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James Sanford E, Bustamante Smolka M. A field guide to the proteomics of post-translational modifications in DNA repair. Proteomics 2022; 22:e2200064. [PMID: 35695711 PMCID: PMC9950963 DOI: 10.1002/pmic.202200064] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 05/19/2022] [Accepted: 05/30/2022] [Indexed: 12/15/2022]
Abstract
All cells incur DNA damage from exogenous and endogenous sources and possess pathways to detect and repair DNA damage. Post-translational modifications (PTMs), in the past 20 years, have risen to ineluctable importance in the study of the regulation of DNA repair mechanisms. For example, DNA damage response kinases are critical in both the initial sensing of DNA damage as well as in orchestrating downstream activities of DNA repair factors. Mass spectrometry-based proteomics revolutionized the study of the role of PTMs in the DNA damage response and has canonized PTMs as central modulators of nearly all aspects of DNA damage signaling and repair. This review provides a biologist-friendly guide for the mass spectrometry analysis of PTMs in the context of DNA repair and DNA damage responses. We reflect on the current state of proteomics for exploring new mechanisms of PTM-based regulation and outline a roadmap for designing PTM mapping experiments that focus on the DNA repair and DNA damage responses.
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Key Words
- LC-MS/MS, technology, bottom-up proteomics, technology, signal transduction, cell biology
- phosphoproteomics, technology, post-translational modification analysis, technology, post-translational modifications, cell biology, mass spectrometry
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Affiliation(s)
- Ethan James Sanford
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
| | - Marcus Bustamante Smolka
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853,Corresponding author:
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2
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Emenike B, Nwajiobi O, Raj M. Covalent Chemical Tools for Profiling Post-Translational Modifications. Front Chem 2022; 10:868773. [PMID: 35860626 PMCID: PMC9289218 DOI: 10.3389/fchem.2022.868773] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 05/30/2022] [Indexed: 12/05/2022] Open
Abstract
Nature increases the functional diversity of the proteome through posttranslational modifications (PTMs); a process that involves the proteolytic processing or catalytic attachment of diverse functional groups onto proteins. These modifications modulate a host of biological activities and responses. Consequently, anomalous PTMs often correlate to a host of diseases, hence there is a need to detect these transformations, both qualitatively and quantitatively. One technique that has gained traction is the use of robust chemical strategies to label different PTMs. By utilizing the intrinsic chemical reactivity of the different chemical groups on the target amino acid residues, this strategy can facilitate the delineation of the overarching and inclusionary roles of these different modifications. Herein, we will discuss the current state of the art in post-translational modification analysis, with a direct focus on covalent chemical methods used for detecting them.
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Small Mass but Strong Information: Diagnostic Ions Provide Crucial Clues to Correctly Identify Histone Lysine Modifications. Proteomes 2021; 9:proteomes9020018. [PMID: 33922761 PMCID: PMC8167651 DOI: 10.3390/proteomes9020018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/13/2021] [Accepted: 04/21/2021] [Indexed: 02/07/2023] Open
Abstract
(1) Background: The proteomic analysis of histones constitutes a delicate task due to the combination of two factors: slight variations in the amino acid sequences of variants and the multiplicity of post-translational modifications (PTMs), particularly those occurring on lysine residues. (2) Methods: To dissect the relationship between both aspects, we carefully evaluated PTM identification on lysine 27 from histone H3 (H3K27) and the artefactual chemical modifications that may lead to erroneous PTM determination. H3K27 is a particularly interesting example because it can bear a range of PTMs and it sits nearby residues 29 and 31 that vary between H3 sequence variants. We discuss how the retention times, neutral losses and immonium/diagnostic ions observed in the MS/MS spectra of peptides bearing modified lysines detectable in the low-mass region might help validate the identification of modified sequences. (3) Results: Diagnostic ions carry key information, thereby avoiding potential mis-identifications due to either isobaric PTM combinations or isobaric amino acid-PTM combinations. This also includes cases where chemical formylation or acetylation of peptide N-termini artefactually occurs during sample processing or simply in the timeframe of LC-MS/MS analysis. Finally, in the very subtle case of positional isomers possibly corresponding to a given mass of lysine modification, the immonium and diagnostic ions may allow the identification of the in vivo structure.
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4
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Bunkenborg J, Matthiesen R. Interpretation of Tandem Mass Spectra of Posttranslationally Modified Peptides. Methods Mol Biol 2020; 2051:199-230. [PMID: 31552630 DOI: 10.1007/978-1-4939-9744-2_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Tandem mass spectrometry provides a sensitive means of analyzing the amino acid sequence of peptides and modified peptides by providing accurate mass measurements of precursor and fragment ions. Modern mass spectrometry instrumentation is capable of rapidly generating many thousands of tandem mass spectra and protein database search engines have been developed to match the experimental data to peptide candidates. In most studies there is a schism between discarding perfectly valid data and including nonsensical peptide identifications-this is currently managed by establishing a false discovery rate (FDR) but for modified peptides it calls for an understanding of tandem mass spectrometry data. Manual evaluation of the data and perhaps experimental cross-checking of the MS data can save many months of experimental work trying to do biological follow-ups based on erroneous identifications. Especially for posttranslationally modified peptides there is a need for careful consideration of the data because search algorithms seldom have been optimized for the identification of modified peptides and because there are many pitfalls for the unwary. This chapter describes some of the issues that should be considered when interpreting and validating tandem mass spectra and gives some useful tables to aid in this process.
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Affiliation(s)
| | - Rune Matthiesen
- Computational and Experimental Biology Group, CEDOC, Chronic Diseases Research Centre, NOVA Medical School, Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Lisboa, Portugal
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5
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Zhang T, Zhang W, Liu L, Chen Y. Simultaneous detection of site-specific histone methylations and acetylation assisted by single template oriented molecularly imprinted polymers. Analyst 2020; 145:1376-1383. [DOI: 10.1039/c9an02360g] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A targeted proteomics assay combining single template oriented MIPs with LC-MS/MS for the simultaneous quantification of histone post-translational modification.
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Affiliation(s)
- Tianqi Zhang
- School of Pharmarcy, Nanjing Medical University
- Nanjing
- China
| | - Wen Zhang
- School of Pharmarcy, Nanjing Medical University
- Nanjing
- China
| | - Liang Liu
- School of Pharmarcy, Nanjing Medical University
- Nanjing
- China
| | - Yun Chen
- School of Pharmarcy, Nanjing Medical University
- Nanjing
- China
- State Key Laboratory of Reproductive Medicine
- China
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6
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Stadnik D, Bierczyńska-Krzysik A, Zielińska J, Antosik J, Borowicz P, Bednarek E, Bocian W, Sitkowski J, Kozerski L. Identification of Lysine Misincorporation at Asparagine Position in Recombinant Insulin Analogs Produced in E. coli. Pharm Res 2019; 36:79. [PMID: 30949841 PMCID: PMC6449291 DOI: 10.1007/s11095-019-2601-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 03/03/2019] [Indexed: 02/07/2023]
Abstract
PURPOSE Identification of human insulin analogs' impurity with a mass shift +14 Da in comparison to a parent protein. METHODS The protein sequence variant was detected and identified with the application of peptide mapping, liquid chromatography, tandem mass spectrometric analysis, nuclear magnetic resonance spectroscopy (NMR) and Edman sequencing. RESULTS The misincorporated lysine (Lys) at asparagine (Asn) position A21 was detected in recombinant human insulin and its analogs. CONCLUSIONS Although there are three asparagine residues in the insulin derivative, the misincorporation of lysine occurred only at position A21. The process involves G/U or A/U wobble base pairing.
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Affiliation(s)
- Dorota Stadnik
- Łukasiewicz Research Network - Institute of Biotechnology and Antibiotics, Starościńska 5, 02-516, Warsaw, Poland.
| | - Anna Bierczyńska-Krzysik
- Łukasiewicz Research Network - Institute of Biotechnology and Antibiotics, Starościńska 5, 02-516, Warsaw, Poland
| | - Joanna Zielińska
- Łukasiewicz Research Network - Institute of Biotechnology and Antibiotics, Starościńska 5, 02-516, Warsaw, Poland
| | - Jarosław Antosik
- Łukasiewicz Research Network - Institute of Biotechnology and Antibiotics, Starościńska 5, 02-516, Warsaw, Poland
| | - Piotr Borowicz
- Łukasiewicz Research Network - Institute of Biotechnology and Antibiotics, Starościńska 5, 02-516, Warsaw, Poland
| | - Elżbieta Bednarek
- National Medicines Institute, Chełmska 30/34, 00-725, Warsaw, Poland
| | - Wojciech Bocian
- National Medicines Institute, Chełmska 30/34, 00-725, Warsaw, Poland
| | - Jerzy Sitkowski
- National Medicines Institute, Chełmska 30/34, 00-725, Warsaw, Poland
| | - Lech Kozerski
- National Medicines Institute, Chełmska 30/34, 00-725, Warsaw, Poland
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7
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Aslebagh R, Wormwood KL, Channaveerappa D, Wetie AGN, Woods AG, Darie CC. Identification of Posttranslational Modifications (PTMs) of Proteins by Mass Spectrometry. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1140:199-224. [DOI: 10.1007/978-3-030-15950-4_11] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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8
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Diallo I, Seve M, Cunin V, Minassian F, Poisson JF, Michelland S, Bourgoin-Voillard S. Current trends in protein acetylation analysis. Expert Rev Proteomics 2018; 16:139-159. [PMID: 30580641 DOI: 10.1080/14789450.2019.1559061] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Acetylation is a widely occurring post-translational modification (PTM) of proteins that plays a crucial role in many cellular physiological and pathological processes. Over the last decade, acetylation analyses required the development of multiple methods to target individual acetylated proteins, as well as to cover a broader description of acetylated proteins that comprise the acetylome. Areas covered: This review discusses the different types of acetylation (N-ter/K-/O-acetylation) and then describes some major strategies that have been reported in the literature to detect, enrich, identify and quantify protein acetylation. The review highlights the advantages and limitations of these strategies, to guide researchers in designing their experimental investigations and analysis of protein acetylation. Finally, this review highlights the main applications of acetylomics (proteomics based on mass spectrometry) for understanding physiological and pathological conditions. Expert opinion: Recent advances in acetylomics have enhanced knowledge of the biological and pathological roles of protein acetylation and the acetylome. Besides, radiolabeling and western blotting remain also techniques-of-choice for targeted protein acetylation. Future challenges in acetylomics to analyze the N-ter and K-acetylome will most likely require enrichment/fractionation, MS instrumentation and bioinformatics. Challenges also remain to identify the potential biological roles of O-acetylation and cross-talk with other PTMs.
