1
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Fouque KJD, Miller SA, Pham K, Bhanu NV, Cintron-Diaz YL, Leyva D, Kaplan D, Voinov VG, Ridgeway ME, Park MA, Garcia BA, Fernandez-Lima F. Top-"Double-Down" Mass Spectrometry of Histone H4 Proteoforms: Tandem Ultraviolet-Photon and Mobility/Mass-Selected Electron Capture Dissociations. Anal Chem 2022; 94:15377-15385. [PMID: 36282112 PMCID: PMC11037235 DOI: 10.1021/acs.analchem.2c03147] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Post-translational modifications (PTMs) on intact histones play a major role in regulating chromatin dynamics and influence biological processes such as DNA transcription, replication, and repair. The nature and position of each histone PTM is crucial to decipher how this information is translated into biological response. In the present work, the potential of a novel tandem top-"double-down" approach─ultraviolet photodissociation followed by mobility and mass-selected electron capture dissociation and mass spectrometry (UVPD-TIMS-q-ECD-ToF MS/MS)─is illustrated for the characterization of HeLa derived intact histone H4 proteoforms. The comparison between q-ECD-ToF MS/MS spectra and traditional Fourier-transform-ion cyclotron resonance-ECD MS/MS spectra of a H4 standard showed a similar sequence coverage (∼75%) with significant faster data acquisition in the ToF MS/MS platform (∼3 vs ∼15 min). Multiple mass shifts (e.g., 14 and 42 Da) were observed for the HeLa derived H4 proteoforms for which the top-down UVPD and ECD fragmentation analysis were consistent in detecting the presence of acetylated PTMs at the N-terminus and Lys5, Lys8, Lys12, and Lys16 residues, as well as methylated, dimethylated, and trimethylated PTMs at the Lys20 residue with a high sequence coverage (∼90%). The presented top-down results are in good agreement with bottom-up TIMS ToF MS/MS experiments and allowed for additional description of PTMs at the N-terminus. The integration of a 213 nm UV laser in the present platform allowed for UVPD events prior to the ion mobility-mass precursor separation for collision-induced dissociation (CID)/ECD-ToF MS. Selected c305+ UVPD fragments, from different H4 proteoforms (e.g., Ac + Me2, 2Ac + Me2 and 3Ac + Me2), exhibited multiple IMS bands for which similar CID/ECD fragmentation patterns per IMS band pointed toward the presence of conformers, adopting the same PTM distribution, with a clear assignment of the PTM localization for each of the c305+ UVPD fragment H4 proteoforms. These results were consistent with the biological "zip" model, where acetylation proceeds in the Lys16 to Lys5 direction. This novel platform further enhances the structural toolbox with alternative fragmentation mechanisms (UVPD, CID, and ECD) in tandem with fast, high-resolution mobility separations and shows great promise for global proteoform analysis.
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Affiliation(s)
- Kevin Jeanne Dit Fouque
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, United States
| | - Samuel A. Miller
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, United States
| | - Khoa Pham
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, United States
| | - Natarajan V. Bhanu
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, United States
| | - Yarixa L. Cintron-Diaz
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, United States
| | - Dennys Leyva
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, United States
| | | | | | | | - Melvin A. Park
- Bruker Daltonics Inc., Billerica, MA 01821, United States
| | - Benjamin A. Garcia
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, United States
| | - Francisco Fernandez-Lima
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, United States
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2
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Jeanne Dit Fouque K, Kaplan D, Voinov VG, Holck FHV, Jensen ON, Fernandez-Lima F. Proteoform Differentiation using Tandem Trapped Ion Mobility, Electron Capture Dissociation, and ToF Mass Spectrometry. Anal Chem 2021; 93:9575-9582. [PMID: 34170114 DOI: 10.1021/acs.analchem.1c01735] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Comprehensive characterization of post-translationally modified histone proteoforms is challenging due to their high isobaric and isomeric content. Trapped ion mobility spectrometry (TIMS), implemented on a quadrupole/time-of-flight (Q-ToF) mass spectrometer, has shown great promise in discriminating isomeric complete histone tails. The absence of electron activated dissociation (ExD) in the current platform prevents the comprehensive characterization of unknown histone proteoforms. In the present work, we report for the first time the use of an electromagnetostatic (EMS) cell devised for nonergodic dissociation based on electron capture dissociation (ECD), implemented within a nESI-TIMS-Q-ToF mass spectrometer for the characterization of acetylated (AcK18 and AcK27) and trimethylated (TriMetK4, TriMetK9 and TriMetK27) complete histone tails. The integration of the EMS cell in a TIMS-q-TOF MS permitted fast mobility-selected top-down ECD fragmentation with near 10% efficiency overall. The potential of this coupling was illustrated using isobaric (AcK18/TriMetK4) and isomeric (AcK18/AcK27 and TriMetK4/TriMetK9) binary H3 histone tail mixtures, and the H3.1 TriMetK27 histone tail structural diversity (e.g., three IMS bands at z = 7+). The binary isobaric and isomeric mixtures can be separated in the mobility domain with RIMS > 100 and the nonergodic ECD fragmentation permitted the PTM localization (sequence coverage of ∼86%). Differences in the ECD patterns per mobility band of the z = 7+ H3 TriMetK27 molecular ions suggested that the charge location is responsible for the structural differences observed in the mobility domain. This coupling further enhances the structural toolbox with fast, high resolution mobility separations in tandem with nonergodic fragmentation for effective proteoform differentiation.
