documented to be methylated by five different methyltransferases, making it one of the few eukaryotic proteins to be extensively methylated by independent enzymes. This implies more extensive regulation of eEF1A by this posttranslational modification than previously appreciated.
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Affiliation(s)
- Joshua J Hamey
- From the ‡Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, New South Wales, 2052, Australia
| | - Daniel L Winter
- From the ‡Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, New South Wales, 2052, Australia
| | - Daniel Yagoub
- From the ‡Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, New South Wales, 2052, Australia
| | - Christopher M Overall
- §Centre for Blood Research, Departments of Oral Biological and Medical Sciences/Biochemistry and Molecular Biology, University of British Columbia, British Columbia, V6T 1Z4, Canada
| | - Gene Hart-Smith
- From the ‡Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, New South Wales, 2052, Australia
| | - Marc R Wilkins
- From the ‡Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, New South Wales, 2052, Australia;
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36
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Dong C, Mao Y, Tempel W, Qin S, Li L, Loppnau P, Huang R, Min J. Structural basis for substrate recognition by the human N-terminal methyltransferase 1. Genes Dev 2015; 29:2343-8. [PMID: 26543161 PMCID: PMC4691889 DOI: 10.1101/gad.270611.115] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 10/14/2015] [Indexed: 01/17/2023]
Abstract
α-N-terminal methylation represents a highly conserved and prevalent post-translational modification, yet its biological function has remained largely speculative. The recent discovery of α-N-terminal methyltransferase 1 (NTMT1) and its physiological substrates propels the elucidation of a general role of α-N-terminal methylation in mediating DNA-binding ability of the modified proteins. The phenotypes, observed from both NTMT1 knockdown in breast cancer cell lines and knockout mouse models, suggest the potential involvement of α-N-terminal methylation in DNA damage response and cancer development. In this study, we report the first crystal structures of human NTMT1 in complex with cofactor S-adenosyl-L-homocysteine (SAH) and six substrate peptides, respectively, and reveal that NTMT1 contains two characteristic structural elements (a β hairpin and an N-terminal extension) that contribute to its substrate specificity. Our complex structures, coupled with mutagenesis, binding, and enzymatic studies, also present the key elements involved in locking the consensus substrate motif XPK (X indicates any residue type other than D/E) into the catalytic pocket for α-N-terminal methylation and explain why NTMT1 prefers an XPK sequence motif. We propose a catalytic mechanism for α-N-terminal methylation. Overall, this study gives us the first glimpse of the molecular mechanism of α-N-terminal methylation and potentially contributes to the advent of therapeutic agents for human diseases associated with deregulated α-N-terminal methylation.
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Affiliation(s)
- Cheng Dong
- Structural Genomics Consortium, University of Toronto, Toronto, Ontaria M5G 1L7, Canada
| | - Yunfei Mao
- Department of Medicinal Chemistry, Drug Discovery and Development, Virginia Commonwealth University, Richmond, Virginia 23219, USA; The Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, Virginia 23219, USA
| | - Wolfram Tempel
- Structural Genomics Consortium, University of Toronto, Toronto, Ontaria M5G 1L7, Canada
| | - Su Qin
- Structural Genomics Consortium, University of Toronto, Toronto, Ontaria M5G 1L7, Canada
| | - Li Li
- Structural Genomics Consortium, University of Toronto, Toronto, Ontaria M5G 1L7, Canada
| | - Peter Loppnau
- Structural Genomics Consortium, University of Toronto, Toronto, Ontaria M5G 1L7, Canada
| | - Rong Huang
- Department of Medicinal Chemistry, Drug Discovery and Development, Virginia Commonwealth University, Richmond, Virginia 23219, USA; The Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, Virginia 23219, USA
| | - Jinrong Min
- Structural Genomics Consortium, University of Toronto, Toronto, Ontaria M5G 1L7, Canada; Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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37
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Marino G, Eckhard U, Overall CM. Protein Termini and Their Modifications Revealed by Positional Proteomics. ACS Chem Biol 2015; 10:1754-64. [PMID: 26042555 DOI: 10.1021/acschembio.5b00189] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A myriad of co- and post-translational modifications occur at protein N- and C-termini, resulting in an extra layer of proteome complexity and an additional source of protein regulation. Here, we review N- and C-terminal modifications and the contemporary positional proteomics techniques used to isolate protein terminal peptides from complex protein mixtures and characterize their diversity and occurrence in biological systems. Furthermore, these degradomics strategies--often referred to as N- and C-terminomics--represent dedicated high-throughput techniques to study proteolysis in dynamic living systems. Over the past decade, terminomics studies have provided indispensable information on the functional states of individual proteins, cell types, tissues, and biological processes and delivered fundamental new data for the Human Proteome Project, including high confidence identifications of many so-called "missing proteins", which had not been identified by traditional proteomics analyses.