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Affiliation(s)
- Issa Diallo
- a Universite Grenoble Alpes - LBFA and BEeSy, PROMETHEE, Proteomic Platform , Saint-Martin-d'Heres , France.,b Inserm, U1055, PROMETHEE Proteomic Platform , Saint-Martin-d'Heres , France.,c CHU de Grenoble, Institut de Biologie et de Pathologie, PROMETHEE Proteomic Platform , La Tronche , France
| | - Michel Seve
- a Universite Grenoble Alpes - LBFA and BEeSy, PROMETHEE, Proteomic Platform , Saint-Martin-d'Heres , France.,b Inserm, U1055, PROMETHEE Proteomic Platform , Saint-Martin-d'Heres , France.,c CHU de Grenoble, Institut de Biologie et de Pathologie, PROMETHEE Proteomic Platform , La Tronche , France
| | - Valérie Cunin
- a Universite Grenoble Alpes - LBFA and BEeSy, PROMETHEE, Proteomic Platform , Saint-Martin-d'Heres , France.,b Inserm, U1055, PROMETHEE Proteomic Platform , Saint-Martin-d'Heres , France.,c CHU de Grenoble, Institut de Biologie et de Pathologie, PROMETHEE Proteomic Platform , La Tronche , France
| | | | | | - Sylvie Michelland
- a Universite Grenoble Alpes - LBFA and BEeSy, PROMETHEE, Proteomic Platform , Saint-Martin-d'Heres , France.,b Inserm, U1055, PROMETHEE Proteomic Platform , Saint-Martin-d'Heres , France.,c CHU de Grenoble, Institut de Biologie et de Pathologie, PROMETHEE Proteomic Platform , La Tronche , France
| | - Sandrine Bourgoin-Voillard
- a Universite Grenoble Alpes - LBFA and BEeSy, PROMETHEE, Proteomic Platform , Saint-Martin-d'Heres , France.,b Inserm, U1055, PROMETHEE Proteomic Platform , Saint-Martin-d'Heres , France.,c CHU de Grenoble, Institut de Biologie et de Pathologie, PROMETHEE Proteomic Platform , La Tronche , France
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9
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Greer SM, Sidoli S, Coradin M, Schack Jespersen M, Schwämmle V, Jensen ON, Garcia BA, Brodbelt JS. Extensive Characterization of Heavily Modified Histone Tails by 193 nm Ultraviolet Photodissociation Mass Spectrometry via a Middle-Down Strategy. Anal Chem 2018; 90:10425-10433. [PMID: 30063333 PMCID: PMC6383154 DOI: 10.1021/acs.analchem.8b02320] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The ability to map combinatorial patterns of post-translational modifications (PTMs) of proteins remains challenging for traditional bottom-up mass spectrometry workflows. There are also hurdles associated with top-down approaches related to limited data analysis options for heavily modified proteoforms. These shortcomings have accelerated interest in middle-down MS methods that focus on analysis of large peptides generated by specific proteases in conjunction with validated bioinformatics strategies to allow quantification of isomeric histoforms. Mapping multiple PTMs simultaneously requires the ability to obtain high sequence coverage to allow confident localization of the modifications, and 193 nm ultraviolet photodissociation (UVPD) has been shown to cause extensive fragmentation for large peptides and proteins. Histones are an ideal system to test the ability of UVPD to characterize multiple modifications, as the combinations of PTMs are the underpinning of the biological significance of histones and at the same time create an imposing challenge for characterization. The present study focuses on applying 193 nm UVPD to the identification and localization of PTMs on histones by UVPD and comparison to a popular alternative, electron-transfer dissociation (ETD), via a high-throughput middle-down LC/MS/MS strategy. Histone Coder and IsoScale, bioinformatics tools for verification of PTM assignments and quantification of histone peptides, were adapted for UVPD data and applied in the present study. In total, over 300 modified forms were identified, and the distributions of PTMs were quantified between UVPD and ETD. Significant differences in patterns of PTMs were found for histones from HeLa cells prior to and after treatment with a deacetylase inhibitor. Additional fragment ion types generated by UVPD proved essential for extensive characterization of the most heavily modified forms (>5 PTMs).
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Affiliation(s)
- Sylvester M Greer
- Department of Chemistry , University of Texas at Austin , Austin , Texas 78712 , United States
| | - Simone Sidoli
- Epigenetics Institute, Department of Biochemistry and Biophysics, Perelman School of Medicine , University of Pennsylvania , Philadelphia , Pennsylvania 19104 , United States
| | - Mariel Coradin
- Epigenetics Institute, Department of Biochemistry and Biophysics, Perelman School of Medicine , University of Pennsylvania , Philadelphia , Pennsylvania 19104 , United States
| | - Malena Schack Jespersen
- Department of Biochemistry and Molecular Biology , University of Southern Denmark , DK-5230 Odense , Denmark
| | - Veit Schwämmle
- Department of Biochemistry and Molecular Biology , University of Southern Denmark , DK-5230 Odense , Denmark
| | - Ole N Jensen
- Department of Biochemistry and Molecular Biology , University of Southern Denmark , DK-5230 Odense , Denmark
| | - Benjamin A Garcia
- Epigenetics Institute, Department of Biochemistry and Biophysics, Perelman School of Medicine , University of Pennsylvania , Philadelphia , Pennsylvania 19104 , United States
| | - Jennifer S Brodbelt
- Department of Chemistry , University of Texas at Austin , Austin , Texas 78712 , United States
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10
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Proteomic Analysis of Histone Variants and Their PTMs: Strategies and Pitfalls. Proteomes 2018; 6:proteomes6030029. [PMID: 29933573 PMCID: PMC6161106 DOI: 10.3390/proteomes6030029] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 06/04/2018] [Accepted: 06/13/2018] [Indexed: 12/14/2022] Open
Abstract
Epigenetic modifications contribute to the determination of cell fate and differentiation. The molecular mechanisms underlying histone variants and post-translational modifications (PTMs) have been studied in the contexts of development, differentiation, and disease. Antibody-based assays have classically been used to target PTMs, but these approaches fail to reveal combinatorial patterns of modifications. In addition, some histone variants are so similar to canonical histones that antibodies have difficulty distinguishing between these isoforms. Mass spectrometry (MS) has progressively developed as a powerful technology for the study of histone variants and their PTMs. Indeed, MS analyses highlighted exquisitely complex combinations of PTMs, suggesting “crosstalk” between them, and also revealed that PTM patterns are often variant-specific. Even though the sensitivity and acquisition speed of MS instruments have considerably increased alongside the development of computational tools for the study of multiple PTMs, it remains challenging to correctly describe the landscape of histone PTMs, and in particular to confidently assign modifications to specific amino acids. Here, we provide an inventory of MS-based strategies and of the pitfalls inherent to histone PTM and variant characterization, while stressing the complex interplay between PTMs and histone sequence variations. We will particularly illustrate the roles played by MS-based analyses in identifying and quantifying histone variants and modifications.
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11
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Cao J, Wang Q, Liu T, Peng N, Huang L. Insights into the post-translational modifications of archaeal Sis10b (Alba): lysine-16 is methylated, not acetylated, and this does not regulate transcription or growth. Mol Microbiol 2018; 109:192-208. [PMID: 29679495 DOI: 10.1111/mmi.13973] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/17/2018] [Indexed: 12/26/2022]
Abstract
Nucleic acid-binding proteins of the Sac10b family, also referred to as Alba (for acetylation lowers binding affinity), are highly conserved in Archaea. It was reported that Sso10b, a Sac10b homologue from Sulfolobus solfataricus, was acetylated at the ɛ-amino group of K16 and the α-amino group of the N-terminal residue. Notably, acetylation of K16 reduced the affinity of Sso10b for DNA and de-repressed transcription in vitro. Here, we show that Sis10b, a Sac10b homologue from Sulfolobus islandicus, underwent a range of post-translational modifications (PTMs). K16 in Sis10b as well as Sso10b was not acetylated. Substitution of K16 for R16, which resulted in the loss of the PTMs at the site, showed little effect on the growth of the cell and resulted in only a slight change in the expression of a very small fraction of the genes. The N-terminus of Sis10b was nearly completely Nα -acetylated. The reduction or loss of the terminal acetylation led to a significant increase in the cellular concentration of Sis10b, suggesting the involvement of the modification in the control of the turnover of the protein. These results have clarified the PTMs of Sac10b homologues and shed light on the proposed roles of acetylation of the protein.
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Affiliation(s)
- Jingjing Cao
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China.,College of Life Science, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Qian Wang
- Core Facility of Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China
| | - Tao Liu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
| | - Nan Peng
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
| | - Li Huang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China.,College of Life Science, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
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12
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Greer SM, Brodbelt JS. Top-Down Characterization of Heavily Modified Histones Using 193 nm Ultraviolet Photodissociation Mass Spectrometry. J Proteome Res 2018; 17:1138-1145. [DOI: 10.1021/acs.jproteome.7b00801] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Sylvester M. Greer
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Jennifer S. Brodbelt
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
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13
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Smith TE, Pond CD, Pierce E, Harmer ZP, Kwan J, Zachariah MM, Harper MK, Wyche TP, Matainaho TK, Bugni TS, Barrows LR, Ireland CM, Schmidt EW. Accessing chemical diversity from the uncultivated symbionts of small marine animals. Nat Chem Biol 2018; 14:179-185. [PMID: 29291350 PMCID: PMC5771842 DOI: 10.1038/nchembio.2537] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 11/09/2017] [Indexed: 12/15/2022]
Abstract
Chemistry drives many biological interactions between the microbiota and host animals, yet it is often challenging to identify the chemicals involved. This poses a problem, as such small molecules are excellent sources of potential pharmaceuticals, pretested by nature for animal compatibility. We discovered anti-HIV compounds from small, marine tunicates from the Eastern Fields of Papua New Guinea. Tunicates are a reservoir for novel bioactive chemicals, yet their small size often impedes identification or even detection of the chemicals within. We solved this problem by combining chemistry, metagenomics, and synthetic biology to directly identify and synthesize the natural products. We show that these anti-HIV compounds, the divamides, are a novel family of lanthipeptides produced by symbiotic bacteria living in the tunicate. Neighboring animal colonies contain structurally related divamides that differ starkly in their biological properties, suggesting a role for biosynthetic plasticity in a native context where biological interactions take place.
