1
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Cirillo L, Young R, Veerapathiran S, Roberti A, Martin M, Abubacar A, Perosa C, Coates C, Muhammad R, Roumeliotis TI, Choudhary JS, Alfieri C, Pines J. Spatial control of the APC/C ensures the rapid degradation of cyclin B1. EMBO J 2024:10.1038/s44318-024-00194-2. [PMID: 39143240 DOI: 10.1038/s44318-024-00194-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 07/22/2024] [Accepted: 07/26/2024] [Indexed: 08/16/2024] Open
Abstract
The proper control of mitosis depends on the ubiquitin-mediated degradation of the right mitotic regulator at the right time. This is effected by the Anaphase Promoting Complex/Cyclosome (APC/C) ubiquitin ligase that is regulated by the Spindle Assembly Checkpoint (SAC). The SAC prevents the APC/C from recognising Cyclin B1, the essential anaphase and cytokinesis inhibitor, until all chromosomes are attached to the spindle. Once chromosomes are attached, Cyclin B1 is rapidly degraded to enable chromosome segregation and cytokinesis. We have a good understanding of how the SAC inhibits the APC/C, but relatively little is known about how the APC/C recognises Cyclin B1 as soon as the SAC is turned off. Here, by combining live-cell imaging, in vitro reconstitution biochemistry, and structural analysis by cryo-electron microscopy, we provide evidence that the rapid recognition of Cyclin B1 in metaphase requires spatial regulation of the APC/C. Using fluorescence cross-correlation spectroscopy, we find that Cyclin B1 and the APC/C primarily interact at the mitotic apparatus. We show that this is because Cyclin B1, like the APC/C, binds to nucleosomes, and identify an 'arginine-anchor' in the N-terminus as necessary and sufficient for binding to the nucleosome. Mutating the arginine anchor on Cyclin B1 reduces its interaction with the APC/C and delays its degradation: cells with the mutant, non-nucleosome-binding Cyclin B1 become aneuploid, demonstrating the physiological relevance of our findings. Together, our data demonstrate that mitotic chromosomes promote the efficient interaction between Cyclin B1 and the APC/C to ensure the timely degradation of Cyclin B1 and genomic stability.
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Affiliation(s)
- Luca Cirillo
- The Institute of Cancer Research Chester Beatty Laboratories, 237 Fulham Road, London, SW3 6JB, UK
| | - Rose Young
- The Institute of Cancer Research Chester Beatty Laboratories, 237 Fulham Road, London, SW3 6JB, UK
| | | | - Annalisa Roberti
- The Institute of Cancer Research Chester Beatty Laboratories, 237 Fulham Road, London, SW3 6JB, UK
| | - Molly Martin
- The Institute of Cancer Research Chester Beatty Laboratories, 237 Fulham Road, London, SW3 6JB, UK
| | - Azzah Abubacar
- The Institute of Cancer Research Chester Beatty Laboratories, 237 Fulham Road, London, SW3 6JB, UK
| | - Camilla Perosa
- The Institute of Cancer Research Chester Beatty Laboratories, 237 Fulham Road, London, SW3 6JB, UK
| | - Catherine Coates
- The Institute of Cancer Research Chester Beatty Laboratories, 237 Fulham Road, London, SW3 6JB, UK
| | - Reyhan Muhammad
- The Institute of Cancer Research Chester Beatty Laboratories, 237 Fulham Road, London, SW3 6JB, UK
| | - Theodoros I Roumeliotis
- The Institute of Cancer Research Chester Beatty Laboratories, 237 Fulham Road, London, SW3 6JB, UK
| | - Jyoti S Choudhary
- The Institute of Cancer Research Chester Beatty Laboratories, 237 Fulham Road, London, SW3 6JB, UK
| | - Claudio Alfieri
- The Institute of Cancer Research Chester Beatty Laboratories, 237 Fulham Road, London, SW3 6JB, UK.
| | - Jonathon Pines
- The Institute of Cancer Research Chester Beatty Laboratories, 237 Fulham Road, London, SW3 6JB, UK.