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Affiliation(s)
- Giada Marino
- Centre
for Blood Research, Department of Oral Biological and Medical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Ulrich Eckhard
- Centre
for Blood Research, Department of Oral Biological and Medical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Christopher M. Overall
- Centre
for Blood Research, Department of Oral Biological and Medical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
- Department
of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
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38
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Lee BS, Shin S, Jeon JY, Jang KS, Lee BY, Choi S, Yoo TH. Incorporation of Unnatural Amino Acids in Response to the AGG Codon. ACS Chem Biol 2015; 10:1648-53. [PMID: 25946114 DOI: 10.1021/acschembio.5b00230] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The biological protein synthesis system has been engineered to incorporate unnatural amino acid into proteins, and this has opened up new routes for engineering proteins with novel compositions. While such systems have been successfully applied in research, there remains a need to develop new approaches with respect to the wider application of unnatural amino acids. In this study, we reported a strategy for incorporating unnatural amino acids into proteins by reassigning one of the Arg sense codons, the AGG codon. Using this method, several unnatural amino acids were quantitatively incorporated into the AGG site. Furthermore, we applied the method to multiple AGG sites, and even to tandem AGG sequences. The method developed and described here could be used for engineering proteins with diverse unnatural amino acids, particularly when employed in combination with other methods.
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Affiliation(s)
| | | | | | - Kyoung-Soon Jang
- Division
of Mass Spectrometry Research, Korea Basic Science Institute, 162
Yeongudanji-ro, Ochang-eup, Cheongwon-gu, Cheongju 363-883, Korea
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39
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Varland S, Osberg C, Arnesen T. N-terminal modifications of cellular proteins: The enzymes involved, their substrate specificities and biological effects. Proteomics 2015; 15:2385-401. [PMID: 25914051 PMCID: PMC4692089 DOI: 10.1002/pmic.201400619] [Citation(s) in RCA: 127] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 03/04/2015] [Accepted: 04/21/2015] [Indexed: 01/18/2023]
Abstract
The vast majority of eukaryotic proteins are N-terminally modified by one or more processing enzymes. Enzymes acting on the very first amino acid of a polypeptide include different peptidases, transferases, and ligases. Methionine aminopeptidases excise the initiator methionine leaving the nascent polypeptide with a newly exposed amino acid that may be further modified. N-terminal acetyl-, methyl-, myristoyl-, and palmitoyltransferases may attach an acetyl, methyl, myristoyl, or palmitoyl group, respectively, to the α-amino group of the target protein N-terminus. With the action of ubiquitin ligases, one or several ubiquitin molecules are transferred, and hence, constitute the N-terminal modification. Modifications at protein N-termini represent an important contribution to proteomic diversity and complexity, and are essential for protein regulation and cellular signaling. Consequently, dysregulation of the N-terminal modifying enzymes is implicated in human diseases. We here review the different protein N-terminal modifications occurring co- or post-translationally with emphasis on the responsible enzymes and their substrate specificities.