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Affiliation(s)
- Thomas E Smith
- Department of Medicinal Chemistry, University of Utah, Salt Lake City, Utah, USA
| | - Christopher D Pond
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah, USA
| | - Elizabeth Pierce
- Department of Medicinal Chemistry, University of Utah, Salt Lake City, Utah, USA
| | - Zachary P Harmer
- Department of Medicinal Chemistry, University of Utah, Salt Lake City, Utah, USA
| | - Jason Kwan
- Department of Medicinal Chemistry, University of Utah, Salt Lake City, Utah, USA
| | - Malcolm M Zachariah
- Department of Medicinal Chemistry, University of Utah, Salt Lake City, Utah, USA
| | - Mary Kay Harper
- Department of Medicinal Chemistry, University of Utah, Salt Lake City, Utah, USA
| | - Thomas P Wyche
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin, Madison, Wisconsin, USA
| | - Teatulohi K Matainaho
- Discipline of Pharmacology, School of Medicine and Health Sciences, University of Papua New Guinea, National Capital District 111, Papua New Guinea
| | - Tim S Bugni
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin, Madison, Wisconsin, USA
| | - Louis R Barrows
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah, USA
| | - Chris M Ireland
- Department of Medicinal Chemistry, University of Utah, Salt Lake City, Utah, USA
| | - Eric W Schmidt
- Department of Medicinal Chemistry, University of Utah, Salt Lake City, Utah, USA
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14
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Chen Z, Zhang G, Yang M, Li T, Ge F, Zhao J. Lysine Acetylome Analysis Reveals Photosystem II Manganese-stabilizing Protein Acetylation is Involved in Negative Regulation of Oxygen Evolution in Model Cyanobacterium Synechococcus sp. PCC 7002. Mol Cell Proteomics 2017; 16:1297-1311. [PMID: 28550166 PMCID: PMC5500762 DOI: 10.1074/mcp.m117.067835] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 05/09/2017] [Indexed: 12/11/2022] Open
Abstract
Nε-Acetylation of lysine residues represents a frequently occurring post-translational modification widespread in bacteria that plays vital roles in regulating bacterial physiology and metabolism. However, the role of lysine acetylation in cyanobacteria remains unclear, presenting a hurdle to in-depth functional study of this post-translational modification. Here, we report the lysine acetylome of Synechococcus sp. PCC 7002 (hereafter Synechococcus) using peptide prefractionation, immunoaffinity enrichment, and coupling with high-precision liquid chromatography-tandem mass spectrometry analysis. Proteomic analysis of Synechococcus identified 1653 acetylation sites on 802 acetylproteins involved in a broad range of biological processes. Interestingly, the lysine acetylated proteins were enriched for proteins involved in photosynthesis, for example. Functional studies of the photosystem II manganese-stabilizing protein were performed by site-directed mutagenesis and mutants mimicking either constitutively acetylated (K99Q, K190Q, and K219Q) or nonacetylated states (K99R, K190R, and K219R) were constructed. Mutation of the K190 acetylation site resulted in a distinguishable phenotype. Compared with the K190R mutant, the K190Q mutant exhibited a decreased oxygen evolution rate and an enhanced cyclic electron transport rate in vivo Our findings provide new insight into the molecular mechanisms of lysine acetylation that involved in the negative regulation of oxygen evolution in Synechococcus and creates opportunities for in-depth elucidation of the physiological role of protein acetylation in photosynthesis in cyanobacteria.
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Affiliation(s)
- Zhuo Chen
- From the ‡Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China
- §Key Lab of Plant Stress Research, College of Life Science, Shandong Normal University, Jinan 250014, Shandong, China
| | - Guiying Zhang
- From the ‡Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China
- ¶University of Chinese Academy of Sciences, Beijing 100094, China
| | - Mingkun Yang
- From the ‡Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China
| | - Tao Li
- From the ‡Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China;
| | - Feng Ge
- From the ‡Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China;
| | - Jindong Zhao
- From the ‡Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, China
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15
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Kwak HG, Suzuki T, Dohmae N. Global mapping of post-translational modifications on histone H3 variants in mouse testes. Biochem Biophys Rep 2017; 11:1-8. [PMID: 28955761 PMCID: PMC5614684 DOI: 10.1016/j.bbrep.2017.05.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 05/23/2017] [Indexed: 11/17/2022] Open
Abstract
Mass spectrometry (MS)-based characterization is important in proteomic research for verification of structural features and functional understanding of gene expression. Post-translational modifications (PTMs) such as methylation and acetylation have been reported to be associated with chromatin remodeling during spermatogenesis. Although antibody- and MS-based approaches have been applied for characterization of PTMs on H3 variants during spermatogenesis, variant-specific PTMs are still underexplored. We identified several lysine modifications in H3 variants, including testis-specific histone H3 (H3t), through their successful separation with MS-based strategy, based on differences in masses, retention times, and presence of immonium ions. Besides methylation and acetylation, we detected formylation as a novel PTM on H3 variants in mouse testes. These patterns were also observed in H3t. Our data provide high-throughput structural information about PTMs on H3 variants in mouse testes and show possible applications of this strategy in future proteomic studies on histone PTMs. Various post-translational modifications in histone H3 variants were characterized in the mouse testes. We specifically identified similar modified patterns based on immonium ions. Novel modified lysines in testis-specific H3 histone, H3t, were verified. Our approach will be helpful for the discovery of other novel or specific modifications during spermatogenesis.
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Key Words
- DTT, dithiothreitol
- ESI-TRAP, electrospray TRAP
- FDR, false discovery rate
- H2SO4, sulfuric acid
- HCD, high-energy collision dissociation
- HFBA, heptafluorobutyric acid
- HPLC, high performance liquid chromatography
- ISD, in source decay
- MALDI, matrix-assisted laser desorption/ionization
- MS, mass spectrometry
- Mass spectrometry
- PTMs, post-translational modifications
- Post-translational modification
- RP, reverse phase
- SDS-PAGE, sodium dodecyl sulfate-polyacrylamide gel electrophoresis
- Spermatogenesis
- TCA, trichloroacetic acid
- TFA, trifluoroacetic acid
- Testis-specific H3 histone
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16
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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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17
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Sayegh RSR, Batista IDFC, de Melo RL, Riske KA, Daffre S, Montich G, da Silva Junior PI. Longipin: An Amyloid Antimicrobial Peptide from the Harvestman Acutisoma longipes (Arachnida: Opiliones) with Preferential Affinity for Anionic Vesicles. PLoS One 2016; 11:e0167953. [PMID: 27997568 PMCID: PMC5172563 DOI: 10.1371/journal.pone.0167953] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 11/22/2016] [Indexed: 12/24/2022] Open
Abstract
In contrast to vertebrate immune systems, invertebrates lack an adaptive response and rely solely on innate immunity in which antimicrobial peptides (AMPs) play an essential role. Most of them are membrane active molecules that are typically unstructured in solution and adopt secondary/tertiary structures upon binding to phospholipid bilayers. This work presents the first characterization of a constitutive AMP from the hemolymph of an Opiliones order animal: the harvestman Acutisoma longipes. This peptide was named longipin. It presents 18 aminoacid residues (SGYLPGKEYVYKYKGKVF) and a positive net charge at neutral pH. No similarity with other AMPs was observed. However, high sequence similarity with heme-lipoproteins from ticks suggested that longipin might be a protein fragment. The synthetic peptide showed enhanced antifungal activity against Candida guilliermondii and C. tropicalis yeasts (MIC: 3.8–7.5 μM) and did not interfered with VERO cells line viability at all concentrations tested (200–0.1 μM). This selectivity against microbial cells is related to the highest affinity of longipin for anionic charged vesicles (POPG:POPC) compared to zwitterionic ones (POPC), once microbial plasma membrane are generally more negatively charged compared to mammalian cells membrane. Dye leakage from carboxyfluorescein-loaded POPG:POPC vesicles suggested that longipin is a membrane active antimicrobial peptide and FT-IR spectroscopy showed that the peptide chain is mainly unstructured in solution or in the presence of POPC vesicles. However, upon binding to POPG:POPC vesicles, the FT-IR spectrum showed bands related to β-sheet and amyloid-like fibril conformations in agreement with thioflavin-T binding assays, indicating that longipin is an amyloid antimicrobial peptide.
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Affiliation(s)
- Raphael Santa Rosa Sayegh
- Programa Interunidades em Biotecnologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
- Laboratório Especial de Toxinologia Aplicada, Instituto Butantan, São Paulo, Brazil
- * E-mail: (RSSS); (PISJ)
| | - Isabel de Fátima Correia Batista
- Unidade de Sequenciamento de Proteínas e Peptídeos, Instituto Butantan, São Paulo, Brazil
- Laboratório de Bioquímica e Biofísica, Instituto Butantan, São Paulo, Brazil
| | - Robson Lopes de Melo
- Laboratório Especial de Toxinologia Aplicada, Instituto Butantan, São Paulo, Brazil
| | - Karin A. Riske
- Departamento de Biofísica, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Sirlei Daffre
- Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Guillermo Montich
- Centro de Investigaciones en Quimica Biológica de Córdoba (CIQUIBIC, UNC-CONICET), Departamento de Química Biológica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Pedro Ismael da Silva Junior
- Programa Interunidades em Biotecnologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
- Laboratório Especial de Toxinologia Aplicada, Instituto Butantan, São Paulo, Brazil
- * E-mail: (RSSS); (PISJ)
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18
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Ning Z, Star AT, Mierzwa A, Lanouette S, Mayne J, Couture JF, Figeys D. A charge-suppressing strategy for probing protein methylation. Chem Commun (Camb) 2016; 52:5474-7. [PMID: 27021271 DOI: 10.1039/c6cc00814c] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Methylation of arginine and lysine (RK) residues play essential roles in epigenetics and the regulation of gene expression. However, research in this area is often hindered by the lack of effective tools for probing the protein methylation. Here, we present an antibody-free strategy to capture protein methylation on RK residues by using chemical reactions to eliminate the charges on un-modified RK residues and peptide N-termini. Peptides containing methylated RK residues remain positively charged and are then enriched by strong cation exchange chromatography, followed by high-resolution mass spectrometry identification.
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Affiliation(s)
- Zhibin Ning
- Ottawa Institute of Systems Biology, Department of Biochemistry, Immunology and Microbiology, Faculty of Medicine, University of Ottawa, Ontario, Canada.
| | - Alexandra Therese Star
- Ottawa Institute of Systems Biology, Department of Biochemistry, Immunology and Microbiology, Faculty of Medicine, University of Ottawa, Ontario, Canada.
| | - Anna Mierzwa
- Ottawa Institute of Systems Biology, Department of Biochemistry, Immunology and Microbiology, Faculty of Medicine, University of Ottawa, Ontario, Canada.
| | - Sylvain Lanouette
- Ottawa Institute of Systems Biology, Department of Biochemistry, Immunology and Microbiology, Faculty of Medicine, University of Ottawa, Ontario, Canada.
| | - Janice Mayne
- Ottawa Institute of Systems Biology, Department of Biochemistry, Immunology and Microbiology, Faculty of Medicine, University of Ottawa, Ontario, Canada.
| | - Jean-Francois Couture
- Ottawa Institute of Systems Biology, Department of Biochemistry, Immunology and Microbiology, Faculty of Medicine, University of Ottawa, Ontario, Canada.
| | - Daniel Figeys
- Ottawa Institute of Systems Biology, Department of Biochemistry, Immunology and Microbiology, Faculty of Medicine, University of Ottawa, Ontario, Canada.