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Affiliation(s)
- Kevin Jeanne Dit Fouque
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States.,Biomolecular Sciences Institute, Florida International University, Miami, Florida 33199, United States
| | - Desmond Kaplan
- KapScience, LLC., Tewksbury, Massachusetts 01876, United States
| | - Valery G Voinov
- e-MSion, Inc., Corvallis, Oregon 97330, United States.,Linus Pauling Institute and Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331, United States
| | - Frederik H V Holck
- Department of Biochemistry & Molecular Biology and VILLUM Center for Bioanalytical Sciences, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Ole N Jensen
- Department of Biochemistry & Molecular Biology and VILLUM Center for Bioanalytical Sciences, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Francisco Fernandez-Lima
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States.,Biomolecular Sciences Institute, Florida International University, Miami, Florida 33199, United States
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3
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Mao H, Han G, Xu L, Zhu D, Lin H, Cao X, Yu Y, Chen CD. Cis-existence of H3K27me3 and H3K36me2 in mouse embryonic stem cells revealed by specific ions of isobaric modification chromatogram. Stem Cell Res Ther 2015. [PMID: 26194893 PMCID: PMC4533945 DOI: 10.1186/s13287-015-0131-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Introduction Histone H3 lysine 27 trimethylation (H3K27me3) and H3 lysine 36 trimethylation (H3K36me3) are important epigenetic modifications correlated with transcription repression and activation, respectively. These two opposing modifications rarely co-exist in the same H3 polypeptide. However, a small but significant amount of H3 tails are modified with 5 methyl groups on K27 and K36 in mouse embryonic stem cells (mESCs) and it is unclear how the trimethylation is distributed on K27 or K36. Methods A label-free, bottom-up mass spectrum method, named specific ions of isobaric modification chromatogram (SIMC), was established to quantify the relative abundance of K27me2-K36me3 and K27me3-K36me2 in the same histone H3 tail. Results By using this method, we demonstrated that the H3K27me3-K36me2 comprises about 85 % of the penta-methylated H3 tails at K27 and K36 in mESCs. Upon mESC differentiation, the abundance of H3K27me3-K36me2 significantly decreased, while the level of H3K27me2-K36me3 remains unchanged. Conclusion Our study not only revealed the cis-existence of H3K27me3-K36me2 in mESCs, but also suggested that this combinatorial histone modification may assume a specific regulatory function during differentiation. Electronic supplementary material The online version of this article (doi:10.1186/s13287-015-0131-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hailei Mao
- Department of Anesthesiology and Critical Care Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China. .,State Key Laboratory of Molecular Biology, and Shanghai Key laboratory of Molecular Andrology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, 200031, China.
| | - Gang Han
- State Key Laboratory of Molecular Biology, and Shanghai Key laboratory of Molecular Andrology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, 200031, China.
| | - Longyong Xu
- State Key Laboratory of Molecular Biology, and Shanghai Key laboratory of Molecular Andrology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, 200031, China.
| | - Duming Zhu
- Department of Anesthesiology and Critical Care Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China.
| | - Hanqing Lin
- State Key Laboratory of Molecular Biology, and Shanghai Key laboratory of Molecular Andrology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, 200031, China.
| | - Xiongwen Cao
- State Key Laboratory of Molecular Biology, and Shanghai Key laboratory of Molecular Andrology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, 200031, China.
| | - Yi Yu
- State Key Laboratory of Molecular Biology, and Shanghai Key laboratory of Molecular Andrology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, 200031, China.
| | - Charlie Degui Chen
- State Key Laboratory of Molecular Biology, and Shanghai Key laboratory of Molecular Andrology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, 200031, China.
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Katoh M. Functional proteomics of the epigenetic regulators ASXL1, ASXL2 and ASXL3: a convergence of proteomics and epigenetics for translational medicine. Expert Rev Proteomics 2015; 12:317-28. [PMID: 25835095 DOI: 10.1586/14789450.2015.1033409] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
ASXL1, ASXL2 and ASXL3 are epigenetic scaffolds for BAP1, EZH2, NCOA1, nuclear receptors and WTIP. Here, functional proteomics of the ASXL family members are reviewed with emphasis on mutation spectra, the ASXM2 domain and the plant homeodomain (PHD) finger. Copy number gains of ASXL1 occur in chromosome 20q11.2 duplication syndrome and cervical cancer. Truncation mutations of ASXLs occur in autism, Bohring-Opitz and related syndromes, hematological malignancies and solid tumors, such as prostate cancer, breast cancer and high-grade glioma, which are gain- or loss-of-function mutations. The ASXM2 domain is a binding module for androgen receptor and estrogen receptor α, while the PHD finger is a ligand of WTIP LIM domains and a putative chromatin-binding module. Phylogenetic analyses of 139 human PHD fingers revealed that ASXL PHD fingers cluster with those of BPTF, DIDO, ING1, KDM5A (JARID1A), KMT2E (MLL5), PHF2, PHF8 and PHF23. The cell context-dependent epigenetic code of ASXLs should be deciphered to develop therapeutics for human diseases.
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Affiliation(s)
- Masaru Katoh
- Department of Omics Network, National Cancer Center - Japan, 5-1-1 Tsukiji Chuo Ward, Tokyo 104-0045, Japan
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5
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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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6
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Soldi M, Bremang M, Bonaldi T. Biochemical systems approaches for the analysis of histone modification readout. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1839:657-68. [PMID: 24681439 DOI: 10.1016/j.bbagrm.2014.03.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 03/06/2014] [Accepted: 03/18/2014] [Indexed: 11/28/2022]
Abstract
Chromatin is the macromolecular nucleoprotein complex that governs the organization of genetic material in the nucleus of eukaryotic cells. In chromatin, DNA is packed with histone proteins into nucleosomes. Core histones are prototypes of hyper-modified proteins, being decorated by a large number of site-specific reversible and irreversible post-translational modifications (PTMs), which contribute to the maintenance and modulation of chromatin plasticity, gene activation, and a variety of other biological processes and disease states. The observations of the variety, frequency and co-occurrence of histone modifications in distinct patterns at specific genomic loci have led to the idea that hPTMs can create a molecular barcode, read by effector proteins that translate it into a specific transcriptional state, or process, on the underlying DNA. However, despite the fact that this histone-code hypothesis was proposed more than 10 years ago, the molecular details of its working mechanisms are only partially characterized. In particular, two questions deserve specific investigation: how the different modifications associate and synergize into patterns and how these PTM configurations are read and translated by multi-protein complexes into a specific functional outcome on the genome. Mass spectrometry (MS) has emerged as a versatile tool to investigate chromatin biology, useful for both identifying and validating hPTMs, and to dissect the molecular determinants of histone modification readout systems. We review here the MS techniques and the proteomics methods that have been developed to address these fundamental questions in epigenetics research, emphasizing approaches based on the proteomic dissection of distinct native chromatin regions, with a critical evaluation of their present challenges and future potential. This article is part of a Special Issue entitled: Molecular mechanisms of histone modification function.