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Affiliation(s)
- Sylvia Varland
- Department of Molecular Biology, University of Bergen, Bergen, Norway
| | - Camilla Osberg
- Department of Molecular Biology, University of Bergen, Bergen, Norway.,Department of Surgery, Haukeland University Hospital, Bergen, Norway
| | - Thomas Arnesen
- Department of Molecular Biology, University of Bergen, Bergen, Norway.,Department of Surgery, Haukeland University Hospital, Bergen, Norway
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40
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Dai X, Rulten SL, You C, Caldecott KW, Wang Y. Identification and Functional Characterizations of N-Terminal α-N-Methylation and Phosphorylation of Serine 461 in Human Poly(ADP-ribose) Polymerase 3. J Proteome Res 2015; 14:2575-82. [PMID: 25886813 PMCID: PMC4703312 DOI: 10.1021/acs.jproteome.5b00126] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Poly(ADP-ribose) polymerase 3 (PARP3) is a member of the PARP family enzymes which catalyze the ADP-ribosylation of proteins. PARP3 plays an important role in DNA damage repair and mitotic progression. In this study, we identified, using mass spectrometric techniques, two novel post-translational modification sites in PARP3, α-N-methylation and phosphorylation of serine 461 (S461). We found that the N-terminal α-amino group of PARP3 is heavily methylated in human cells, and N-terminal RCC1 methyltransferase (NRMT) is a key enzyme required for this methylation. We also observed that the phosphorylation level of S461 in PARP3 could be reduced in human cells upon treatment with flavopiridol, a cyclin-dependent kinase inhibitor. Moreover, we demonstrated that S461 phosphorylation, but not α-N-methylation of PARP3, may be involved in the cellular response toward DNA double-strand breaks. These findings provide novel insights into the post-translational regulation of PARP3.
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Affiliation(s)
- Xiaoxia Dai
- Department of Chemistry, University of California, Riverside, California 92521-0403, United States
| | - Stuart L. Rulten
- Genome Damage and Stability Centre, University of Sussex, Falmer, Brighton BN1 9RQ, U.K
| | - Changjun You
- Department of Chemistry, University of California, Riverside, California 92521-0403, United States
| | - Keith W. Caldecott
- Genome Damage and Stability Centre, University of Sussex, Falmer, Brighton BN1 9RQ, U.K
| | - Yinsheng Wang
- Department of Chemistry, University of California, Riverside, California 92521-0403, United States
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41
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Drozak J, Piecuch M, Poleszak O, Kozlowski P, Chrobok L, Baelde HJ, de Heer E. UPF0586 Protein C9orf41 Homolog Is Anserine-producing Methyltransferase. J Biol Chem 2015; 290:17190-205. [PMID: 26001783 DOI: 10.1074/jbc.m115.640037] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Indexed: 01/25/2023] Open
Abstract
Anserine (β-alanyl-N(Pi)-methyl-L-histidine), a methylated derivative of carnosine (β-alanyl-L-histidine), is an abundant constituent of vertebrate skeletal muscles. Although it has been suggested to serve as a proton buffer and radical scavenger, its physiological function remains mysterious. The formation of anserine is catalyzed by carnosine N-methyltransferase, recently identified in chicken as histamine N-methyltransferase-like (HNMT-like) protein. Although the HNMT-like gene is absent in mammalian genomes, the activity of carnosine N-methyltransferase was reported in most mammalian species. In the present investigation, we purified carnosine N-methyltransferase from rat muscles about 2600-fold. Three polypeptides of ∼ 45, 50, and 70 kDa coeluting with the enzyme activity were identified in the preparation. Mass spectrometry analysis of these polypeptides resulted in the identification of UPF0586 protein C9orf41 homolog as the only meaningful candidate. Rat UPF0586 and its yeast, chicken, and human orthologs were expressed in COS-7 cells and purified to homogeneity. Although all recombinant proteins catalyzed the formation of anserine, as confirmed by chromatographic and mass spectrometry analysis, rat UPF0586 was more active on carnosine than other orthologs. Confocal microscopy of HeLa cells expressing recombinant UPF5086 proteins revealed their presence in both cytosol and nucleus. Carnosine and Gly-His were the best substrates for all UPF0586 orthologs studied, although the enzymes also methylated other l-histidine-containing di- and tripeptides. Finally, cotransfection of COS-7 cells with rat or human UPF0586 and carnosine synthase transformed the cells into efficient anserine producers. We conclude that UPF0586 is mammalian carnosine N-methyltransferase and hypothesize that it may also serve as a peptide or protein methyltransferase in eukaryotes.