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2
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Hiort P, Schlaffner CN, Steen JA, Renard BY, Steen H. multiFLEX-LF: A Computational Approach to Quantify the Modification Stoichiometries in Label-Free Proteomics Data Sets. J Proteome Res 2022; 21:899-909. [PMID: 35086334 PMCID: PMC9936407 DOI: 10.1021/acs.jproteome.1c00669] [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] [Indexed: 01/25/2023]
Abstract
In liquid-chromatography-tandem-mass-spectrometry-based proteomics, information about the presence and stoichiometry of protein modifications is not readily available. To overcome this problem, we developed multiFLEX-LF, a computational tool that builds upon FLEXIQuant, which detects modified peptide precursors and quantifies their modification extent by monitoring the differences between observed and expected intensities of the unmodified precursors. multiFLEX-LF relies on robust linear regression to calculate the modification extent of a given precursor relative to a within-study reference. multiFLEX-LF can analyze entire label-free discovery proteomics data sets in a precursor-centric manner without preselecting a protein of interest. To analyze modification dynamics and coregulated modifications, we hierarchically clustered the precursors of all proteins based on their computed relative modification scores. We applied multiFLEX-LF to a data-independent-acquisition-based data set acquired using the anaphase-promoting complex/cyclosome (APC/C) isolated at various time points during mitosis. The clustering of the precursors allows for identifying varying modification dynamics and ordering the modification events. Overall, multiFLEX-LF enables the fast identification of potentially differentially modified peptide precursors and the quantification of their differential modification extent in large data sets using a personal computer. Additionally, multiFLEX-LF can drive the large-scale investigation of the modification dynamics of peptide precursors in time-series and case-control studies. multiFLEX-LF is available at https://gitlab.com/SteenOmicsLab/multiflex-lf.
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Affiliation(s)
- Pauline Hiort
- Department of Pathology, Boston Children's Hospital, Boston, Massachusetts 02115, United States.,Data Analytics and Computational Statistics, Hasso-Plattner-Institute, Faculty of Digital Engineering, University of Potsdam, Potsdam 14482, Germany
| | - Christoph N Schlaffner
- Department of Pathology, Boston Children's Hospital, Boston, Massachusetts 02115, United States.,Data Analytics and Computational Statistics, Hasso-Plattner-Institute, Faculty of Digital Engineering, University of Potsdam, Potsdam 14482, Germany.,F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, Massachusetts 02115, United States.,Department of Neurology, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Judith A Steen
- F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, Massachusetts 02115, United States.,Department of Neurology, Harvard Medical School, Boston, Massachusetts 02115, United States.,Neurobiology Program, Boston Children's Hospital, Boston, Massachusetts 02115, United States
| | - Bernhard Y Renard
- Data Analytics and Computational Statistics, Hasso-Plattner-Institute, Faculty of Digital Engineering, University of Potsdam, Potsdam 14482, Germany
| | - Hanno Steen
- Department of Pathology, Boston Children's Hospital, Boston, Massachusetts 02115, United States.,Neurobiology Program, Boston Children's Hospital, Boston, Massachusetts 02115, United States.,Department of Pathology, Harvard Medical School, Boston, Massachusetts 02115, United States.,Precision Vaccines Program, Boston Children's Hospital, Boston, Massachusetts 02115, United States
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3
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Schlaffner CN, Kahnert K, Muntel J, Chauhan R, Renard BY, Steen JA, Steen H. FLEXIQuant-LF to quantify protein modification extent in label-free proteomics data. eLife 2020; 9:e58783. [PMID: 33284109 PMCID: PMC7721442 DOI: 10.7554/elife.58783] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 11/23/2020] [Indexed: 12/22/2022] Open
Abstract
Improvements in LC-MS/MS methods and technology have enabled the identification of thousands of modified peptides in a single experiment. However, protein regulation by post-translational modifications (PTMs) is not binary, making methods to quantify the modification extent crucial to understanding the role of PTMs. Here, we introduce FLEXIQuant-LF, a software tool for large-scale identification of differentially modified peptides and quantification of their modification extent without knowledge of the types of modifications involved. We developed FLEXIQuant-LF using label-free quantification of unmodified peptides and robust linear regression to quantify the modification extent of peptides. As proof of concept, we applied FLEXIQuant-LF to data-independent-acquisition (DIA) data of the anaphase promoting complex/cyclosome (APC/C) during mitosis. The unbiased FLEXIQuant-LF approach to assess the modification extent in quantitative proteomics data provides a better understanding of the function and regulation of PTMs. The software is available at https://github.com/SteenOmicsLab/FLEXIQuantLF.