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Affiliation(s)
- Monica Soldi
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Michael Bremang
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Tiziana Bonaldi
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139 Milan, Italy.
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7
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Bremang M, Cuomo A, Agresta AM, Stugiewicz M, Spadotto V, Bonaldi T. Mass spectrometry-based identification and characterisation of lysine and arginine methylation in the human proteome. MOLECULAR BIOSYSTEMS 2014; 9:2231-47. [PMID: 23748837 DOI: 10.1039/c3mb00009e] [Citation(s) in RCA: 124] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Protein methylation is a post-translational modification (PTM) by which a variable number of methyl groups are transferred to lysine and arginine residues within proteins. Despite increased interest in this modification due to its reversible nature and its emerging role in a diverse set of biological pathways beyond chromatin, global identification of protein methylation has remained an unachieved goal. To characterise sites of lysine and arginine methylation beyond histones, we employed an approach that combines heavy methyl stable isotope labelling by amino acids in cell culture (hmSILAC) with high-resolution mass spectrometry-based proteomics. Through a broad evaluation of immuno-affinity enrichment and the application of two classical protein separation techniques prior to mass spectrometry, to nucleosolic and cytosolic fractions separately, we identified a total of 501 different methylation types, on 397 distinct lysine and arginine sites, present on 139 unique proteins. Our results considerably extend the number of known in vivo methylation sites and indicate their significant presence on several protein complexes involved at all stages of gene expression, from chromatin remodelling and transcription to splicing and translation. In addition, we describe the potential of the hmSILAC approach for accurate relative quantification of methylation levels between distinct functional states.
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Affiliation(s)
- Michael Bremang
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139 Milan, Italy
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8
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Kussmann M, Morine MJ, Hager J, Sonderegger B, Kaput J. Perspective: a systems approach to diabetes research. Front Genet 2013; 4:205. [PMID: 24187547 PMCID: PMC3807566 DOI: 10.3389/fgene.2013.00205] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Accepted: 09/24/2013] [Indexed: 12/17/2022] Open
Abstract
We review here the status of human type 2 diabetes studies from a genetic, epidemiological, and clinical (intervention) perspective. Most studies limit analyses to one or a few omic technologies providing data of components of physiological processes. Since all chronic diseases are multifactorial and arise from complex interactions between genetic makeup and environment, type 2 diabetes mellitus (T2DM) is a collection of sub-phenotypes resulting in high fasting glucose. The underlying gene–environment interactions that produce these classes of T2DM are imperfectly characterized. Based on assessments of the complexity of T2DM, we propose a systems biology approach to advance the understanding of origin, onset, development, prevention, and treatment of this complex disease. This systems-based strategy is based on new study design principles and the integrated application of omics technologies: we pursue longitudinal studies in which each subject is analyzed at both homeostasis and after (healthy and safe) challenges. Each enrolled subject functions thereby as their own case and control and this design avoids assigning the subjects a priori to case and control groups based on limited phenotyping. Analyses at different time points along this longitudinal investigation are performed with a comprehensive set of omics platforms. These data sets are generated in a biological context, rather than biochemical compound class-driven manner, which we term “systems omics.”
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Affiliation(s)
- Martin Kussmann
- Nestlé Institute of Health Sciences SA Lausanne, Switzerland ; Faculty of Life Sciences, Ecole Polytechnique Fédérale Lausanne, Switzerland ; Faculty of Science, Aarhus University Aarhus, Denmark
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9
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Jung HR, Sidoli S, Haldbo S, Sprenger RR, Schwämmle V, Pasini D, Helin K, Jensen ON. Precision Mapping of Coexisting Modifications in Histone H3 Tails from Embryonic Stem Cells by ETD-MS/MS. Anal Chem 2013; 85:8232-9. [DOI: 10.1021/ac401299w] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Hye Ryung Jung
- Centre for Epigenetics, Department
of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Simone Sidoli
- Centre for Epigenetics, Department
of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Simon Haldbo
- Centre for Epigenetics, Department
of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Richard R. Sprenger
- Centre for Epigenetics, Department
of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Veit Schwämmle
- Centre for Epigenetics, Department
of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Diego Pasini
- Centre for Epigenetics, Biotech
Research and Innovation Centre, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen, Denmark
| | - Kristian Helin
- Centre for Epigenetics, Biotech
Research and Innovation Centre, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen, Denmark
- The Danish Stem Cell Center, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen
N, Denmark
| | - Ole N. Jensen
- Centre for Epigenetics, Department
of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
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10
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Mass spectrometry-based proteomics for the analysis of chromatin structure and dynamics. Int J Mol Sci 2013; 14:5402-31. [PMID: 23466885 PMCID: PMC3634404 DOI: 10.3390/ijms14035402] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Revised: 01/24/2013] [Accepted: 02/20/2013] [Indexed: 12/22/2022] Open
Abstract
Chromatin is a highly structured nucleoprotein complex made of histone proteins and DNA that controls nearly all DNA-dependent processes. Chromatin plasticity is regulated by different associated proteins, post-translational modifications on histones (hPTMs) and DNA methylation, which act in a concerted manner to enforce a specific "chromatin landscape", with a regulatory effect on gene expression. Mass Spectrometry (MS) has emerged as a powerful analytical strategy to detect histone PTMs, revealing interplays between neighbouring PTMs and enabling screens for their readers in a comprehensive and quantitative fashion. Here we provide an overview of the recent achievements of state-of-the-art mass spectrometry-based proteomics for the detailed qualitative and quantitative characterization of histone post-translational modifications, histone variants, and global interactomes at specific chromatin regions. This synopsis emphasizes how the advances in high resolution MS, from "Bottom Up" to "Top Down" analysis, together with the uptake of quantitative proteomics methods by chromatin biologists, have made MS a well-established method in the epigenetics field, enabling the acquisition of original information, highly complementary to that offered by more conventional, antibody-based, assays.