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Affiliation(s)
| | | | | | - Piotr Kozlowski
- the Department of Molecular Biology, Institute of Biochemistry, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland
| | | | - Hans J Baelde
- the Department of Pathology, Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden, The Netherlands
| | - Emile de Heer
- the Department of Pathology, Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden, The Netherlands
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42
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Zhang G, Richardson SL, Mao Y, Huang R. Design, synthesis, and kinetic analysis of potent protein N-terminal methyltransferase 1 inhibitors. Org Biomol Chem 2015; 13:4149-54. [PMID: 25712161 PMCID: PMC4857722 DOI: 10.1039/c5ob00120j] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The protein N-terminal methyltransferase 1 (NTMT1) methylates the α-N-terminal amines of proteins. NTMT1 is upregulated in a variety of cancers and knockdown of NTMT1 results in cell mitotic defects. Therefore, NTMT1 inhibitors could be potential anticancer therapeutics. This study describes the design and synthesis of the first inhibitor targeting NTMT1. A novel bisubstrate analogue (NAM-TZ-SPKRIA) was shown to be a potent inhibitor (Ki = 0.20 μM) for NTMT1 and was selective versus protein lysine methyltransferase G9a and arginine methyltransferase 1. NAM-TZ-SPKRIA was found to exhibit a competitive inhibition pattern for both substrates, and mass spectrometry experiments revealed that the inhibitor substantially suppressed the methylation progression. Our results demonstrate the feasibility of using a triazole group to link an S-adenosyl-L-methionine analog with a peptide substrate to construct bisubstrate analogues as NTMT1 potent and selective inhibitors. This study lays a foundation to further discover small molecule NTMT1 inhibitors to interrogate its biological functions, and suggests a general strategy for the development of selective protein methyltransferase inhibitors.
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Affiliation(s)
- Gang Zhang
- Department of Medicinal Chemistry, and the Institute of Structural Biology & Drug Discovery, Virginia Commonwealth University, Richmond, VA, USA.
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43
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Bonsignore LA, Tooley JG, Van Hoose PM, Wang E, Cheng A, Cole MP, Schaner Tooley CE. NRMT1 knockout mice exhibit phenotypes associated with impaired DNA repair and premature aging. Mech Ageing Dev 2015; 146-148:42-52. [PMID: 25843235 DOI: 10.1016/j.mad.2015.03.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 03/17/2015] [Accepted: 03/30/2015] [Indexed: 12/11/2022]
Abstract
Though defective genome maintenance and DNA repair have long been known to promote phenotypes of premature aging, the role protein methylation plays in these processes is only now emerging. We have recently identified the first N-terminal methyltransferase, NRMT1, which regulates protein-DNA interactions and is necessary for both accurate mitotic division and nucleotide excision repair. To demonstrate if complete loss of NRMT1 subsequently resulted in developmental or aging phenotypes, we constructed the first NRMT1 knockout (Nrmt1(-/-)) mouse. The majority of these mice die shortly after birth. However, the ones that survive, exhibit decreased body size, female-specific infertility, kyphosis, decreased mitochondrial function, and early-onset liver degeneration; phenotypes characteristic of other mouse models deficient in DNA repair. The livers from Nrmt1(-/-) mice produce less reactive oxygen species (ROS) than wild type controls, and Nrmt1(-/-) mouse embryonic fibroblasts show a decreased capacity for handling oxidative damage. This indicates that decreased mitochondrial function may benefit Nrmt1(-/-) mice and protect them from excess internal ROS and subsequent DNA damage. These studies position the NRMT1 knockout mouse as a useful new system for studying the effects of genomic instability and defective DNA damage repair on organismal and tissue-specific aging.