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Affiliation(s)
- Christoph N Schlaffner
- F.M. Kirby Neurobiology Center, Boston Children’s HospitalBostonUnited States
- Department of Neurology, Harvard Medical SchoolBostonUnited States
| | - Konstantin Kahnert
- Department of Pathology, Boston Children’s HospitalBostonUnited States
- Bioinformatics Unit (MF1), Robert Koch InstituteBerlinGermany
- Department of Medical Biotechnology, Institute of Biotechnology, Technische Universität BerlinBerlinGermany
| | - Jan Muntel
- Department of Pathology, Boston Children’s HospitalBostonUnited States
- Department of Pathology, Harvard Medical SchoolBostonUnited States
| | - Ruchi Chauhan
- F.M. Kirby Neurobiology Center, Boston Children’s HospitalBostonUnited States
| | - Bernhard Y Renard
- Bioinformatics Unit (MF1), Robert Koch InstituteBerlinGermany
- Data Analytics and Computational Statistics, Hasso-Plattner-Institute, Faculty of Digital Engineering, University of PotsdamPotsdamGermany
| | - Judith A Steen
- F.M. Kirby Neurobiology Center, Boston Children’s HospitalBostonUnited States
- Department of Neurology, Harvard Medical SchoolBostonUnited States
| | - Hanno Steen
- Department of Pathology, Boston Children’s HospitalBostonUnited States
- Department of Pathology, Harvard Medical SchoolBostonUnited States
- Precision Vaccines Program, Boston Children’s HospitalBostonUnited States
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4
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Bansal S, Tiwari S. Mechanisms for the temporal regulation of substrate ubiquitination by the anaphase-promoting complex/cyclosome. Cell Div 2019; 14:14. [PMID: 31889987 PMCID: PMC6927175 DOI: 10.1186/s13008-019-0057-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 12/04/2019] [Indexed: 12/16/2022] Open
Abstract
The anaphase-promoting complex/cyclosome (APC/C) is a multi-subunit, multifunctional ubiquitin ligase that controls the temporal degradation of numerous cell cycle regulatory proteins to direct the unidirectional cell cycle phases. Several different mechanisms contribute to ensure the correct order of substrate modification by the APC/C complex. Recent advances in biochemical, biophysical and structural studies of APC/C have provided a deep mechanistic insight into the working of this complex ubiquitin ligase. This complex displays remarkable conformational flexibility in response to various binding partners and post-translational modifications, which together regulate substrate selection and catalysis of APC/C. Apart from this, various features and modifications of the substrates also influence their recognition and affinity to APC/C complex. Ultimately, temporal degradation of substrates depends on the kind of ubiquitin modification received, the processivity of APC/C, and other extrinsic mechanisms. This review discusses our current understanding of various intrinsic and extrinsic mechanisms responsible for 'substrate ordering' by the APC/C complex.
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Affiliation(s)
- Shivangee Bansal
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067 India
| | - Swati Tiwari
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067 India
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5
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Melloy PG. The anaphase-promoting complex: A key mitotic regulator associated with somatic mutations occurring in cancer. Genes Chromosomes Cancer 2019; 59:189-202. [PMID: 31652364 DOI: 10.1002/gcc.22820] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Revised: 10/18/2019] [Accepted: 10/22/2019] [Indexed: 12/14/2022] Open
Abstract
The anaphase-promoting complex/cyclosome (APC/C) is an E3 ubiquitin ligase that helps control chromosome separation and exit from mitosis in many different kinds of organisms, including yeast, flies, worms, and humans. This review represents a new perspective on the connection between APC/C subunit mutations and cancer. The complex nature of APC/C and limited mutation analysis of its subunits has made it difficult to determine the relationship of each subunit to cancer. In this work, cancer genomic data were examined to identify APC/C subunits with a greater than 5% alteration frequency in 11 representative cancers using the cBioPortal database. Using the Genetic Determinants of Cancer Patient Survival database, APC/C subunits were also studied and found to be significantly associated with poor patient prognosis in several cases. In comparing these two kinds of cancer genomics data to published large-scale genomic analyses looking for cancer driver genes, ANAPC1 and ANAPC3/CDC27 stood out as being represented in all three types of analyses. Seven other subunits were found to be associated both with >5% alteration frequency in certain cancers and being associated with an effect on cancer patient prognosis. The aim of this review is to provide new approaches for investigators conducting in vivo studies of APC/C subunits and cancer progression. In turn, a better understanding of these APC/C subunits and their role in different cancers will help scientists design drugs that are more precisely targeted to certain cancers, using APC/C mutation status as a biomarker.
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Affiliation(s)
- Patricia G Melloy
- Department of Biological and Allied Health Sciences, Fairleigh Dickinson University, Madison, New Jersey
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6
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Abstract
The separation of sister chromatids at anaphase, which is regulated by an E3 ubiquitin ligase called the anaphase-promoting complex/cyclosome (APC/C), is arguably the most important irrevocable event during the cell cycle. The APC/C and cyclin-dependent kinase 1 (Cdk1) are just two of the many significant cell cycle regulators and exert control through ubiquitylation and phosphorylation, respectively. The temporal and spatial regulation of the APC/C is achieved by multiple mechanisms, including phosphorylation, interaction with the structurally related co-activators Cdc20 and Cdh1, loading of distinct E2 ubiquitin-conjugating enzymes, binding with inhibitors and differential affinities for various substrates. Since the discovery of APC/C 25 years ago, intensive studies have uncovered many aspects of APC/C regulation, but we are still far from a full understanding of this important cellular machinery. Recent high-resolution cryogenic electron microscopy analysis and reconstitution of the APC/C have greatly advanced our understanding of molecular mechanisms underpinning the enzymatic properties of APC/C. In this review, we will examine the historical background and current understanding of APC/C regulation.