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11
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Lothrop AP, Torres MP, Fuchs SM. Deciphering post-translational modification codes. FEBS Lett 2013; 587:1247-57. [PMID: 23402885 DOI: 10.1016/j.febslet.2013.01.047] [Citation(s) in RCA: 125] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2012] [Revised: 01/20/2013] [Accepted: 01/23/2013] [Indexed: 12/30/2022]
Abstract
Post-translational modifications (PTMs) occur on nearly all proteins. Many domains within proteins are modified on multiple amino acid sidechains by diverse enzymes to create a myriad of possible protein species. How these combinations of PTMs lead to distinct biological outcomes is only beginning to be understood. This manuscript highlights several examples of combinatorial PTMs in proteins, and describes recent technological developments, which are driving our ability to understand how PTM patterns may "code" for biological outcomes.
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Affiliation(s)
- Adam P Lothrop
- Department of Biology, Tufts University, 200 Boston Ave. Suite 4700, Medford, MA 02155, USA
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12
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Sidoli S, Cheng L, Jensen ON. Proteomics in chromatin biology and epigenetics: Elucidation of post-translational modifications of histone proteins by mass spectrometry. J Proteomics 2012; 75:3419-33. [PMID: 22234360 DOI: 10.1016/j.jprot.2011.12.029] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 12/18/2011] [Accepted: 12/20/2011] [Indexed: 12/11/2022]
Affiliation(s)
- Simone Sidoli
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
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13
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Britton LMP, Gonzales-Cope M, Zee BM, Garcia BA. Breaking the histone code with quantitative mass spectrometry. Expert Rev Proteomics 2012; 8:631-43. [PMID: 21999833 DOI: 10.1586/epr.11.47] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Histone post-translational modifications (PTMs) comprise one of the most intricate nuclear signaling networks that govern gene expression in a long-term and dynamic fashion. These PTMs are considered to be 'epigenetic' or heritable from one cell generation to the next and help establish genomic expression patterns. While much of the analyses of histones have historically been performed using site-specific antibodies, these methods are replete with technical obstacles (i.e., cross-reactivity and epitope occlusion). Mass spectrometry-based proteomics has begun to play a significant role in the interrogation of histone PTMs, revealing many new aspects of these modifications that cannot be easily determined with standard biological approaches. Here, we review the accomplishments of mass spectrometry in the histone field, and outline the future roadblocks that must be overcome for mass spectrometry-based proteomics to become the method of choice for chromatin biologists.
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Affiliation(s)
- Laura-Mae P Britton
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
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14
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Lopes LV, Kussmann M. Proteomics at the interface of psychology, gut physiology and dysfunction: an underexploited approach that deserves expansion. Expert Rev Proteomics 2012; 8:605-14. [PMID: 21999831 DOI: 10.1586/epr.11.50] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Gut functions such as digestion and absorption are essential to life and the emerging insights into the gut-brain axis - that is, the cross talk between the enteric and CNS - point towards critical links between (eating) behavior, psychology, whole body and gut physiology, and digestive and overall health. While proteomics is ideally positioned to shed more light on these interactions, be it applied to the periphery (e.g., blood) or the locus of action (i.e., the gut), it is to date largely underexploited, mainly because of challenging sampling and tissue complexity. In view of the contrast between potential and current delivery of proteomics in the context of intestinal health, this article briefs the reader on the state-of-the-art of molecular intestinal research, reviews current proteomic studies (explicitly focusing on the most recent ones that target inflammatory bowel disease patient samples) and argues for an expansion of this research field.
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Affiliation(s)
- Luísa V Lopes
- Neurosciences Unit, Instituto de Medicina Molecular, Av. Prof. Egas Moniz, 1640-028 Lisboa, Portugal.
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15
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Guillemette B, Drogaris P, Lin HHS, Armstrong H, Hiragami-Hamada K, Imhof A, Bonneil É, Thibault P, Verreault A, Festenstein RJ. H3 lysine 4 is acetylated at active gene promoters and is regulated by H3 lysine 4 methylation. PLoS Genet 2011; 7:e1001354. [PMID: 21483810 PMCID: PMC3069113 DOI: 10.1371/journal.pgen.1001354] [Citation(s) in RCA: 148] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2010] [Accepted: 02/25/2011] [Indexed: 11/18/2022] Open
Abstract
Methylation of histone H3 lysine 4 (H3K4me) is an evolutionarily conserved modification whose role in the regulation of gene expression has been extensively studied. In contrast, the function of H3K4 acetylation (H3K4ac) has received little attention because of a lack of tools to separate its function from that of H3K4me. Here we show that, in addition to being methylated, H3K4 is also acetylated in budding yeast. Genetic studies reveal that the histone acetyltransferases (HATs) Gcn5 and Rtt109 contribute to H3K4 acetylation in vivo. Whilst removal of H3K4ac from euchromatin mainly requires the histone deacetylase (HDAC) Hst1, Sir2 is needed for H3K4 deacetylation in heterochomatin. Using genome-wide chromatin immunoprecipitation (ChIP), we show that H3K4ac is enriched at promoters of actively transcribed genes and located just upstream of H3K4 tri-methylation (H3K4me3), a pattern that has been conserved in human cells. We find that the Set1-containing complex (COMPASS), which promotes H3K4me2 and -me3, also serves to limit the abundance of H3K4ac at gene promoters. In addition, we identify a group of genes that have high levels of H3K4ac in their promoters and are inadequately expressed in H3-K4R, but not in set1Δ mutant strains, suggesting that H3K4ac plays a positive role in transcription. Our results reveal a novel regulatory feature of promoter-proximal chromatin, involving mutually exclusive histone modifications of the same histone residue (H3K4ac and H3K4me). In the nucleus of mammals and yeast, DNA is packaged by forming complexes with histone proteins in a structure called the nucleosome, the basic building block of chromatin. The tails of the histones protrude from the nucleosome and can be marked on many amino acid residues by chemical modifications such as methylation and acetylation. A highly studied modification, which is robustly associated with active gene promoters, is histone H3 lysine 4 methylation. We describe here a novel modification, histone H3 lysine 4 acetylation (H3K4ac), which can occur on the same lysine of the histone H3 tail (but not at the same time as methylation). We have identified the enzymes responsible for depositing and removing this mark and mapped its distribution throughout the yeast genome. We found that H3K4ac is present on active genes and is important for the full expression of a subset of them. Strikingly, H3K4 methylation was found in the same promoters as H3K4ac and contributes to regulate the abundance and localisation of H3K4ac. This example of cross-talk between two different modifications of the same residue has fundamental implications for understanding how genes are activated and how their packaging in the nucleus controls this process.