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19
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Kim MS, Zhong J, Pandey A. Common errors in mass spectrometry-based analysis of post-translational modifications. Proteomics 2016; 16:700-14. [PMID: 26667783 DOI: 10.1002/pmic.201500355] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 11/05/2015] [Accepted: 12/08/2015] [Indexed: 12/29/2022]
Abstract
Mass spectrometry (MS) is a powerful tool to analyze complex mixtures of proteins in a high-throughput fashion. Proteome analysis has already become a routine task in biomedical research with the emergence of proteomics core facilities in most research institutions. Post-translational modifications (PTMs) represent a mechanism by which complex biological processes are orchestrated dynamically at the systems level. MS is rapidly becoming popular to discover new modifications and novel sites of known PTMs, revolutionizing the current understanding of diverse signaling pathways and biological processes. However, MS-based analysis of PTMs has its own caveats and pitfalls that can lead to erroneous conclusions. Here, we review the most common errors in MS-based PTM analyses with the goal of adopting strategies that maximize correct interpretation in the context of biological questions that are being addressed. Finally, we provide suggestions that should help mass spectrometrists, bioinformaticians and biologists to perform and interpret MS-based PTM analyses more accurately.
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Affiliation(s)
- Min-Sik Kim
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jun Zhong
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Akhilesh Pandey
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Departments of Biological Chemistry, Pathology and Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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20
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Measurement of Histone Methylation Dynamics by One-Carbon Metabolic Isotope Labeling and High-energy Collisional Dissociation Methylation Signature Ion Detection. Sci Rep 2016; 6:31537. [PMID: 27530234 PMCID: PMC4987619 DOI: 10.1038/srep31537] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 07/21/2016] [Indexed: 02/07/2023] Open
Abstract
Accumulating evidence suggests that cellular metabolites and nutrition levels control epigenetic modifications, including histone methylation. However, it is not currently possible to measure the metabolic control of histone methylation. Here we report a novel detection method to monitor methyl transfer from serine to histones through the one-carbon metabolic pathway, using stable-isotope labeling and detection of lysine methylation signature ions generated in high-energy-dissociation (HCD) tandem mass spectrometry. This method is a long-needed tool to study the metabolic control of histone methylation.
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21
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Hart-Smith G, Yagoub D, Tay AP, Pickford R, Wilkins MR. Large Scale Mass Spectrometry-based Identifications of Enzyme-mediated Protein Methylation Are Subject to High False Discovery Rates. Mol Cell Proteomics 2015; 15:989-1006. [PMID: 26699799 DOI: 10.1074/mcp.m115.055384] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Indexed: 01/22/2023] Open
Abstract
All large scale LC-MS/MS post-translational methylation site discovery experiments require methylpeptide spectrum matches (methyl-PSMs) to be identified at acceptably low false discovery rates (FDRs). To meet estimated methyl-PSM FDRs, methyl-PSM filtering criteria are often determined using the target-decoy approach. The efficacy of this methyl-PSM filtering approach has, however, yet to be thoroughly evaluated. Here, we conduct a systematic analysis of methyl-PSM FDRs across a range of sample preparation workflows (each differing in their exposure to the alcohols methanol and isopropyl alcohol) and mass spectrometric instrument platforms (each employing a different mode of MS/MS dissociation). Through (13)CD3-methionine labeling (heavy-methyl SILAC) of Saccharomyces cerevisiae cells and in-depth manual data inspection, accurate lists of true positive methyl-PSMs were determined, allowing methyl-PSM FDRs to be compared with target-decoy approach-derived methyl-PSM FDR estimates. These results show that global FDR estimates produce extremely unreliable methyl-PSM filtering criteria; we demonstrate that this is an unavoidable consequence of the high number of amino acid combinations capable of producing peptide sequences that are isobaric to methylated peptides of a different sequence. Separate methyl-PSM FDR estimates were also found to be unreliable due to prevalent sources of false positive methyl-PSMs that produce high peptide identity score distributions. Incorrect methylation site localizations, peptides containing cysteinyl-S-β-propionamide, and methylated glutamic or aspartic acid residues can partially, but not wholly, account for these false positive methyl-PSMs. Together, these results indicate that the target-decoy approach is an unreliable means of estimating methyl-PSM FDRs and methyl-PSM filtering criteria. We suggest that orthogonal methylpeptide validation (e.g. heavy-methyl SILAC or its offshoots) should be considered a prerequisite for obtaining high confidence methyl-PSMs in large scale LC-MS/MS methylation site discovery experiments and make recommendations on how to reduce methyl-PSM FDRs in samples not amenable to heavy isotope labeling. Data are available via ProteomeXchange with the data identifier PXD002857.
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Affiliation(s)
- Gene Hart-Smith
- From the ‡New South Wales Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, and
| | - Daniel Yagoub
- From the ‡New South Wales Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, and
| | - Aidan P Tay
- From the ‡New South Wales Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, and
| | - Russell Pickford
- ‖Bioanalytical Mass Spectrometry Facility, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Marc R Wilkins
- From the ‡New South Wales Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, and
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22
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Abstract
How DNA damaged is formed, recognized, and repaired in chromatin is an area of intense study. To better understand the structure activity relationships of damaged chromatin, mono and dinucleosomes containing site-specific damage have been prepared and studied. This review will focus on the design, synthesis, and characterization of model systems of damaged chromatin for structural, physical, and enzymatic studies.
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23
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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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24
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Naresh Chary V, Sudarshana Reddy B, Kumar CD, Srinivas R, Prabhakar S. Characterization of N,N-dimethyl amino acids by electrospray ionization-tandem mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2015; 50:771-781. [PMID: 26259661 DOI: 10.1002/jms.3588] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 02/23/2015] [Accepted: 02/23/2015] [Indexed: 06/04/2023]
Abstract
Methylation is an essential metabolic process for a number of critical reactions in the body. Methyl groups are involved in the healthy function of the body life processes, by conducting methylation process involving specific enzymes. In these processes, various amino acids are methylated, and the occurrence of methylated amino acids in nature is diverse. Nowadays, mass-spectrometric-based identification of small molecules as biomarkers for diseases is a growing research. Although all dimethyl amino acids are metabolically important molecules, mass spectral data are available only for a few of them in the literature. In this study, we report synthesis and characterization of all dimethyl amino acids, by electrospray ionization-tandem mass spectrometry (MS/MS) experiments on protonated molecules. The MS/MS spectra of all the studied dimethyl amino acids showed preliminary loss of H2O + CO to form corresponding immonium ions. The other product ions in the spectra are highly characteristic of the methyl groups on the nitrogen and side chain of the amino acids. The amino acids, which are isomeric and isobaric with the studied dimethyl amino acids, gave distinctive MS/MS spectra. The study also included MS/MS analysis of immonium ions of dimethyl amino acids that provide information on side chain structure, and it is further tested to determine the N-terminal amino acid of the peptides.
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Affiliation(s)
- V Naresh Chary
- National Centre for Mass Spectrometry, CSIR-Indian Institute of Chemical Technology, Hyderabad, 500 007, Telangana, India
| | - B Sudarshana Reddy
- National Centre for Mass Spectrometry, CSIR-Indian Institute of Chemical Technology, Hyderabad, 500 007, Telangana, India
- Academy of Scientific and Innovative Research, CSIR-Indian Institute of Chemical Technology, Hyderabad, 500 007, Telangana, India
| | - Ch Dinesh Kumar
- National Centre for Mass Spectrometry, CSIR-Indian Institute of Chemical Technology, Hyderabad, 500 007, Telangana, India
| | - R Srinivas
- National Centre for Mass Spectrometry, CSIR-Indian Institute of Chemical Technology, Hyderabad, 500 007, Telangana, India
| | - S Prabhakar
- National Centre for Mass Spectrometry, CSIR-Indian Institute of Chemical Technology, Hyderabad, 500 007, Telangana, India
- Academy of Scientific and Innovative Research, CSIR-Indian Institute of Chemical Technology, Hyderabad, 500 007, Telangana, India
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25
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Chandra K, Naoum JN, Roy TK, Gilon C, Gerber RB, Friedler A. Mechanistic studies of malonic acid-mediated in situ acylation. Biopolymers 2015; 104:495-505. [PMID: 25846609 DOI: 10.1002/bip.22654] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 03/13/2015] [Accepted: 03/30/2015] [Indexed: 11/05/2022]
Abstract
We have previously introduced an easy to perform, cost-effective and highly efficient acetylation technique for solid phase synthesis (SPPS). Malonic acid is used as a precursor and the reaction proceeds via a reactive ketene that acetylates the target amine. Here we present a detailed mechanistic study of the malonic acid-mediated acylation. The influence of reaction conditions, peptide sequence and reagents was systematically studied. Our results show that the methodology can be successfully applied to different types of peptides and nonpeptidic molecules irrespective of their structure, sequence, or conformation. Using alkyl, phenyl, and benzyl malonic acid, we synthesized various acyl peptides with almost quantitative yields. The ketenes obtained from the different malonic acid derived precursors were characterized by in situ (1) H-NMR. The reaction proceeded in short reaction times and resulted in excellent yields when using uronium-based coupling agents, DIPEA as a base, DMF/DMSO/NMP as solvents, Rink amide/Wang/Merrifield resins, temperature of 20°C, pH 8-12 and 5 min preactivation at inert atmosphere. The reaction was unaffected by Lewis acids, transition metal ions, surfactants, or salt. DFT studies support the kinetically favorable concerted mechanism for CO2 and ketene formation that leads to the thermodynamically stable acylated products. We conclude that the malonic acid-mediated acylation is a general method applicable to various target molecules.
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Affiliation(s)
- Koushik Chandra
- Institute of Chemistry, The Hebrew University of Jerusalem, Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Johnny N Naoum
- Institute of Chemistry, The Hebrew University of Jerusalem, Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Tapta Kanchan Roy
- Institute of Chemistry, The Hebrew University of Jerusalem, Safra Campus, Givat Ram, Jerusalem, 91904, Israel.,The Fritz Haber Research Center, The Hebrew University of Jerusalem, Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Chaim Gilon
- Institute of Chemistry, The Hebrew University of Jerusalem, Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - R Benny Gerber
- Institute of Chemistry, The Hebrew University of Jerusalem, Safra Campus, Givat Ram, Jerusalem, 91904, Israel.,The Fritz Haber Research Center, The Hebrew University of Jerusalem, Safra Campus, Givat Ram, Jerusalem, 91904, Israel.,Department of Chemistry, University of California, Irvine, California, 92697
| | - Assaf Friedler
- Institute of Chemistry, The Hebrew University of Jerusalem, Safra Campus, Givat Ram, Jerusalem, 91904, Israel
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26
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Walpole TB, Palmer DN, Jiang H, Ding S, Fearnley IM, Walker JE. Conservation of complete trimethylation of lysine-43 in the rotor ring of c-subunits of metazoan adenosine triphosphate (ATP) synthases. Mol Cell Proteomics 2015; 14:828-40. [PMID: 25608518 PMCID: PMC4390263 DOI: 10.1074/mcp.m114.047456] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 01/13/2015] [Indexed: 11/06/2022] Open
Abstract
The rotors of ATP synthases turn about 100 times every second. One essential component of the rotor is a ring of hydrophobic c-subunits in the membrane domain of the enzyme. The rotation of these c-rings is driven by a transmembrane proton-motive force, and they turn against a surface provided by another membrane protein, known as subunit a. Together, the rotating c-ring and the static subunit a provide a pathway for protons through the membrane in which the c-ring and subunit a are embedded. Vertebrate and invertebrate c-subunits are well conserved. In the structure of the bovine F1-ATPase-c-ring subcomplex, the 75 amino acid c-subunit is folded into two transmembrane α-helices linked by a short loop. Each bovine rotor-ring consists of eight c-subunits with the N- and C-terminal α-helices forming concentric inner and outer rings, with the loop regions exposed to the phospholipid head-group region on the matrix side of the inner membrane. Lysine-43 is in the loop region and its ε-amino group is completely trimethylated. The role of this modification is unknown. If the trimethylated lysine-43 plays some important role in the functioning, assembly or degradation of the c-ring, it would be expected to persist throughout vertebrates and possibly invertebrates also. Therefore, we have carried out a proteomic analysis of c-subunits across representative species from different classes of vertebrates and from invertebrate phyla. In the twenty-nine metazoan species that have been examined, the complete methylation of lysine-43 is conserved, and it is likely to be conserved throughout the more than two million extant metazoan species. In unicellular eukaryotes and prokaryotes, when the lysine is conserved it is unmethylated, and the stoichiometries of c-subunits vary from 9-15. One possible role for the trimethylated residue is to provide a site for the specific binding of cardiolipin, an essential component of ATP synthases in mitochondria.