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Affiliation(s)
- Hiroyuki Yamano
- Cell Cycle Control Group, UCL Cancer Institute, University College London, Paul O’Gorman Building, 72 Huntley Street, London, WC1E 6DD, UK
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7
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Sahana J, Nassef MZ, Wehland M, Kopp S, Krüger M, Corydon TJ, Infanger M, Bauer J, Grimm D. Decreased E-Cadherin in MCF7 Human Breast Cancer Cells Forming Multicellular Spheroids Exposed to Simulated Microgravity. Proteomics 2018; 18:e1800015. [PMID: 29785723 DOI: 10.1002/pmic.201800015] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 04/27/2018] [Indexed: 12/23/2022]
Abstract
MCF7 human breast cancer cells were cultured under normal gravity (1 g) and on a random positioning machine (RPM) preventing sedimentation. After 2 weeks, adherent 1 g-control and adherent RPM cells (AD) as well as multicellular spheroids (MCS) were harvested. AD and MCS had been exposed to the RPM in the same culture flask. In a subsequent proteome analysis, the majority of the proteins detected showed similar label-free quantification (LFQ) scores in each of the respective subpopulations, but in both AD or MCS cultures, proteins were also found whose LFQs deviated at least twofold from their counterparts in the 1 g-control cells. They included the cell junction protein E-cadherin, which was diminished in MCS cells, where proteins of the E-cadherin autodegradation pathway were enhanced and c-Src (proto-oncogene tyrosine-protein kinase c-Src) was detected. Spheroid formation was prevented by inhibition of c-Src but promoted by antibodies blocking E-cadherin activity. An interaction analysis of the detected proteins that are involved in forming and regulating junctions or adhesion complexes and in E-cadherin autodegradation indicated connections between the two protein groups. This suggests that the balance of proteins that up- or downregulate E-cadherin mediates the tendency of MCF7 cells to form MCS during RPM exposure.
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Affiliation(s)
- Jayashree Sahana
- Department of Biomedicine, Aarhus University, 8000 Aarhus C, Denmark
| | - Mohamed Zakaria Nassef
- Clinic for Plastic, Aesthetic and Hand Surgery, Otto-von-Guericke-University Magdeburg, 39120 Magdeburg, Germany
| | - Markus Wehland
- Clinic for Plastic, Aesthetic and Hand Surgery, Otto-von-Guericke-University Magdeburg, 39120 Magdeburg, Germany
| | - Sascha Kopp
- Clinic for Plastic, Aesthetic and Hand Surgery, Otto-von-Guericke-University Magdeburg, 39120 Magdeburg, Germany
| | - Marcus Krüger
- Clinic for Plastic, Aesthetic and Hand Surgery, Otto-von-Guericke-University Magdeburg, 39120 Magdeburg, Germany
| | - Thomas J Corydon
- Department of Biomedicine, Aarhus University, 8000 Aarhus C, Denmark.,Department of Ophthalmology, Aarhus University Hospital, 8000 Aarhus C, Denmark
| | - Manfred Infanger
- Clinic for Plastic, Aesthetic and Hand Surgery, Otto-von-Guericke-University Magdeburg, 39120 Magdeburg, Germany
| | - Johann Bauer
- Max-Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Daniela Grimm
- Department of Biomedicine, Aarhus University, 8000 Aarhus C, Denmark.,Clinic for Plastic, Aesthetic and Hand Surgery, Otto-von-Guericke-University Magdeburg, 39120 Magdeburg, Germany.,Gravitational Biology and Translational Regenerative Medicine, Faculty of Medicine and Mechanical Engineering, Otto-von-Guericke-University Magdeburg, 39120 Magdeburg, Germany
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8
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Grimes M, Hall B, Foltz L, Levy T, Rikova K, Gaiser J, Cook W, Smirnova E, Wheeler T, Clark NR, Lachmann A, Zhang B, Hornbeck P, Ma'ayan A, Comb M. Integration of protein phosphorylation, acetylation, and methylation data sets to outline lung cancer signaling networks. Sci Signal 2018; 11:eaaq1087. [PMID: 29789295 PMCID: PMC6822907 DOI: 10.1126/scisignal.aaq1087] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Protein posttranslational modifications (PTMs) have typically been studied independently, yet many proteins are modified by more than one PTM type, and cell signaling pathways somehow integrate this information. We coupled immunoprecipitation using PTM-specific antibodies with tandem mass tag (TMT) mass spectrometry to simultaneously examine phosphorylation, methylation, and acetylation in 45 lung cancer cell lines compared to normal lung tissue and to cell lines treated with anticancer drugs. This simultaneous, large-scale, integrative analysis of these PTMs using a cluster-filtered network (CFN) approach revealed that cell signaling pathways were outlined by clustering patterns in PTMs. We used the t-distributed stochastic neighbor embedding (t-SNE) method to identify PTM clusters and then integrated each with known protein-protein interactions (PPIs) to elucidate functional cell signaling pathways. The CFN identified known and previously unknown cell signaling pathways in lung cancer cells that were not present in normal lung epithelial tissue. In various proteins modified by more than one type of PTM, the incidence of those PTMs exhibited inverse relationships, suggesting that molecular exclusive "OR" gates determine a large number of signal transduction events. We also showed that the acetyltransferase EP300 appears to be a hub in the network of pathways involving different PTMs. In addition, the data shed light on the mechanism of action of geldanamycin, an HSP90 inhibitor. Together, the findings reveal that cell signaling pathways mediated by acetylation, methylation, and phosphorylation regulate the cytoskeleton, membrane traffic, and RNA binding protein-mediated control of gene expression.