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Affiliation(s)
- Benoit Guillemette
- Department of Medicine, Imperial College London, Hammersmith Hospital Campus, London, United Kingdom
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Canada
| | - Paul Drogaris
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Canada
| | - Hsiu-Hsu Sophia Lin
- Department of Medicine, Imperial College London, Hammersmith Hospital Campus, London, United Kingdom
| | - Harry Armstrong
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Canada
| | - Kyoko Hiragami-Hamada
- Laboratory for Chromatin Dynamics, Riken Kobe Institute, Centre for Developmental Biology, Kobe, Hyogo, Japan
| | - Axel Imhof
- Adolf-Butenandt Institute, Ludwig-Maximilians-University Munich (LMU), Center of Integrated Protein Science (CIPS), Munich, Germany
| | - Éric Bonneil
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Canada
| | - Pierre Thibault
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Canada
- Département de Chimie, Université de Montréal, Montreal, Canada
| | - Alain Verreault
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Canada
- Département de Pathologie et Biologie Cellulaire, Université de Montréal, Montreal, Canada
| | - Richard J. Festenstein
- Department of Medicine, Imperial College London, Hammersmith Hospital Campus, London, United Kingdom
- Medical Research Council Clinical Sciences Centre, London, United Kingdom
- * E-mail:
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16
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Jufvas Å, Strålfors P, Vener AV. Histone variants and their post-translational modifications in primary human fat cells. PLoS One 2011; 6:e15960. [PMID: 21249133 PMCID: PMC3017551 DOI: 10.1371/journal.pone.0015960] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Accepted: 12/01/2010] [Indexed: 01/12/2023] Open
Abstract
Epigenetic changes related to human disease cannot be fully addressed by studies of cells from cultures or from other mammals. We isolated human fat cells from subcutaneous abdominal fat tissue of female subjects and extracted histones from either purified nuclei or intact cells. Direct acid extraction of whole adipocytes was more efficient, yielding about 100 µg of protein with histone content of 60%-70% from 10 mL of fat cells. Differential proteolysis of the protein extracts by trypsin or ArgC-protease followed by nanoLC/MS/MS with alternating CID/ETD peptide sequencing identified 19 histone variants. Four variants were found at the protein level for the first time; particularly HIST2H4B was identified besides the only H4 isoform earlier known to be expressed in humans. Three of the found H2A potentially organize small nucleosomes in transcriptionally active chromatin, while two H2AFY variants inactivate X chromosome in female cells. HIST1H2BA and three of the identified H1 variants had earlier been described only as oocyte or testis specific histones. H2AFX and H2AFY revealed differential and variable N-terminal processing. Out of 78 histone modifications by acetylation/trimethylation, methylation, dimethylation, phosphorylation and ubiquitination, identified from six subjects, 68 were found for the first time. Only 23 of these modifications were detected in two or more subjects, while all the others were individual specific. The direct acid extraction of adipocytes allows for personal epigenetic analyses of human fat tissue, for profiling of histone modifications related to obesity, diabetes and metabolic syndrome, as well as for selection of individual medical treatments.
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Affiliation(s)
- Åsa Jufvas
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Peter Strålfors
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Alexander V. Vener
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
- * E-mail:
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17
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Plazas-Mayorca MD, Vrana KE. Proteomic investigation of epigenetics in neuropsychiatric disorders: a missing link between genetics and behavior? J Proteome Res 2010; 10:58-65. [PMID: 20735116 DOI: 10.1021/pr100463y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Neuropsychiatric disorders affect a large segment of the human population and result in large costs to society. The majority of such disorders have unknown underlying causes. Recent evidence suggests an important role for epigenetic regulation in the emergence of neuropsychiatric disease. Epigenetics may provide a link between genetic and environmental factors and behavior. Epigenetic signaling involves changes on the structure of chromatin; such changes are often triggered and maintained by the post-translational modification of chromatin proteins and/or DNA. Recent proteomic technologies have enabled the study of epigenetic mechanisms in a high-throughput manner. This review will provide an overview of the major epigenetic pathways and modern techniques for their study, before focusing on experimental evidence supporting a strong role for epigenetics in selected psychiatric disorders such as depression, schizophrenia, and drug addiction. These results highlight a great need for the inclusion of the proteomic characterization of epigenetic mechanisms in the study of gene/disease associations in psychiatric disorders.