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Affiliation(s)
- Thomas B Walpole
- From the ‡Mitochondrial Biology Unit, Medical Research Council, Hills Road, Cambridge, CB2 0XY, United Kingdom and
| | - David N Palmer
- From the ‡Mitochondrial Biology Unit, Medical Research Council, Hills Road, Cambridge, CB2 0XY, United Kingdom and the §Agriculture and Life Sciences Faculty, Lincoln University, 7647, New Zealand
| | - Huibing Jiang
- From the ‡Mitochondrial Biology Unit, Medical Research Council, Hills Road, Cambridge, CB2 0XY, United Kingdom and the §Agriculture and Life Sciences Faculty, Lincoln University, 7647, New Zealand
| | - Shujing Ding
- From the ‡Mitochondrial Biology Unit, Medical Research Council, Hills Road, Cambridge, CB2 0XY, United Kingdom and
| | - Ian M Fearnley
- From the ‡Mitochondrial Biology Unit, Medical Research Council, Hills Road, Cambridge, CB2 0XY, United Kingdom and
| | - John E Walker
- From the ‡Mitochondrial Biology Unit, Medical Research Council, Hills Road, Cambridge, CB2 0XY, United Kingdom and
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27
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Timm T, Lenz C, Merkel D, Sadiffo C, Grabitzki J, Klein J, Lochnit G. Detection and site localization of phosphorylcholine-modified peptides by NanoLC-ESI-MS/MS using precursor ion scanning and multiple reaction monitoring experiments. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2015; 26:460-471. [PMID: 25487775 DOI: 10.1007/s13361-014-1036-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 10/17/2014] [Accepted: 10/22/2014] [Indexed: 06/04/2023]
Abstract
Phosphorylcholine (PC)-modified biomolecules like lipopolysaccharides, glycosphingolipids, and (glyco)proteins are widespread, highly relevant antigens of parasites, since this small hapten shows potent immunomodulatory capacity, which allows the establishment of long-lasting infections of the host. Especially for PC-modified proteins, structural data is rare because of the zwitterionic nature of the PC substituent, resulting in low sensitivities and unusual but characteristic fragmentation patterns. We have developed a targeted mass spectrometric approach using hybrid triple quadrupole/linear ion trap (QTRAP) mass spectrometry coupled to nanoflow chromatography for the sensitive detection of PC-modified peptides from complex proteolytic digests, and the localization of the PC-modification within the peptide backbone. In a first step, proteolytic digests are screened using precursor ion scanning for the marker ions of choline (m/z 104.1) and phosphorylcholine (m/z 184.1) to establish the presence of PC-modified peptides. Potential PC-modified precursors are then subjected to a second analysis using multiple reaction monitoring (MRM)-triggered product ion spectra for the identification and site localization of the modified peptides. The approach was first established using synthetic PC-modified synthetic peptides and PC-modified model digests. Following the optimization of key parameters, we then successfully applied the method to the detection of PC-peptides in the background of a proteolytic digest of a whole proteome. This methodological invention will greatly facilitate the detection of PC-substituted biomolecules and their structural analysis.
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Affiliation(s)
- Thomas Timm
- Protein Analytics, Institute of Biochemistry, Faculty of Medicine, Justus-Liebig-University Giessen, 35392, Giessen, Germany
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28
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Szewczak J, Bierczyńska-Krzysik A, Piejko M, Mak P, Stadnik D. Isolation and Characterization of Acetylated Derivative of Recombinant Insulin Lispro Produced in Escherichia coli. Pharm Res 2015; 32:2450-7. [PMID: 25663326 PMCID: PMC4452257 DOI: 10.1007/s11095-015-1637-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 01/21/2015] [Indexed: 11/18/2022]
Abstract
Purpose Insulin lispro is a rapid-acting insulin analogue produced by recombinant DNA technology. As a biosynthetic drug, the protein undergoes strict monitoring aiming for detection and characterization of impurities. The goal of this study was to isolate and identify a derivative of insulin lispro formed during biosynthesis. Methods For this purpose, ion exchange chromatography in combination with endoproteinase Glu-C digestion, MALDI-TOF/TOF mass spectrometry and Edman sequencing were employed. Results Ion exchange chromatography analysis of related proteins in development batches of recombinant insulin lispro revealed the existence of unknown derivative in excess of the assumed limit. Its molecular mass was 42 Da higher than the theoretical mass of Lys(B31) insulin lispro—one of the expected process-related intermediates. Endoproteinase Glu-C cleavage enabled indication of the modified peptide. Tandem mass spectrometry (MS/MS) allowed to explore the location and type of the modification. The 42 amu shift was present in the mass of y-type ions, while b-type ions were in agreement with theoretical values. It suggested that the modification is present on B31 lysine. Further inquiry revealed the presence of two diagnostic ions for lysine acetylation at m/z 143.1 and 126.1. In addition, the peptide was isolated and sequenced by Edman degradation. Standards of phenylthiohydantoin derivatives of N-ε-acetyl-L-lysine and N-ε-trimethyl-L-lysine, not available commercially, were synthesized in the laboratory. The retention time of the modified residue confirmed its identity as N-ε-acetyl-L-lysine. Conclusions The derivative of insulin lispro formed during biosynthesis of the drug was identified to be N-ε-acetyl-L-lysine (B31) insulin lispro.
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Affiliation(s)
- Joanna Szewczak
- Institute of Biotechnology and Antibiotics, Starościńska 5, 02-516, Warsaw, Poland
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29
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Mo R, Yang M, Chen Z, Cheng Z, Yi X, Li C, He C, Xiong Q, Chen H, Wang Q, Ge F. Acetylome analysis reveals the involvement of lysine acetylation in photosynthesis and carbon metabolism in the model cyanobacterium Synechocystis sp. PCC 6803. J Proteome Res 2015; 14:1275-86. [PMID: 25621733 DOI: 10.1021/pr501275a] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Cyanobacteria are the oldest known life form inhabiting Earth and the only prokaryotes capable of performing oxygenic photosynthesis. Synechocystis sp. PCC 6803 (Synechocystis) is a model cyanobacterium used extensively in research on photosynthesis and environmental adaptation. Posttranslational protein modification by lysine acetylation plays a critical regulatory role in both eukaryotes and prokaryotes; however, its extent and function in cyanobacteria remain unexplored. Herein, we performed a global acetylome analysis on Synechocystis through peptide prefractionation, antibody enrichment, and high accuracy LC-MS/MS analysis; identified 776 acetylation sites on 513 acetylated proteins; and functionally categorized them into an interaction map showing their involvement in various biological processes. Consistent with previous reports, a large fraction of the acetylation sites are present on proteins involved in cellular metabolism. Interestingly, for the first time, many proteins involved in photosynthesis, including the subunits of phycocyanin (CpcA, CpcB, CpcC, and CpcG) and allophycocyanin (ApcA, ApcB, ApcD, ApcE, and ApcF), were found to be lysine acetylated, suggesting that lysine acetylation may play regulatory roles in the photosynthesis process. Six identified acetylated proteins associated with photosynthesis and carbon metabolism were further validated by immunoprecipitation and Western blotting. Our data provide the first global survey of lysine acetylation in cyanobacteria and reveal previously unappreciated roles of lysine acetylation in the regulation of photosynthesis. The provided data set may serve as an important resource for the functional analysis of lysine acetylation in cyanobacteria and facilitate the elucidation of the entire metabolic networks and photosynthesis process in this model cyanobacterium.
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Affiliation(s)
- Ran Mo
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences , Wuhan 430072, China
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Atik AE, Hernandez O, Maître P, Yalcin T. Specific rearrangement reactions of acetylated lysine containing peptide bn (n = 4-7) ion series. JOURNAL OF MASS SPECTROMETRY : JMS 2014; 49:1290-1297. [PMID: 25476947 DOI: 10.1002/jms.3462] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 08/05/2014] [Accepted: 08/05/2014] [Indexed: 06/04/2023]
Abstract
Characterization of ε-N-acetylated lysine containing peptides, one of the most prominent post-translational modifications of proteins, is an important goal for tandem mass spectrometry experiments. A systematic study for the fragmentation reactions of b ions derived from ε-N-acetyllysine containing model octapeptides (KAc YAGFLVG and YAKAc GFLVG) has been examined in detail. Collision-induced dissociation (CID) mass spectra of bn (n = 4-7) fragments of ε-N-acetylated lysine containing peptides are compared with those of N-terminal acetylated and doubly acetylated (both ε-N and N-terminal) peptides, as well as acetyl-free peptides. Both direct and nondirect fragments are observed for acetyl-free and singly acetylated (ε-N or N-terminal) peptides. In the case of ε-N-acetylated lysine containing peptides, however, specific fragment ions (m/z 309, 456, 569 and 668) are observed in CID mass spectra of bn (n = 4-7) ions. The CID mass spectra of these four ions are shown to be identical to those of selected protonated C-terminal amidated peptides. On this basis, a new type of rearrangement chemistry is proposed to account for the formation of these fragment ions, which are specific for ε-N-acetylated lysine containing peptides. Consistent with the observation of nondirect fragments, it is proposed that the b ions undergo head-to-tail macrocyclization followed by ring opening. The proposed reaction pathway assumes that bn (n = 4-7) of ε-N-acetylated lysine containing peptides has a tendency to place the KAc residue at the C-terminal position after macrocyclization/reopening mechanism. Then, following the loss of CO, it is proposed that the marker ions are the result of the loss of an acetyllysine imine as a neutral fragment.