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Affiliation(s)
- Mark Grimes
- Division of Biological Sciences, and Department of Computer Science, Department of Mathematical Sciences, University of Montana, Missoula, MT 59812, USA.
| | | | - Lauren Foltz
- Division of Biological Sciences, and Department of Computer Science, Department of Mathematical Sciences, University of Montana, Missoula, MT 59812, USA
| | - Tyler Levy
- Cell Signaling Technology, Danvers, MA 01923, USA
| | | | - Jeremiah Gaiser
- Division of Biological Sciences, and Department of Computer Science, Department of Mathematical Sciences, University of Montana, Missoula, MT 59812, USA
| | - William Cook
- Division of Biological Sciences, and Department of Computer Science, Department of Mathematical Sciences, University of Montana, Missoula, MT 59812, USA
| | - Ekaterina Smirnova
- Division of Biological Sciences, and Department of Computer Science, Department of Mathematical Sciences, University of Montana, Missoula, MT 59812, USA
| | - Travis Wheeler
- Division of Biological Sciences, and Department of Computer Science, Department of Mathematical Sciences, University of Montana, Missoula, MT 59812, USA
| | - Neil R Clark
- Department of Pharmacological Sciences, Mount Sinai Center for Bioinformatics, BD2K-LINCS (Big Data to Knowledge Library of Integrated Network-based Cellular Signatures) Data Coordination and Integration Center, Icahn School of Medicine, Mount Sinai, New York, NY 10029, USA
| | - Alexander Lachmann
- Department of Pharmacological Sciences, Mount Sinai Center for Bioinformatics, BD2K-LINCS (Big Data to Knowledge Library of Integrated Network-based Cellular Signatures) Data Coordination and Integration Center, Icahn School of Medicine, Mount Sinai, New York, NY 10029, USA
| | - Bin Zhang
- Cell Signaling Technology, Danvers, MA 01923, USA
| | | | - Avi Ma'ayan
- Department of Pharmacological Sciences, Mount Sinai Center for Bioinformatics, BD2K-LINCS (Big Data to Knowledge Library of Integrated Network-based Cellular Signatures) Data Coordination and Integration Center, Icahn School of Medicine, Mount Sinai, New York, NY 10029, USA
| | - Michael Comb
- Cell Signaling Technology, Danvers, MA 01923, USA
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9
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Alfieri C, Zhang S, Barford D. Visualizing the complex functions and mechanisms of the anaphase promoting complex/cyclosome (APC/C). Open Biol 2017; 7:170204. [PMID: 29167309 PMCID: PMC5717348 DOI: 10.1098/rsob.170204] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 10/10/2017] [Indexed: 12/17/2022] Open
Abstract
The anaphase promoting complex or cyclosome (APC/C) is a large multi-subunit E3 ubiquitin ligase that orchestrates cell cycle progression by mediating the degradation of important cell cycle regulators. During the two decades since its discovery, much has been learnt concerning its role in recognizing and ubiquitinating specific proteins in a cell-cycle-dependent manner, the mechanisms governing substrate specificity, the catalytic process of assembling polyubiquitin chains on its target proteins, and its regulation by phosphorylation and the spindle assembly checkpoint. The past few years have witnessed significant progress in understanding the quantitative mechanisms underlying these varied APC/C functions. This review integrates the overall functions and properties of the APC/C with mechanistic insights gained from recent cryo-electron microscopy (cryo-EM) studies of reconstituted human APC/C complexes.
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Affiliation(s)
- Claudio Alfieri
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Suyang Zhang
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - David Barford
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
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10
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Cdc20: At the Crossroads between Chromosome Segregation and Mitotic Exit. Trends Biochem Sci 2017; 42:193-205. [PMID: 28202332 DOI: 10.1016/j.tibs.2016.12.001] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 11/13/2016] [Accepted: 12/06/2016] [Indexed: 11/21/2022]
Abstract
Cell-division cycle protein 20 homologue (Cdc20) has important functions in chromosome segregation and mitotic exit. Cdc20 is the target of the spindle assembly checkpoint (SAC) and a key cofactor of the anaphase-promoting complex or cyclosome (APC/C) E3 ubiquitin ligase, thus regulating APC/C ubiquitin activity on specific substrates for their subsequent degradation by the proteasome. Here we discuss the roles of Cdc20 in SAC signalling and mitotic exit, describe how the integration of traditional approaches with emerging technologies has revealed new details of Cdc20 functions, comment about the potential of Cdc20 as a therapeutic target for the treatment of human malignancies, and discuss recent advances and controversies in the mechanistic understanding of the control of chromosome segregation during cell division.