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Affiliation(s)
- Mariana D Plazas-Mayorca
- Department of Pharmacology, Penn State University College of Medicine, Hershey, Pennsylvania, USA
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18
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Mackeen MM, Kramer HB, Chang KH, Coleman ML, Hopkinson RJ, Schofield CJ, Kessler BM. Small-molecule-based inhibition of histone demethylation in cells assessed by quantitative mass spectrometry. J Proteome Res 2010; 9:4082-4092. [PMID: 20583823 PMCID: PMC4681095 DOI: 10.1021/pr100269b] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Post-translational modifications on histones are an important mechanism for the regulation of gene expression and are involved in all aspects of cell growth and differentiation, as well as pathological processes including neurodegeneration, autoimmunity, and cancer. A major challenge within the chromatin field is to develop methods for the quantitative analysis of histone modifications. Here we report a mass spectrometry (MS) approach based on ultraperformance liquid chromatography high/low collision switching (UPLC-MS(E)) to monitor histone modifications in cells. This approach is exemplified by the analysis of trimethylated lysine-9 levels in histone H3, following a simple chemical derivatization procedure with d(6)-acetic anhydride. This method was used to study the inhibition of histone demethylases with pyridine-2,4-dicarboxylic acid (PDCA) derivatives in cells. Our results show that the PDCA-dimethyl ester inhibits JMJD2A catalyzed demethylation of lysine-9 on histone H3 in human HEK 293T cells. Demethylase inhibition, as observed by MS analyses, was supported by immunoblotting with modification-specific antibodies. The results demonstrate that PDCA derived small molecules are cell permeable demethylase inhibitors and reveal that quantitative MS is a useful tool for measuring post-translational histone modifications in cells.
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Affiliation(s)
- Mukram M. Mackeen
- Chemistry Research Laboratory and the Oxford Centre for Integrative Systems Biology, University of Oxford, 12 Mansfield Road, OX1 3TA, Oxford, U.K
| | - Holger B. Kramer
- Henry Wellcome Building for Molecular Physiology, Department of Clinical Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, U.K
| | - Kai-Hsuan Chang
- Chemistry Research Laboratory and the Oxford Centre for Integrative Systems Biology, University of Oxford, 12 Mansfield Road, OX1 3TA, Oxford, U.K
| | - Matthew L. Coleman
- Henry Wellcome Building for Molecular Physiology, Department of Clinical Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, U.K
| | - Richard J. Hopkinson
- Chemistry Research Laboratory and the Oxford Centre for Integrative Systems Biology, University of Oxford, 12 Mansfield Road, OX1 3TA, Oxford, U.K
| | - Christopher J. Schofield
- Chemistry Research Laboratory and the Oxford Centre for Integrative Systems Biology, University of Oxford, 12 Mansfield Road, OX1 3TA, Oxford, U.K
| | - Benedikt M. Kessler
- Henry Wellcome Building for Molecular Physiology, Department of Clinical Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, U.K
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19
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Ytterberg AJ, Jensen ON. Modification-specific proteomics in plant biology. J Proteomics 2010; 73:2249-66. [PMID: 20541636 DOI: 10.1016/j.jprot.2010.06.002] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2010] [Revised: 05/18/2010] [Accepted: 06/01/2010] [Indexed: 10/19/2022]
Abstract
Post-translational modifications (PTMs) are involved in the regulation of a wide range of biological processes, and affect e.g. protein structure, activity and stability. Several hundred PTMs have been described in the literature, but relatively few have been studied using mass spectrometry and proteomics. In general, methods for PTM characterization are developed to study yeast and mammalian biology and later adopted to investigate plants. Our point of view is that it is advantageous to enrich for PTMs on the peptide level as part of a quantitative proteomics strategy to not only identify the PTM, but also to determine the functional relevance in the context of regulation, response to abiotic stress etc. Protein phosphorylation is the only PTM that has been studied extensively at the proteome wide level in plants using mass spectrometry based methods. We review phosphoproteomics studies in plants and discuss the redox mediated PTMs (S-nitrosylation, tyrosine nitration and S-glutathionylation), ubiquitylation, SUMOylation, and glycosylation, including GPI anchors, and the quantitative proteomics methods that are used to study these modification in plants. Where appropriate we contrast the methods to those used for mammalian PTM characterization.
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Affiliation(s)
- A Jimmy Ytterberg
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense M, Denmark.
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20
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Plazas-Mayorca MD, Zee BM, Young NL, Fingerman IM, LeRoy G, Briggs SD, Garcia BA. One-pot shotgun quantitative mass spectrometry characterization of histones. J Proteome Res 2010; 8:5367-74. [PMID: 19764812 DOI: 10.1021/pr900777e] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Despite increasing applications of mass spectrometry (MS) to characterize post-translational modifications (PTMs) on histone proteins, most existing protocols are not properly suited to robustly measure them in a high-throughput quantitative manner. In this work, we expand on current protocols and describe improved methods for quantitative Bottom Up characterization of histones and their PTMs with comparable sensitivity but much higher throughput than standard MS approaches. This is accomplished by first bypassing off-line fractionation of histone proteins and working directly with total histones from a typical nuclei acid extraction. Next, using a chemical derivatization procedure that is combined with stable-isotope labeling in a two-step process, we can quantitatively compare samples using nanoLC-MS/MS. We show that our method can successfully detect 17 combined H2A/H2B variants and over 25 combined histone H3 and H4 PTMs in a single MS experiment. We test our method by quantifying differentially expressed histone PTMs from wild-type yeast and a methyltransferase knockout strain. This improved methodology establishes that time and sample consuming off-line HPLC or SDS-PAGE purification of individual histone variants prior to MS interrogation as commonly performed is not strictly required. Our protocol significantly streamlines the analysis of histone PTMs and will allow for studies of differentially expressed PTMs between multiple samples during biologically relevant processes in a rapid and quantitative fashion.