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Affiliation(s)
- Lindsay A Bonsignore
- Department of Biochemistry & Molecular Genetics, Gheens Center on Aging, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - John G Tooley
- Department of Biochemistry & Molecular Genetics, Gheens Center on Aging, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Patrick M Van Hoose
- Department of Biochemistry & Molecular Genetics, Gheens Center on Aging, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Eugenia Wang
- Department of Biochemistry & Molecular Genetics, Gheens Center on Aging, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Alan Cheng
- Department of Biochemistry & Molecular Genetics, Gheens Center on Aging, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Marsha P Cole
- Department of Biochemistry & Molecular Genetics, Gheens Center on Aging, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Christine E Schaner Tooley
- Department of Biochemistry & Molecular Genetics, Gheens Center on Aging, University of Louisville School of Medicine, Louisville, KY 40202, USA.
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Richardson SL, Mao Y, Zhang G, Hanjra P, Peterson DL, Huang R. Kinetic mechanism of protein N-terminal methyltransferase 1. J Biol Chem 2015; 290:11601-10. [PMID: 25771539 DOI: 10.1074/jbc.m114.626846] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Indexed: 01/10/2023] Open
Abstract
The protein N-terminal methyltransferase 1 (NTMT1) catalyzes the transfer of the methyl group from the S-adenosyl-l-methionine to the protein α-amine, resulting in formation of S-adenosyl-l-homocysteine and α-N-methylated proteins. NTMT1 is an interesting potential anticancer target because it is overexpressed in gastrointestinal cancers and plays an important role in cell mitosis. To gain insight into the biochemical mechanism of NTMT1, we have characterized the kinetic mechanism of recombinant NTMT1 using a fluorescence assay and mass spectrometry. The results of initial velocity, product, and dead-end inhibition studies indicate that methylation by NTMT1 proceeds via a random sequential Bi Bi mechanism. In addition, our processivity studies demonstrate that NTMT1 proceeds via a distributive mechanism for multiple methylations. Together, our studies provide new knowledge about the kinetic mechanism of NTMT1 and lay the foundation for the development of mechanism-based inhibitors.
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Affiliation(s)
- Stacie L Richardson
- From the Department of Medicinal Chemistry, the Institute for Structural Biology and Drug Discovery, and
| | - Yunfei Mao
- From the Department of Medicinal Chemistry, the Institute for Structural Biology and Drug Discovery, and
| | - Gang Zhang
- From the Department of Medicinal Chemistry, the Institute for Structural Biology and Drug Discovery, and
| | - Pahul Hanjra
- From the Department of Medicinal Chemistry, the Institute for Structural Biology and Drug Discovery, and
| | - Darrell L Peterson
- the Institute for Structural Biology and Drug Discovery, and the Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, Virginia 23219
| | - Rong Huang
- From the Department of Medicinal Chemistry, the Institute for Structural Biology and Drug Discovery, and
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45
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Abstract
NRMT (N-terminal regulator of chromatin condensation 1 methyltransferase) was the first eukaryotic methyltransferase identified to specifically methylate the free α-amino group of proteins. Since the discovery of this N-terminal methyltransferase, many new substrates have been identified and the modification itself has been shown to regulate DNA-protein interactions. Sequence analysis predicts one close human homologue of NRMT, METTL11B (methyltransferase-like protein 11B, now renamed NRMT2). We show in the present paper for the first time that NRMT2 also has N-terminal methylation activity and recognizes the same N-terminal consensus sequences as NRMT (now NRMT1). Both enzymes have similar tissue expression and cellular localization patterns. However, enzyme assays and MS experiments indicate that they differ in their specific catalytic functions. Although NRMT1 is a distributive methyltransferase that can mono-, di- and tri-methylate its substrates, NRMT2 is primarily a monomethylase. Concurrent expression of NRMT1 and NRMT2 accelerates the production of trimethylation, and we propose that NRMT2 activates NRMT1 by priming its substrates for trimethylation.