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11
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Abstract
Understanding cell growth and cell division involves the study of regulatory events that occur in a cell cycle phase-dependent manner. Studies analyzing cell cycle regulatory mechanisms and cell cycle progression invariably require synchronization of cell populations at specific cell cycle stages. Several methods have been established to synchronize cells, including serum deprivation, contact inhibition, centrifugal elutriation, and drug-dependent synchronization. Despite potential adverse cellular consequences of synchronizing cells by pharmacological agents, drug-dependent methods can be advantageous when studying later cell cycle events to ensure specific enrichment at selected mitotic stages. This chapter describes protocols used in our laboratory for isolating mitotic mammalian cells in a large-scale manner. In particular, we discuss the technical aspects of adherent or suspension cell isolation, the methods necessary to enrich cells at different mitotic stages and the optimized culture conditions.
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Affiliation(s)
- Kalyan Dulla
- Department of Cell Biology, Max Planck Institute of Biochemistry, Martinsried, Germany
- Department of Molecular Diagnostics, Philips Corporate Technologies, AE Eindhoven, The Netherlands
| | - Anna Santamaria Margalef
- Cell Cycle and Cancer, Biomedical Research Group in Gynecology, Vall Hebron Research Institute (VHIR) - UAB, Barcelona, 08035, Spain.
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12
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Abstract
The mitotic checkpoint is a specialized signal transduction pathway that contributes to the fidelity of chromosome segregation. The signaling of the checkpoint originates from defective kinetochore-microtubule interactions and leads to formation of the mitotic checkpoint complex (MCC), a highly potent inhibitor of the Anaphase Promoting Complex/Cyclosome (APC/C)—the E3 ubiquitin ligase essential for anaphase onset. Many important questions concerning the MCC and its interaction with APC/C have been intensively investigated and debated in the past 15 years, such as the exact composition of the MCC, how it is assembled during a cell cycle, how it inhibits APC/C, and how the MCC is disassembled to allow APC/C activation. These efforts have culminated in recently reported structure models for human MCC:APC/C supra-complexes at near-atomic resolution that shed light on multiple aspects of the mitotic checkpoint mechanisms. However, confusing statements regarding the MCC are still scattered in the literature, making it difficult for students and scientists alike to obtain a clear picture of MCC composition, structure, function and dynamics. This review will comb through some of the most popular concepts or misconceptions about the MCC, discuss our current understandings, present a synthesized model on regulation of CDC20 ubiquitination, and suggest a few future endeavors and cautions for next phase of MCC research.
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Affiliation(s)
- Song-Tao Liu
- Department of Biological Sciences, University of Toledo, 2801 West Bancroft St., Toledo, OH 43606, USA
| | - Hang Zhang
- Department of Biological Sciences, University of Toledo, 2801 West Bancroft St., Toledo, OH 43606, USA
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13
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Li Q, Chang L, Aibara S, Yang J, Zhang Z, Barford D. WD40 domain of Apc1 is critical for the coactivator-induced allosteric transition that stimulates APC/C catalytic activity. Proc Natl Acad Sci U S A 2016; 113:10547-52. [PMID: 27601667 PMCID: PMC5035875 DOI: 10.1073/pnas.1607147113] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The anaphase-promoting complex/cyclosome (APC/C) is a large multimeric cullin-RING E3 ubiquitin ligase that orchestrates cell-cycle progression by targeting cell-cycle regulatory proteins for destruction via the ubiquitin proteasome system. The APC/C assembly comprises two scaffolding subcomplexes: the platform and the TPR lobe that together coordinate the juxtaposition of the catalytic and substrate-recognition modules. The platform comprises APC/C subunits Apc1, Apc4, Apc5, and Apc15. Although the role of Apc1 as an APC/C scaffolding subunit has been characterized, its specific functions in contributing toward APC/C catalytic activity are not fully understood. Here, we report the crystal structure of the N-terminal domain of human Apc1 (Apc1N) determined at 2.2-Å resolution and provide an atomic-resolution description of the architecture of its WD40 (WD40 repeat) domain (Apc1(WD40)). To understand how Apc1(WD40) contributes to APC/C activity, a mutant form of the APC/C with Apc1(WD40) deleted was generated and evaluated biochemically and structurally. We found that the deletion of Apc1(WD40) abolished the UbcH10-dependent ubiquitination of APC/C substrates without impairing the Ube2S-dependent ubiquitin chain elongation activity. A cryo-EM structure of an APC/C-Cdh1 complex with Apc1(WD40) deleted showed that the mutant APC/C is locked into an inactive conformation in which the UbcH10-binding site of the catalytic module is inaccessible. Additionally, an EM density for Apc15 is not visible. Our data show that Apc1(WD40) is required to mediate the coactivator-induced conformational change of the APC/C that is responsible for stimulating APC/C catalytic activity by promoting UbcH10 binding. In contrast, Ube2S activity toward APC/C substrates is not dependent on the initiation-competent conformation of the APC/C.