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21
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Jung HR, Pasini D, Helin K, Jensen ON. Quantitative mass spectrometry of histones H3.2 and H3.3 in Suz12-deficient mouse embryonic stem cells reveals distinct, dynamic post-translational modifications at Lys-27 and Lys-36. Mol Cell Proteomics 2010; 9:838-50. [PMID: 20150217 DOI: 10.1074/mcp.m900489-mcp200] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
SUZ12 is a core component of the polycomb repressive complex 2 (PRC2) and is required for the differentiation of mouse embryonic stem cells (ESCs). PRC2 is associated with transcriptional repression via methylation of H3 Lys-27. We applied quantitative mass spectrometry to investigate the effects of Suz12 deficiency on H3.2 and H3.3 from mouse ESCs. Using high mass accuracy MS combined with CID or electron transfer dissociation (ETD) tandem mass spectrometry, we identified a total of 81 unique modified peptides from H3.2 and H3.3 and assigned 46 modifications at 22 different positions, including distinct coexisting modifications. In certain cases, high mass accuracy LTQ-Orbitrap MS/MS allowed precise localization of near isobaric coexisting PTMs such as trimethylation and acetylation within individual peptides. ETD MS/MS facilitated sequencing and annotation of phosphorylated histone peptides. The combined use of ETD and CID MS/MS increased the total number of identified modified peptides. Comparative quantitative analysis of histones from wild type and Suz12-deficient ESCs using stable isotope labeling with amino acids in cell culture and LC-MS/MS revealed a dramatic reduction of H3K27me2 and H3K27me3 and an increase of H3K27ac, thereby uncovering an antagonistic methyl/acetyl switch at H3K27. The reduction in H3K27 methylation and increase in H3K27 acetylation was accompanied by H3K36 acetylation and methylation. Estimation of the global isoform percentage of unmodified and modified histone peptides (amino acids 27-40) showed the relative distribution of distinct coexisting histone marks. Our study revealed limitations of antibody-based Western blotting methods for detection of coexisting protein modifications and demonstrated the utility of quantitative tandem mass spectrometry for detailed analysis of the dynamics of coexisting post-translational modifications in proteins.
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Affiliation(s)
- Hye Ryung Jung
- Centre for Epigenetics, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
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22
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Kessler BM. Challenges ahead for mass spectrometry and proteomics applications in epigenetics. Epigenomics 2010; 2:163-7. [DOI: 10.2217/epi.09.37] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Inheritance of biological information to future generations depends on the replication of DNA and the Mendelian principle of distribution of genes. In addition, external and environmental factors can influence traits that can be propagated to offspring, but the molecular details of this are only beginning to be understood. The discoveries of DNA methylation and post-translational modifications on chromatin and histones provided entry points for regulating gene expression, an area now defined as epigenetics and epigenomics. Mass spectrometry turned out to be instrumental in uncovering molecular details involved in these processes. The central role of histone post-translational modifications in epigenetics related biological processes has revitalized mass spectrometry based investigations. In this special report, current approaches and future challenges that lay ahead due to the enormous complexity are discussed.
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Affiliation(s)
- Benedikt M Kessler
- Henry Wellcome Building for Molecular Physiology, Central Proteomics Facility, Department of Clinical Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7BN, UK
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23
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Trelle MB, Salcedo-Amaya AM, Cohen AM, Stunnenberg HG, Jensen ON. Global histone analysis by mass spectrometry reveals a high content of acetylated lysine residues in the malaria parasite Plasmodium falciparum. J Proteome Res 2009; 8:3439-50. [PMID: 19351122 DOI: 10.1021/pr9000898] [Citation(s) in RCA: 113] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Post-translational modifications (PTMs) of histone tails play a key role in epigenetic regulation of gene expression in a range of organisms from yeast to human; however, little is known about histone proteins from the parasite that causes malaria in humans, Plasmodium falciparum. We characterized P. falciparum histone PTMs using advanced mass spectrometry driven proteomics. Acid-extracted proteins were resolved in SDS-PAGE, in-gel trypsin digested, and analyzed by reversed-phase LC-MS/MS. Through the combination of Q-TOF and LTQ-FT mass spectrometry we obtained high mass accuracy of both precursor and fragment ions, which is a prerequisite for high-confidence identifications of multisite peptide modifications. We utilize MS/MS fragment marker ions to validate the identification of histone modifications and report the m/z 143 ion as a novel MS/MS marker ion for monomethylated lysine. We identified all known P. falciparum histones and mapped 44 different modifications, providing a comprehensive view of epigenetic marks in the parasite. Interestingly, the parasite exhibits a histone modification pattern that is distinct from its human host. A general preponderance for modifications associated with a transcriptionally permissive state was observed. Additionally, a novel differentiation in the modification pattern of the two histone H2B variants (H2B and H2Bv) was observed, suggesting divergent functions of the two H2B variants in the parasite. Taken together, our results provide a first comprehensive map of histone modifications in P. falciparum and highlight the utility of tandem MS for detailed analysis of peptides containing multiple PTMs.
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Affiliation(s)
- Morten B Trelle
- Department of Biochemistry and Molecular Biology, Protein Research Group, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
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24
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Abstract
Posttranslational modifications (PTMs) of proteins perform crucial roles in regulating the biology of the cell. PTMs are enzymatic, covalent chemical modifications of proteins that typically occur after the translation of mRNAs. These modifications are relevant because they can potentially change a protein's physical or chemical properties, activity, localization, or stability. Some PTMs can be added and removed dynamically as a mechanism for reversibly controlling protein function and cell signaling. Extensive investigations have aimed to identify PTMs and characterize their biological functions. This chapter will discuss the existing and emerging techniques in the field of mass spectrometry and proteomics that are available to identify and quantify PTMs. We will focus on the most frequently studied modifications. In addition, we will include an overview of the available tools and technologies in tandem mass spectrometry instrumentation that affect the ability to identify specific PTMs.