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46
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Tooley JG, Schaner Tooley CE. New roles for old modifications: emerging roles of N-terminal post-translational modifications in development and disease. Protein Sci 2014; 23:1641-9. [PMID: 25209108 DOI: 10.1002/pro.2547] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 09/08/2014] [Indexed: 01/07/2023]
Abstract
The importance of internal post-translational modification (PTM) in protein signaling and function has long been known and appreciated. However, the significance of the same PTMs on the alpha amino group of N-terminal amino acids has been comparatively understudied. Historically considered static regulators of protein stability, additional functional roles for N-terminal PTMs are now beginning to be elucidated. New findings show that N-terminal methylation, along with N-terminal acetylation, is an important regulatory modification with significant roles in development and disease progression. There are also emerging studies on the enzymology and functional roles of N-terminal ubiquitylation and N-terminal propionylation. Here, will discuss the recent advances in the functional studies of N-terminal PTMs, recount the new N-terminal PTMs being identified, and briefly examine the possibility of dynamic N-terminal PTM exchange.
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Affiliation(s)
- John G Tooley
- Department of Biochemistry and Molecular Biology, James Graham Brown Cancer Center, University of Louisville School of Medicine, Louisville, Kentucky
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Cai Q, Fu L, Wang Z, Gan N, Dai X, Wang Y. α-N-methylation of damaged DNA-binding protein 2 (DDB2) and its function in nucleotide excision repair. J Biol Chem 2014; 289:16046-56. [PMID: 24753253 DOI: 10.1074/jbc.m114.558510] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
DDB2 exhibits a high affinity toward UV-damaged DNA, and it is involved in the initial steps of global genome nucleotide excision repair. Mutations in the DDB2 gene cause the genetic complementation group E of xeroderma pigmentosum, an autosomal recessive disease manifested clinically by hypersensitivity to sunlight exposure and an increased predisposition to skin cancer. Here we found that, in human cells, the initiating methionine residue in DDB2 was removed and that the N-terminal alanine could be methylated on its α-amino group in human cells, with trimethylation being the major form. We also demonstrated that the α-N-methylation of DDB2 is catalyzed by the N-terminal RCC1 methyltransferase. In addition, a methylation-defective mutant of DDB2 displayed diminished nuclear localization and was recruited at a reduced efficiency to UV-induced cyclobutane pyrimidine dimer foci. Moreover, loss of this methylation conferred compromised ATM (ataxia telangiectasia mutated) activation, decreased efficiency in cyclobutane pyrimidine dimer repair, and elevated sensitivity of cells toward UV light exposure. Our study provides new knowledge about the posttranslational regulation of DDB2 and expands the biological functions of protein α-N-methylation to DNA repair.