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Affiliation(s)
- Qiuhong Li
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom; Section of Structural Biology, Chester Beatty Laboratories, Institute of Cancer Research, London SW3 6JB, United Kingdom
| | - Leifu Chang
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Shintaro Aibara
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Jing Yang
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Ziguo Zhang
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - David Barford
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom;
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14
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Alfieri C, Chang L, Zhang Z, Yang J, Maslen S, Skehel M, Barford D. Molecular basis of APC/C regulation by the spindle assembly checkpoint. Nature 2016; 536:431-436. [PMID: 27509861 PMCID: PMC5019344 DOI: 10.1038/nature19083] [Citation(s) in RCA: 150] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 07/06/2016] [Indexed: 12/12/2022]
Abstract
In the dividing eukaryotic cell, the spindle assembly checkpoint (SAC) ensures that each daughter cell inherits an identical set of chromosomes. The SAC coordinates the correct attachment of sister chromatid kinetochores to the mitotic spindle with activation of the anaphase-promoting complex (APC/C), the E3 ubiquitin ligase responsible for initiating chromosome separation. In response to unattached kinetochores, the SAC generates the mitotic checkpoint complex (MCC), which inhibits the APC/C and delays chromosome segregation. By cryo-electron microscopy, here we determine the near-atomic resolution structure of a human APC/C–MCC complex (APC/C(MCC)). Degron-like sequences of the MCC subunit BubR1 block degron recognition sites on Cdc20, the APC/C coactivator subunit responsible for substrate interactions. BubR1 also obstructs binding of the initiating E2 enzyme UbcH10 to repress APC/C ubiquitination activity. Conformational variability of the complex enables UbcH10 association, and structural analysis shows how the Cdc20 subunit intrinsic to the MCC (Cdc20(MCC)) is ubiquitinated, a process that results in APC/C reactivation when the SAC is silenced.
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Affiliation(s)
- Claudio Alfieri
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Leifu Chang
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Ziguo Zhang
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Jing Yang
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Sarah Maslen
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Mark Skehel
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - David Barford
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
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15
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Zhang S, Chang L, Alfieri C, Zhang Z, Yang J, Maslen S, Skehel M, Barford D. Molecular mechanism of APC/C activation by mitotic phosphorylation. Nature 2016; 533:260-264. [PMID: 27120157 PMCID: PMC4878669 DOI: 10.1038/nature17973] [Citation(s) in RCA: 136] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 04/06/2016] [Indexed: 12/11/2022]
Abstract
In eukaryotes, the anaphase-promoting complex (APC/C, also known as the cyclosome) regulates the ubiquitin-dependent proteolysis of specific cell-cycle proteins to coordinate chromosome segregation in mitosis and entry into the G1 phase. The catalytic activity of the APC/C and its ability to specify the destruction of particular proteins at different phases of the cell cycle are controlled by its interaction with two structurally related coactivator subunits, Cdc20 and Cdh1. Coactivators recognize substrate degrons, and enhance the affinity of the APC/C for its cognate E2 (refs 4-6). During mitosis, cyclin-dependent kinase (Cdk) and polo-like kinase (Plk) control Cdc20- and Cdh1-mediated activation of the APC/C. Hyperphosphorylation of APC/C subunits, notably Apc1 and Apc3, is required for Cdc20 to activate the APC/C, whereas phosphorylation of Cdh1 prevents its association with the APC/C. Since both coactivators associate with the APC/C through their common C-box and Ile-Arg tail motifs, the mechanism underlying this differential regulation is unclear, as is the role of specific APC/C phosphorylation sites. Here, using cryo-electron microscopy and biochemical analysis, we define the molecular basis of how phosphorylation of human APC/C allows for its control by Cdc20. An auto-inhibitory segment of Apc1 acts as a molecular switch that in apo unphosphorylated APC/C interacts with the C-box binding site and obstructs engagement of Cdc20. Phosphorylation of the auto-inhibitory segment displaces it from the C-box-binding site. Efficient phosphorylation of the auto-inhibitory segment, and thus relief of auto-inhibition, requires the recruitment of Cdk-cyclin in complex with a Cdk regulatory subunit (Cks) to a hyperphosphorylated loop of Apc3. We also find that the small-molecule inhibitor, tosyl-l-arginine methyl ester, preferentially suppresses APC/C(Cdc20) rather than APC/C(Cdh1), and interacts with the binding sites of both the C-box and Ile-Arg tail motifs. Our results reveal the mechanism for the regulation of mitotic APC/C by phosphorylation and provide a rationale for the development of selective inhibitors of this state.