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Affiliation(s)
- A Emin Atik
- Department of Chemistry, Faculty of Science, Izmir Institute of Technology, 35430, Urla-Izmir, Turkey
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31
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Huang J, Wang F, Ye M, Zou H. Enrichment and separation techniques for large-scale proteomics analysis of the protein post-translational modifications. J Chromatogr A 2014; 1372C:1-17. [DOI: 10.1016/j.chroma.2014.10.107] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 10/31/2014] [Accepted: 10/31/2014] [Indexed: 12/16/2022]
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Karch KR, Zee BM, Garcia BA. High resolution is not a strict requirement for characterization and quantification of histone post-translational modifications. J Proteome Res 2014; 13:6152-9. [PMID: 25325711 PMCID: PMC4261946 DOI: 10.1021/pr500902f] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
![]()
Mass
spectrometry (MS) is a powerful tool to accurately identify and quantify
histone post-translational modifications (PTMs). High-resolution mass
analyzers have been regarded as essential for these PTM analyses because
the mass accuracy afforded is sufficient to differentiate trimethylation
versus acetylation (42.0470 and 42.0106 Da, respectively), whereas
lower-resolution mass analyzers cannot. Noting this limitation, we
sought to determine whether lower-resolution detectors are nonetheless
adequate for histone PTM analysis by comparing the low-resolution
LTQ Velos Pro with the high-resolution LTQ-Orbitrap Velos Pro. We
first determined that the optimal scan mode on the LTQ Velos Pro is
the Enhanced scan mode with respect to apparent resolution, number
of MS and MS/MS scans per run, and reproducibility of label-free quantifications.
We next compared the performance of the LTQ Velos Pro to the LTQ-Orbitrap
Velos Pro using the same criteria for comparison, and we found that
the main difference is that the LTQ-Orbitrap Velos Pro is able to
resolve the difference between acetylation and trimethylation while
the LTQ Velos Pro cannot. However, using heavy isotope labeled synthetic
peptide standards and retention time information enables confident
assignment of these modifications and comparable quantification between
the instruments. Therefore, lower-resolution instruments can confidently
be utilized for histone PTM analysis.
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Affiliation(s)
- Kelly R Karch
- Epigenetics Program, Department of Biochemistry and Biophysics, Smilow Center for Translational Research, Perelman School of Medicine, University of Pennsylvania , 3400 Civic Center Boulevard, Building 421, Philadelphia, Pennsylvania 19104-5157, United States
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Witchell TD, Eshghi A, Nally JE, Hof R, Boulanger MJ, Wunder EA, Ko AI, Haake DA, Cameron CE. Post-translational modification of LipL32 during Leptospira interrogans infection. PLoS Negl Trop Dis 2014; 8:e3280. [PMID: 25356675 PMCID: PMC4214626 DOI: 10.1371/journal.pntd.0003280] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2014] [Accepted: 09/19/2014] [Indexed: 01/08/2023] Open
Abstract
Background Leptospirosis, a re-emerging disease of global importance caused by pathogenic Leptospira spp., is considered the world's most widespread zoonotic disease. Rats serve as asymptomatic carriers of pathogenic Leptospira and are critical for disease spread. In such reservoir hosts, leptospires colonize the kidney, are shed in the urine, persist in fresh water and gain access to a new mammalian host through breaches in the skin. Methodology/Principal Findings Previous studies have provided evidence for post-translational modification (PTM) of leptospiral proteins. In the current study, we used proteomic analyses to determine the presence of PTMs on the highly abundant leptospiral protein, LipL32, from rat urine-isolated L. interrogans serovar Copenhageni compared to in vitro-grown organisms. We observed either acetylation or tri-methylation of lysine residues within multiple LipL32 peptides, including peptides corresponding to regions of LipL32 previously identified as epitopes. Intriguingly, the PTMs were unique to the LipL32 peptides originating from in vivo relative to in vitro grown leptospires. The identity of each modified lysine residue was confirmed by fragmentation pattern analysis of the peptide mass spectra. A synthetic peptide containing an identified tri-methylated lysine, which corresponds to a previously identified LipL32 epitope, demonstrated significantly reduced immunoreactivity with serum collected from leptospirosis patients compared to the peptide version lacking the tri-methylation. Further, a subset of the identified PTMs are in close proximity to the established calcium-binding and putative collagen-binding sites that have been identified within LipL32. Conclusions/Significance The exclusive detection of PTMs on lysine residues within LipL32 from in vivo-isolated L. interrogans implies that infection-generated modification of leptospiral proteins may have a biologically relevant function during the course of infection. Although definitive determination of the role of these PTMs must await further investigations, the reduced immune recognition of a modified LipL32 epitope suggests the intriguing possibility that LipL32 modification represents a novel mechanism of immune evasion within Leptospira. Leptospirosis, caused by pathogenic Leptospira spp., constitutes an increasing global public health threat. Humans are accidental hosts, and acquire the disease primarily from contact with water sources that have been contaminated with urine from infected animals. Rats are asymptomatic carriers of infection and are critical for disease transmission to humans, particularly in urban slum environments. In this study, investigation of Leptospira directly isolated from the urine of infected rats showed acetylation or tri-methylation of the highly abundant leptospiral lipoprotein, LipL32. In comparison, Leptospira grown in culture did not result in any LipL32 lysine modifications. A synthetic peptide derived from LipL32 that incorporated a tri-methylated lysine modification exhibited less reactivity with serum from leptospirosis patients compared to an unmodified version of the peptide, suggesting LipL32 modifications may alter protein recognition by the immune response. This study reports, for the first time, modification of a Leptospira protein during infection, and suggests these modifications may have a functional consequence that contributes to bacterial persistence during infection.
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Affiliation(s)
- Timothy D. Witchell
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Azad Eshghi
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Jarlath E. Nally
- School of Veterinary Medicine, University College Dublin, Belfield, Dublin, Ireland
| | - Rebecca Hof
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Martin J. Boulanger
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Elsio A. Wunder
- Department of Epidemiology of Microbial Disease, Yale School of Public Health, New Haven, Connecticut, United States of America
- Gonçalo Moniz Research Center, Oswaldo Cruz Foundation, Brazilian Ministry of Health, Salvador, Brazil
| | - Albert I. Ko
- Department of Epidemiology of Microbial Disease, Yale School of Public Health, New Haven, Connecticut, United States of America
- Gonçalo Moniz Research Center, Oswaldo Cruz Foundation, Brazilian Ministry of Health, Salvador, Brazil
| | - David A. Haake
- Division of Infectious Diseases, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California, United States of America
- Department of Medicine, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California, United States of America
| | - Caroline E. Cameron
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
- * E-mail:
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Pentakota SK, Sandhya S, P Sikarwar A, Chandra N, Satyanarayana Rao MR. Mapping post-translational modifications of mammalian testicular specific histone variant TH2B in tetraploid and haploid germ cells and their implications on the dynamics of nucleosome structure. J Proteome Res 2014; 13:5603-17. [PMID: 25252820 DOI: 10.1021/pr500597a] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Histones regulate a variety of chromatin templated events by their post-translational modifications (PTMs). Although there are extensive reports on the PTMs of canonical histones, the information on the histone variants remains very scanty. Here, we report the identification of different PTMs, such as acetylation, methylation, and phosphorylation of a major mammalian histone variant TH2B. Our mass spectrometric analysis has led to the identification of both conserved and unique modifications across tetraploid spermatocytes and haploid spermatids. We have also computationally derived the 3-dimensional model of a TH2B containing nucleosome in order to study the spatial orientation of the PTMs identified and their effect on nucleosome stability and DNA binding potential. From our nucleosome model, it is evident that substitution of specific amino acid residues in TH2B results in both differential histone-DNA and histone-histone contacts. Furthermore, we have also observed that acetylation on the N-terminal tail of TH2B weakens the interactions with the DNA. These results provide direct evidence that, similar to somatic H2B, the testis specific histone TH2B also undergoes multiple PTMs, suggesting the possibility of chromatin regulation by such covalent modifications in mammalian male germ cells.
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Affiliation(s)
- Satya Krishna Pentakota
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research , Bangalore, Karnataka 560064, India
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35
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Liu F, Yang M, Wang X, Yang S, Gu J, Zhou J, Zhang XE, Deng J, Ge F. Acetylome analysis reveals diverse functions of lysine acetylation in Mycobacterium tuberculosis. Mol Cell Proteomics 2014; 13:3352-66. [PMID: 25180227 DOI: 10.1074/mcp.m114.041962] [Citation(s) in RCA: 123] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The lysine acetylation of proteins is a reversible post-translational modification that plays a critical regulatory role in both eukaryotes and prokaryotes. Mycobacterium tuberculosis is a facultative intracellular pathogen and the causative agent of tuberculosis. Increasing evidence shows that lysine acetylation may play an important role in the pathogenesis of M. tuberculosis. However, only a few acetylated proteins of M. tuberculosis are known, presenting a major obstacle to understanding the functional roles of reversible lysine acetylation in this pathogen. We performed a global acetylome analysis of M. tuberculosis H37Ra by combining protein/peptide prefractionation, antibody enrichment, and LC-MS/MS. In total, we identified 226 acetylation sites in 137 proteins of M. tuberculosis H37Ra. The identified acetylated proteins were functionally categorized into an interaction map and shown to be involved in various biological processes. Consistent with previous reports, a large proportion of the acetylation sites were present on proteins involved in glycolysis/gluconeogenesis, the citrate cycle, and fatty acid metabolism. A NAD(+)-dependent deacetylase (MRA_1161) deletion mutant of M. tuberculosis H37Ra was constructed and its characterization showed a different colony morphology, reduced biofilm formation, and increased tolerance of heat stress. Interestingly, lysine acetylation was found, for the first time, to block the immunogenicity of a peptide derived from a known immunogen, HspX, suggesting that lysine acetylation plays a regulatory role in immunogenicity. Our data provide the first global survey of lysine acetylation in M. tuberculosis. The dataset should be an important resource for the functional analysis of lysine acetylation in M. tuberculosis and facilitate the clarification of the entire metabolic networks of this life-threatening pathogen.
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Affiliation(s)
- Fengying Liu
- From the ‡Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Mingkun Yang
- §Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Xude Wang
- From the ‡Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Shanshan Yang
- From the ‡Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Jing Gu
- From the ‡Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Jie Zhou
- ¶Foshan Fourth People's Hospital, Foshan, China
| | - Xian-En Zhang
- ‖National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Jiaoyu Deng
- From the ‡Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China;
| | - Feng Ge
- §Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China;
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36
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Kelstrup CD, Frese C, Heck AJR, Olsen JV, Nielsen ML. Analytical utility of mass spectral binning in proteomic experiments by SPectral Immonium Ion Detection (SPIID). Mol Cell Proteomics 2014; 13:1914-24. [PMID: 24895383 PMCID: PMC4125726 DOI: 10.1074/mcp.o113.035915] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Unambiguous identification of tandem mass spectra is a cornerstone in mass-spectrometry-based proteomics. As the study of post-translational modifications (PTMs) by means of shotgun proteomics progresses in depth and coverage, the ability to correctly identify PTM-bearing peptides is essential, increasing the demand for advanced data interpretation. Several PTMs are known to generate unique fragment ions during tandem mass spectrometry, the so-called diagnostic ions, which unequivocally identify a given mass spectrum as related to a specific PTM. Although such ions offer tremendous analytical advantages, algorithms to decipher MS/MS spectra for the presence of diagnostic ions in an unbiased manner are currently lacking. Here, we present a systematic spectral-pattern-based approach for the discovery of diagnostic ions and new fragmentation mechanisms in shotgun proteomics datasets. The developed software tool is designed to analyze large sets of high-resolution peptide fragmentation spectra independent of the fragmentation method, instrument type, or protease employed. To benchmark the software tool, we analyzed large higher-energy collisional activation dissociation datasets of samples containing phosphorylation, ubiquitylation, SUMOylation, formylation, and lysine acetylation. Using the developed software tool, we were able to identify known diagnostic ions by comparing histograms of modified and unmodified peptide spectra. Because the investigated tandem mass spectra data were acquired with high mass accuracy, unambiguous interpretation and determination of the chemical composition for the majority of detected fragment ions was feasible. Collectively we present a freely available software tool that allows for comprehensive and automatic analysis of analogous product ions in tandem mass spectra and systematic mapping of fragmentation mechanisms related to common amino acids.