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Affiliation(s)
- Qian Cai
- From the Environmental Toxicology Graduate Program and
| | - Lijuan Fu
- From the Environmental Toxicology Graduate Program and
| | - Zi Wang
- From the Environmental Toxicology Graduate Program and
| | - Nanqin Gan
- Department of Chemistry, University of California, Riverside, California 92521-0403
| | - Xiaoxia Dai
- Department of Chemistry, University of California, Riverside, California 92521-0403
| | - Yinsheng Wang
- From the Environmental Toxicology Graduate Program and Department of Chemistry, University of California, Riverside, California 92521-0403
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Lanouette S, Mongeon V, Figeys D, Couture JF. The functional diversity of protein lysine methylation. Mol Syst Biol 2014; 10:724. [PMID: 24714364 PMCID: PMC4023394 DOI: 10.1002/msb.134974] [Citation(s) in RCA: 188] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Large‐scale characterization of post‐translational modifications (PTMs), such as phosphorylation, acetylation and ubiquitination, has highlighted their importance in the regulation of a myriad of signaling events. While high‐throughput technologies have tremendously helped cataloguing the proteins modified by these PTMs, the identification of lysine‐methylated proteins, a PTM involving the transfer of one, two or three methyl groups to the ε‐amine of a lysine side chain, has lagged behind. While the initial findings were focused on the methylation of histone proteins, several studies have recently identified novel non‐histone lysine‐methylated proteins. This review provides a compilation of all lysine methylation sites reported to date. We also present key examples showing the impact of lysine methylation and discuss the circuitries wired by this important PTM.
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Affiliation(s)
- Sylvain Lanouette
- Ottawa Institute of Systems Biology, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada
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49
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Homodimerization propensity of the intrinsically disordered N-terminal domain of Ultraspiracle from Aedes aegypti. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2014; 1844:1153-66. [PMID: 24704038 DOI: 10.1016/j.bbapap.2014.03.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2014] [Revised: 03/21/2014] [Accepted: 03/25/2014] [Indexed: 11/20/2022]
Abstract
The mosquito Aedes aegypti is the principal vector of dengue, one of the most devastating arthropod-borne viral infections in humans. The isoform specific A/B region, called the N-terminal domain (NTD), is hypervariable in sequence and length and is poorly conserved within the Ultraspiracle (Usp) family. The Usp protein together with ecdysteroid receptor (EcR) forms a heterodimeric complex. Up until now, there has been little data on the molecular properties of the isolated Usp-NTD. Here, we describe the biochemical and biophysical properties of the recombinant NTD of the Usp isoform B (aaUsp-NTD) from A. aegypti. These results, in combination with in silico bioinformatics approaches, indicate that aaUsp-NTD exhibits properties of an intrinsically disordered protein (IDP). We also present the first experimental evidence describing the dimerization propensity of the isolated NTD of Usp. These characteristics also appear for other members of the Usp family in different species, for example, in the Usp-NTD from Drosophila melanogaster and Bombyx mori. However, aaUsp-NTD exhibits the strongest homodimerization potential. We postulate that the unique dimerization of the NTD might be important for Usp function by providing an additional platform for interactions, in addition to the nuclear receptor superfamily dimerization via DNA binding domains and ligand binding domains that has already been extensively documented. Furthermore, the unique NTD-NTD interaction that was observed might contribute new insight into the dimerization propensities of nuclear receptors.
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50
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Kimura Y, Kurata Y, Ishikawa A, Okayama A, Kamita M, Hirano H. N-Terminal methylation of proteasome subunit Rpt1 in yeast. Proteomics 2013; 13:3167-74. [DOI: 10.1002/pmic.201300207] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 08/21/2013] [Accepted: 08/28/2013] [Indexed: 01/11/2023]
Affiliation(s)
- Yayoi Kimura
- Graduate School of Medical Life Science and Advanced Medical Research Center; Yokohama City University; Yokohama Japan
| | - Yoichi Kurata
- Graduate School of Medical Life Science and Advanced Medical Research Center; Yokohama City University; Yokohama Japan
| | - Akiyo Ishikawa
- Graduate School of Medical Life Science and Advanced Medical Research Center; Yokohama City University; Yokohama Japan
| | - Akiko Okayama
- Graduate School of Medical Life Science and Advanced Medical Research Center; Yokohama City University; Yokohama Japan
| | - Masahiro Kamita
- Graduate School of Medical Life Science and Advanced Medical Research Center; Yokohama City University; Yokohama Japan
| | - Hisashi Hirano
- Graduate School of Medical Life Science and Advanced Medical Research Center; Yokohama City University; Yokohama Japan
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