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Affiliation(s)
- Adam R Farley
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
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25
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Abstract
Diet and genomes interact. Nutrition has the most important life-long environmental impact on human health. While nutrigenetics addresses how an individual’s genetic makeup predisposes for dietary susceptibility, nutrigenomics asks how nutrition influences the expression of the genome. Nutrigenomics builds on the three omics disciplines transcriptomics, proteomics and metabolomics. They are a prerequisite for nutritional systems biology, the understanding of the interaction between food components and diet with cells, organs and the whole body. Personalized nutrition is a conceptual analog to personalized medicine. While there are food products available that address requirements or preferences of specific consumer groups, these products are based on empirical consumer science rather than on nutrigenomics and nutrigenetics. The latter two build the science foundation for understanding human variability in preferences, requirements and responses to diet, and may become the future tools for consumer assessment motivated by personalized nutritional counseling for health maintenance and disease prevention.
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Affiliation(s)
- Martin Kussmann
- Nestlé Research Center, BioAnalytical Science Department, Vers-chez-les-Blanc, Lausanne, Switzerland
| | - Laurent B Fay
- Nestlé Research Center, BioAnalytical Science Department, Vers-chez-les-Blanc, Lausanne, Switzerland
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26
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Van Hoof D, Heck AJR, Krijgsveld J, Mummery CL. Proteomics and human embryonic stem cells. Stem Cell Res 2008; 1:169-82. [PMID: 19383398 DOI: 10.1016/j.scr.2008.05.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2008] [Revised: 05/07/2008] [Accepted: 05/12/2008] [Indexed: 01/08/2023] Open
Abstract
The derivation of human embryonic stem cells (hESCs) brought cell therapy-based regenerative medicine significantly closer to clinical application. However, expansion of undifferentiated cells and their directed differentiation in vitro have proven difficult to control. This is mainly because of a lack of knowledge of the intracellular signaling events that direct these complex processes. Additionally, extracellular factors, either secreted by feeder cells that support self-renewal and maintain pluripotency or present in serum supplementing proprietary culture media, that influence hESC behavior are largely unknown. Xeno-free media that effectively support long-term hESC self-renewal and differentiation to specific types of specialized cells are only slowly becoming available. Microarray-based transcriptome analyses have produced valuable gene expression profiles of hESCs and indicated changes in transcription that occur during differentiation. However, proteins are the actual effectors of these events and changes in their levels do not always match changes in their corresponding mRNA. Furthermore, information on posttranslational modifications that influence the activity of pivotal proteins is still largely missing. Over the years, mass spectrometry has experienced major breakthroughs in high-throughput identification of proteins and posttranslational modifications in cells under different conditions. Mass spectrometry-based proteomic techniques are being applied with increasing frequency to analyze hESCs, as well as media conditioned by feeder cells, and have generated proteome profiles that not only support, but also complement, existing microarray data. In this review, the various proteomic studies on hESCs and feeder cells are discussed. In a meta-analysis, comparison of published data sets distinguished 32 intracellular proteins and 16 plasma membrane proteins that are present in multiple hESC lines but not in differentiated cells, which were therefore likely to include proteins important for hESCs. In addition, 13 and 24 proteins, respectively, were commonly found in different feeder cell lines of mouse and human origin, some of which may be extracellular signaling molecules that play a key role in the undifferentiated propagation of hESCs. These findings underscore the power of mass spectrometry-based techniques to identify novel proteins associated with hESCs by studying these cells in an unbiased, discovery-oriented manner on a proteome-wide scale.
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Affiliation(s)
- Dennis Van Hoof
- Developmental Biology and Stem Cell Research, Hubrecht Institute, Utrecht, The Netherlands
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27
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Trelle MB, Jensen ON. Utility of immonium ions for assignment of epsilon-N-acetyllysine-containing peptides by tandem mass spectrometry. Anal Chem 2008; 80:3422-30. [PMID: 18338905 DOI: 10.1021/ac800005n] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Tandem mass spectrometry (MS/MS) is a powerful tool for characterization of post-translationally modified proteins, including epsilon-N-acetyllysine-containing species. Previous reports indicate that epsilon-N-acetyllysine immonium ions are useful marker ions for peptides containing epsilon-N-acetyllysine, but the specificity and sensitivity of these ions for assignment of lysine acetylation by MS/MS have not been studied in detail. We investigated MS/MS data sets of 172 epsilon-N-acetyllysine tryptic peptides and 268 nonacetylated tryptic peptides to establish the utility and reliability of epsilon-N-acetyllysine immonium ions for identification and validation of acetylated peptides. Our analysis shows that the immonium ion at m/z 143 lacks specificity for lysine-acetylated peptides, whereas the derivative at m/z 126 is highly specific (98.1%). We also studied the positional effect of the epsilon-N-acetyllysine on the intensity of observed acetyllysine immonium ions. We observed an increase in acetyllysine immonium ion intensities when the acetylated lysine was N-terminally positioned in the peptide as compared to internal positions. Based on these observations we propose a validation scheme for unambiguous assignment of acetyllysine-containing peptides by MS/MS. Our analysis of epsilon-N-acetyllysine immonium ions provide a framework for investigation of MS/MS marker ion specificity and sensitivity that can be applied in studies of other types of post-translational modifications.
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Affiliation(s)
- Morten B Trelle
- Department of Biochemistry and Molecular Biology and Centre for Epigenetics, University of Southern Denmark, DK-5230 Odense M, Denmark
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28
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Abstract
A significant portion of ongoing epigenetic research involves the investigation of DNA methylation and chromatin modification patterns seen throughout many biological processes. Over the last few years, epigenetic research has undergone a gradual shift and recent studies have been directed toward a genome-wide assessment. DNA methylation and chromatin modifications are essential components of the regulation of gene activity. DNA methylation effectively down-regulates gene activity by addition of a methyl group to the five-carbon of a cytosine base. Less specifically, modification of the chromatin structure can be carried out by multiple mechanisms leading to either the upregulation or down-regulation of the associated gene. Of the many assays used to assess the effects of epigenetic modifications, chromatin immunoprecipitation (ChIP), which serves to monitor changes in chromatin structure, and bisulfite modification, which tracks changes in DNA methylation, are the two most commonly used techniques.
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