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Affiliation(s)
- Christian D Kelstrup
- From the ‡Department of Proteomics, The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Faculty of Health Sciences, DK-2200 Copenhagen, Denmark
| | - Christian Frese
- §Biomolecular Mass Spectrometry and Proteomics Group, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584CH Utrecht, The Netherlands
| | - Albert J R Heck
- §Biomolecular Mass Spectrometry and Proteomics Group, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584CH Utrecht, The Netherlands
| | - Jesper V Olsen
- From the ‡Department of Proteomics, The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Faculty of Health Sciences, DK-2200 Copenhagen, Denmark
| | - Michael L Nielsen
- From the ‡Department of Proteomics, The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Faculty of Health Sciences, DK-2200 Copenhagen, Denmark;
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Tang H, Fang H, Yin E, Brasier AR, Sowers LC, Zhang K. Multiplexed parallel reaction monitoring targeting histone modifications on the QExactive mass spectrometer. Anal Chem 2014; 86:5526-34. [PMID: 24823915 DOI: 10.1021/ac500972x] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Histone acetylation and methylation play an important role in the regulation of gene expression. Irregular patterns of histone global acetylation and methylation have frequently been seen in various diseases. Quantitative analysis of these patterns is of high value for the evaluation of disease development and of outcomes from therapeutic treatment. Targeting histone acetylation and methylation by selected reaction monitoring (SRM) is one of the current quantitative methods. Here, we reported the use of the multiplexed parallel reaction monitoring (PRM) method on the QExactive mass spectrometer to target previously known lysine acetylation and methylation sites of histone H3 and H4 for the purpose of establishing precursor-product pairs for SRM. 55 modified peptides among which 29 were H3 K27/K36 modified peptides were detected from 24 targeted precursor ions included in the inclusion list. The identification was carried out directly from the trypsin digests of core histones that were separated without derivatization on a homemade capillary column packed with Waters YMC ODS-AQ reversed phase materials. Besides documenting the higher-energy c-trap dissociation (HCD) MS(2) spectra of previously known histone H3/H4 acetylated and methylated tryptic peptides, we identified novel H3 K18 methylation, H3 K27 monomethyl/acetyl duel modifications, H2B K23 acetylation, and H4 K20 acetylation in mammalian histones. The information gained from these experiments sets the foundation for quantification of histone modifications by targeted mass spectrometry methods directly from core histone samples.
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Affiliation(s)
- Hui Tang
- Department of Pharmacology, University of Texas Medical Branch , Galveston, Texas 77555, United States
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38
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Schwämmle V, Aspalter CM, Sidoli S, Jensen ON. Large scale analysis of co-existing post-translational modifications in histone tails reveals global fine structure of cross-talk. Mol Cell Proteomics 2014; 13:1855-65. [PMID: 24741113 DOI: 10.1074/mcp.o113.036335] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mass spectrometry (MS) is a powerful analytical method for the identification and quantification of co-existing post-translational modifications in histone proteins. One of the most important challenges in current chromatin biology is to characterize the relationships between co-existing histone marks, the order and hierarchy of their deposition, and their distinct biological functions. We developed the database CrossTalkDB to organize observed and reported co-existing histone marks as revealed by MS experiments of histone proteins and their derived peptides. Statistical assessment revealed sample-specific patterns for the co-frequency of histone post-translational modifications. We implemented a new method to identify positive and negative interplay between pairs of methylation and acetylation marks in proteins. Many of the detected features were conserved between different cell types or exist across species, thereby revealing general rules for cross-talk between histone marks. The observed features are in accordance with previously reported examples of cross-talk. We observed novel types of interplay among acetylated residues, revealing positive cross-talk between nearby acetylated sites but negative cross-talk for distant ones, and for discrete methylation states at Lys-9, Lys-27, and Lys-36 of histone H3, suggesting a more differentiated functional role of methylation beyond the general expectation of enhanced activity at higher methylation states.
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Affiliation(s)
- Veit Schwämmle
- From the Department of Biochemistry and Molecular Biology University of Southern Denmark Campusvej 55 DK-5230 Odense M, Denmark
| | - Claudia-Maria Aspalter
- From the Department of Biochemistry and Molecular Biology University of Southern Denmark Campusvej 55 DK-5230 Odense M, Denmark
| | - Simone Sidoli
- From the Department of Biochemistry and Molecular Biology University of Southern Denmark Campusvej 55 DK-5230 Odense M, Denmark
| | - Ole N Jensen
- From the Department of Biochemistry and Molecular Biology University of Southern Denmark Campusvej 55 DK-5230 Odense M, Denmark
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Moccand C, Boycheva S, Surriabre P, Tambasco-Studart M, Raschke M, Kaufmann M, Fitzpatrick TB. The pseudoenzyme PDX1.2 boosts vitamin B6 biosynthesis under heat and oxidative stress in Arabidopsis. J Biol Chem 2014; 289:8203-16. [PMID: 24505140 DOI: 10.1074/jbc.m113.540526] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Vitamin B6 is an indispensable compound for survival, well known as a cofactor for numerous central metabolic enzymes and more recently for playing a role in several stress responses, particularly in association with oxidative stress. Regulatory aspects for the use of the vitamin in these roles are not known. Here we show that certain plants carry a pseudoenzyme (PDX1.2), which is involved in regulating vitamin B6 biosynthesis de novo under stress conditions. Specifically, we demonstrate that Arabidopsis PDX1.2 enhances the activity of its catalytic paralogs by forming a heterododecameric complex. PDX1.2 is strongly induced by heat as well as singlet oxygen stress, concomitant with an enhancement of vitamin B6 production. Analysis of pdx1.2 knockdown lines demonstrates that boosting vitamin B6 content is dependent on PDX1.2, revealing that this pseudoenzyme acts as a positive regulator of vitamin B6 biosynthesis during such stress conditions in plants.
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Affiliation(s)
- Cyril Moccand
- From the Department of Botany and Plant Biology, University of Geneva, 1211 Geneva, Switzerland and
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40
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Abstract
Post-translational modifications of histones comprise an important part of epigenetic gene regulation. Mass spectrometry and immunochemical techniques are currently the methods of choice for identification and quantitation of known and novel histone modifications. While peptide-centric mass spectrometry is a well-established tool for identification and quantification of histone modifications, recent technological advances have allowed discrete modification patterns to be assessed on intact histones. Chromatin immunoprecipitation assays (ChIP and ChIP-on-chip) are currently gaining tremendous popularity and are used to explore gene-specific patterns of histone modifications on a genomic scale. In this review, we introduce the basic concepts and recent developments of mass spectrometry, as well as immunochemical techniques and their applications in the analysis of histone modifications.
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Affiliation(s)
- Morten Beck Trelle
- University of Southern Denmark, Center for Epigenetics & Department of Molecular Biology & Biochemistry, Odense M, Denmark.
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41
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Chandra K, Roy TK, Naoum JN, Gilon C, Gerber RB, Friedler A. A highly efficient in situ N-acetylation approach for solid phase synthesis. Org Biomol Chem 2014; 12:1879-84. [DOI: 10.1039/c3ob42096e] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In situ peptide acetylation.
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Affiliation(s)
- Koushik Chandra
- Institute of Chemistry
- The Hebrew University of Jerusalem
- Givat Ram, Israel
| | - Tapta Kanchan Roy
- Institute of Chemistry
- The Hebrew University of Jerusalem
- Givat Ram, Israel
- The Fritz Haber Research Center
- The Hebrew University of Jerusalem
| | - Johnny N. Naoum
- Institute of Chemistry
- The Hebrew University of Jerusalem
- Givat Ram, Israel
| | - Chaim Gilon
- Institute of Chemistry
- The Hebrew University of Jerusalem
- Givat Ram, Israel
| | - R. Benny Gerber
- Institute of Chemistry
- The Hebrew University of Jerusalem
- Givat Ram, Israel
- The Fritz Haber Research Center
- The Hebrew University of Jerusalem
| | - Assaf Friedler
- Institute of Chemistry
- The Hebrew University of Jerusalem
- Givat Ram, Israel
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42
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Dillinger S, Garea AV, Deutzmann R, Németh A. Analysis of histone posttranslational modifications from nucleolus-associated chromatin by mass spectrometry. Methods Mol Biol 2014; 1094:277-93. [PMID: 24162996 DOI: 10.1007/978-1-62703-706-8_22] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Chromatin is unevenly distributed within the eukaryote nucleus and it contributes to the formation of morphologically and functionally distinct substructures, called chromatin domains and nuclear bodies. Here we describe an approach to assess specific chromatin features, the histone posttranslational modifications (PTMs), of the largest nuclear sub-compartment, the nucleolus. In this chapter, methods for the isolation of nucleolus-associated chromatin from native or formaldehyde-fixed cells and the effect of experimental procedures on the outcome of mass spectrometry analysis of histone PTMs are compared.
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Affiliation(s)
- Stefan Dillinger
- Biochemistry Center Regensburg, University of Regensburg, Regensburg, Germany
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43
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Mass Spectrometric Analysis of Post-translational Modifications (PTMs) and Protein–Protein Interactions (PPIs). ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 806:205-35. [DOI: 10.1007/978-3-319-06068-2_9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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44
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Afjehi-Sadat L, Garcia BA. Comprehending dynamic protein methylation with mass spectrometry. Curr Opin Chem Biol 2013; 17:12-9. [PMID: 23333572 DOI: 10.1016/j.cbpa.2012.12.023] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Revised: 12/23/2012] [Accepted: 12/30/2012] [Indexed: 01/08/2023]
Abstract
Protein methylation is a post-translational modification (PTM) which modulates cellular and biological processes including transcription, RNA processing, protein interactions and protein dynamics. Methylation, catalyzed by highly specific methyltransferase enzymes, occurs on several amino acids including arginine, lysine, histidine and dicarboxylic amino acids like glutamate. Mass spectrometry (MS)-based techniques continue to be the methods of choice for the study of protein PTMs. These approaches are powerful and sensitive tools that have been used to identify, quantify and characterize protein methylation. In addition, metabolic labeling strategies can be coupled to MS detection in order to measure dynamic and differential in vivo protein methylation rates. In this review, different applications of mass spectrometry technologies and methods to study protein methylation are discussed.
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Affiliation(s)
- Leila Afjehi-Sadat
- Epigenetics Program, Perelman School of Medicine, University of Pennsylvania, 1009C Stellar-Chance Laboratories, 422 Curie Boulevard, Philadelphia, PA 19104, USA
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45
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Cloutier P, Lavallée-Adam M, Faubert D, Blanchette M, Coulombe B. A newly uncovered group of distantly related lysine methyltransferases preferentially interact with molecular chaperones to regulate their activity. PLoS Genet 2013; 9:e1003210. [PMID: 23349634 PMCID: PMC3547847 DOI: 10.1371/journal.pgen.1003210] [Citation(s) in RCA: 122] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Accepted: 11/14/2012] [Indexed: 01/01/2023] Open
Abstract
Methylation is a post-translational modification that can affect numerous features of proteins, notably cellular localization, turnover, activity, and molecular interactions. Recent genome-wide analyses have considerably extended the list of human genes encoding putative methyltransferases. Studies on protein methyltransferases have revealed that the regulatory function of methylation is not limited to epigenetics, with many non-histone substrates now being discovered. We present here our findings on a novel family of distantly related putative methyltransferases. Affinity purification coupled to mass spectrometry shows a marked preference for these proteins to associate with various chaperones. Based on the spectral data, we were able to identify methylation sites in substrates, notably trimethylation of K135 of KIN/Kin17, K561 of HSPA8/Hsc70 as well as corresponding lysine residues in other Hsp70 isoforms, and K315 of VCP/p97. All modification sites were subsequently confirmed in vitro. In the case of VCP, methylation by METTL21D was stimulated by the addition of the UBX cofactor ASPSCR1, which we show directly interacts with the methyltransferase. This stimulatory effect was lost when we used VCP mutants (R155H, R159G, and R191Q) known to cause Inclusion Body Myopathy with Paget's disease of bone and Fronto-temporal Dementia (IBMPFD) and/or familial Amyotrophic Lateral Sclerosis (ALS). Lysine 315 falls in proximity to the Walker B motif of VCP's first ATPase/D1 domain. Our results indicate that methylation of this site negatively impacts its ATPase activity. Overall, this report uncovers a new role for protein methylation as a regulatory pathway for molecular chaperones and defines a novel regulatory mechanism for the chaperone VCP, whose deregulation is causative of degenerative neuromuscular diseases. Methylation, or transfer of a single or multiple methyl groups (CH3), is one of many post-translational modifications that occur on proteins. Such modifications can, in turn, affect numerous aspects of a protein, notably cellular localization, turnover, activity, and molecular interactions. In addition to post-translational modifications, the structural organization of a protein or protein complex can also have a significant impact on its function and stability. A group of factors known as “molecular chaperones” aid newly synthesized proteins in reaching their native conformation or alternating between physiologically relevant states. We present here a new family of factors that promote methylation of chaperones and show that, at least in one case, this modification translates into a modulation in the activity of the substrate chaperone. Our results not only characterize the function of previously unknown gene products, uncover a new role for protein methylation as a regulatory pathway for chaperones, and define a novel regulatory mechanism for the chaperone VCP, whose deregulation is causative of neuromuscular diseases, but also suggest the existence of a post-translational modification code that regulates molecular chaperones. Further decrypting this “chaperone code” will help understanding how the functional organization of the proteome is orchestrated.
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Affiliation(s)
- Philippe Cloutier
- Institut de Recherches Cliniques de Montréal (IRCM), Montréal, Québec, Canada
| | - Mathieu Lavallée-Adam
- McGill Centre for Bioinformatics and School of Computer Science, McGill University, Montréal, Québec, Canada
| | - Denis Faubert
- Institut de Recherches Cliniques de Montréal (IRCM), Montréal, Québec, Canada
| | - Mathieu Blanchette
- McGill Centre for Bioinformatics and School of Computer Science, McGill University, Montréal, Québec, Canada
| | - Benoit Coulombe
- Institut de Recherches Cliniques de Montréal (IRCM), Montréal, Québec, Canada
- Department of Biochemistry, Université de Montréal, Montréal, Québec, Canada
- * E-mail:
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46
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Wetie AGN, Sokolowska I, Woods AG, Darie CC. Identification of Post-Translational Modifications by Mass Spectrometry. Aust J Chem 2013. [DOI: 10.1071/ch13144] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Proteins are the effector molecules of many cellular and biological processes and are thus very dynamic and flexible. Regulation of protein activity, structure, stability, and turnover is in part controlled by their post-translational modifications (PTMs). Common PTMs of proteins include phosphorylation, glycosylation, methylation, ubiquitination, acetylation, and oxidation. Understanding the biology of protein PTMs can help elucidate the mechanisms of many pathological conditions and provide opportunities for prevention, diagnostics, and treatment of these disorders. Prior to the era of proteomics, it was standard to use chemistry methods for the identification of protein modifications. With advancements in proteomic technologies, mass spectrometry has become the method of choice for the analysis of protein PTMs. In this brief review, we will highlight the biochemistry of PTMs with an emphasis on mass spectrometry.
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47
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Abstract
Tandem mass spectrometry provides a sensitive means of analyzing the amino acid sequence of peptides and modified peptides by providing accurate mass measurements of precursor and fragment ions. Modern mass spectrometry instrumentation is capable of rapidly generating many thousands of tandem mass spectra and protein database search engines have been developed to match the experimental data to peptide candidates. In most studies there is a schism between discarding perfectly valid data and including nonsensical peptide identifications-this is currently a major bottleneck in data-analysis and it calls for an understanding of tandem mass spectrometry data. Manual evaluation of the data and perhaps experimental cross-checking of the MS data can save many months of experimental work trying to do biological follow-ups based on erroneous identifications. Especially for posttranslationally modified peptides there is a need for manual validation of the data because search algorithms seldom have been optimized for the identification of modified peptides and because there are many pitfalls for the unwary. This chapter describes some of the issues that should be considered when interpreting and validating tandem mass spectra and gives some useful tables to aid this process.
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Fu L, Chen T, Xue G, Zu L, Fang W. Selective cleavage enhanced by acetylating the side chain of lysine. JOURNAL OF MASS SPECTROMETRY : JMS 2013; 48:128-134. [PMID: 23303756 DOI: 10.1002/jms.3136] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Revised: 10/24/2012] [Accepted: 10/26/2012] [Indexed: 06/01/2023]
Abstract
Selective cleavage is of great interest in mass spectrometry studies as it can help sequence identification by promoting simple fragmentation pattern of peptides and proteins. In this work, the collision-induced dissociation of peptides containing internal lysine and acetylated lysine residues were studied. The experimental and computational results revealed that multiple fragmentation pathways coexisted when the lysine residue was two amino acid residues away from N-terminal of the peptide. After acetylation of the lysine side-chain, b(n)+ ions were the most abundant primary fragment products and the Lys(Ac)-Gly amide bond became the dominant cleavage site via an oxazolone pathway. Acetylating the side-chain of lysine promoted the selective cleavage of Lys-Xxx amide bond and generated much more information of the peptide backbone sequence. The results re-evaluate the selective cleavage due to the lysine basic side-chain and provide information for studying the post-translational modification of proteins and other bio-molecules containing Lys residues.
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49
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Li KK, Luo C, Wang D, Jiang H, Zheng YG. Chemical and biochemical approaches in the study of histone methylation and demethylation. Med Res Rev 2012; 32:815-67. [PMID: 22777714 DOI: 10.1002/mrr.20228] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Histone methylation represents one of the most critical epigenetic events in DNA function regulation in eukaryotic organisms. Classic molecular biology and genetics tools provide significant knowledge about mechanisms and physiological roles of histone methyltransferases and demethylases in various cellular processes. In addition to this stream line, development and application of chemistry and chemistry-related techniques are increasingly involved in biological study, and offer information otherwise difficult to obtain by standard molecular biology methods. Herein, we review recent achievements and progress in developing and applying chemical and biochemical approaches in the study of histone methylation, including chromatin immunoprecipitation, chemical ligation, mass spectrometry, biochemical methylation and demethylation assays, and inhibitor development. These technological advances allow histone methylation to be studied from genome-wide level to molecular and atomic levels. With ChIP technology, information can be obtained about precise mapping of histone methylation patterns at specific promoters, genes, or other genomic regions. MS is particularly useful in detecting and analyzing methylation marks in histone and nonhistone protein substrates. Chemical approaches that permit site-specific incorporation of methyl groups into histone proteins greatly facilitate the investigation of biological impacts of methylation at individual modification sites. Discovery and design of selective organic inhibitors of histone methyltransferases and demethylases provide chemical probes to interrogate methylation-mediated cellular pathways. Overall, these chemistry-related technological advances have greatly improved our understanding of the biological functions of histone methylation in normal physiology and diseased states, and also are of great potential to translate basic epigenetics research into diagnostic and therapeutic applications in the clinic.
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Affiliation(s)
- Keqin Kathy Li
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui Jin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
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Schlottmann S, Erkizan HV, Barber-Rotenberg JS, Knights C, Cheema A, Uren A, Avantaggiati ML, Toretsky JA. Acetylation Increases EWS-FLI1 DNA Binding and Transcriptional Activity. Front Oncol 2012; 2:107. [PMID: 22973553 PMCID: PMC3435532 DOI: 10.3389/fonc.2012.00107] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 08/13/2012] [Indexed: 01/06/2023] Open
Abstract
Ewing Sarcoma (ES) is associated with a balanced chromosomal translocation that in most cases leads to the expression of the oncogenic fusion protein and transcription factor EWS-FLI1. EWS-FLI1 has been shown to be crucial for ES cell survival and tumor growth. However, its regulation is still enigmatic. To date, no functionally significant post-translational modifications of EWS-FLI1 have been shown. Since ES are sensitive to histone deacetylase inhibitors (HDI), and these inhibitors are advancing in clinical trials, we sought to identify if EWS-FLI1 is directly acetylated. We convincingly show acetylation of the C-terminal FLI1 (FLI1-CTD) domain, which is the DNA binding domain of EWS-FLI1. In vitro acetylation studies showed that acetylated FLI1-CTD has higher DNA binding activity than the non-acetylated protein. Over-expression of PCAF or treatment with HDI increased the transcriptional activity of EWS-FLI1, when co-expressed in Cos7 cells. However, our data that evaluates the acetylation of full-length EWS-FLI1 in ES cells remains unclear, despite creating acetylation specific antibodies to four potential acetylation sites. We conclude that EWS-FLI1 may either gain access to chromatin as a result of histone acetylation or undergo regulation by direct acetylation. These data should be considered when patients are treated with HDAC inhibitors. Further investigation of this phenomenon will reveal if this potential acetylation has an impact on tumor response.
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Affiliation(s)
- Silke Schlottmann
- Lombardi Comprehensive Cancer Center, Georgetown University Washington, DC, USA
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