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Affiliation(s)
- Suyang Zhang
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Leifu Chang
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Claudio Alfieri
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Ziguo Zhang
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Jing Yang
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Sarah Maslen
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Mark Skehel
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - David Barford
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
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16
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Abstract
Chromosome segregation and mitotic exit are initiated by the 1.2-MDa ubiquitin ligase APC/C (anaphase-promoting complex/cyclosome) and its coactivator CDC20 (cell division cycle 20). To avoid chromosome missegregation, APC/C(CDC20) activation is tightly controlled. CDC20 only associates with APC/C in mitosis when APC/C has become phosphorylated and is further inhibited by a mitotic checkpoint complex until all chromosomes are bioriented on the spindle. APC/C contains 14 different types of subunits, most of which are phosphorylated in mitosis on multiple sites. However, it is unknown which of these phospho-sites enable APC/C(CDC20) activation and by which mechanism. Here we have identified 68 evolutionarily conserved mitotic phospho-sites on human APC/C bound to CDC20 and have used the biGBac technique to generate 47 APC/C mutants in which either all 68 sites or subsets of them were replaced by nonphosphorylatable or phospho-mimicking residues. The characterization of these complexes in substrate ubiquitination and degradation assays indicates that phosphorylation of an N-terminal loop region in APC1 is sufficient for binding and activation of APC/C by CDC20. Deletion of the N-terminal APC1 loop enables APC/C(CDC20) activation in the absence of mitotic phosphorylation or phospho-mimicking mutations. These results indicate that binding of CDC20 to APC/C is normally prevented by an autoinhibitory loop in APC1 and that its mitotic phosphorylation relieves this inhibition. The predicted location of the N-terminal APC1 loop implies that this loop controls interactions between the N-terminal domain of CDC20 and APC1 and APC8. These results reveal how APC/C phosphorylation enables CDC20 to bind and activate the APC/C in mitosis.
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17
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Fujimitsu K, Grimaldi M, Yamano H. Cyclin-dependent kinase 1-dependent activation of APC/C ubiquitin ligase. Science 2016; 352:1121-4. [PMID: 27103671 DOI: 10.1126/science.aad3925] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 04/11/2016] [Indexed: 12/14/2022]
Abstract
Error-free genome duplication and segregation are ensured through the timely activation of ubiquitylation enzymes. The anaphase-promoting complex or cyclosome (APC/C), a multisubunit E3 ubiquitin ligase, is regulated by phosphorylation. However, the mechanism remains elusive. Using systematic reconstitution and analysis of vertebrate APC/Cs under physiological conditions, we show how cyclin-dependent kinase 1 (CDK1) activates the APC/C through coordinated phosphorylation between Apc3 and Apc1. Phosphorylation of the loop domains by CDK1 in complex with p9/Cks2 (a CDK regulatory subunit) controlled loading of coactivator Cdc20 onto APC/C. A phosphomimetic mutation introduced into Apc1 allowed Cdc20 to increase APC/C activity in interphase. These results define a previously unrecognized subunit-subunit communication over a distance and the functional consequences of CDK phosphorylation. Cdc20 is a potential therapeutic target, and our findings may facilitate the development of specific inhibitors.
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Affiliation(s)
- Kazuyuki Fujimitsu
- Cell Cycle Control Group, UCL Cancer Institute, University College London, London WC1E 6DD, UK
| | - Margaret Grimaldi
- Cell Cycle Control Group, UCL Cancer Institute, University College London, London WC1E 6DD, UK
| | - Hiroyuki Yamano
- Cell Cycle Control Group, UCL Cancer Institute, University College London, London WC1E 6DD, UK.
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18
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Cronin NB, Yang J, Zhang Z, Kulkarni K, Chang L, Yamano H, Barford D. Atomic-Resolution Structures of the APC/C Subunits Apc4 and the Apc5 N-Terminal Domain. J Mol Biol 2015; 427:3300-3315. [PMID: 26343760 PMCID: PMC4590430 DOI: 10.1016/j.jmb.2015.08.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 08/19/2015] [Accepted: 08/26/2015] [Indexed: 10/25/2022]
Abstract
Many essential biological processes are mediated by complex molecular machines comprising multiple subunits. Knowledge on the architecture of individual subunits and their positions within the overall multimeric complex is key to understanding the molecular mechanisms of macromolecular assemblies. The anaphase-promoting complex/cyclosome (APC/C) is a large multisubunit complex that regulates cell cycle progression by ubiquitinating cell cycle proteins for proteolysis by the proteasome. The holo-complex is composed of 15 different proteins that assemble to generate a complex of 20 subunits. Here, we describe the crystal structures of Apc4 and the N-terminal domain of Apc5 (Apc5(N)). Apc4 comprises a WD40 domain split by a long α-helical domain, whereas Apc5(N) has an α-helical fold. In a separate study, we had fitted these atomic models to a 3.6-Å-resolution cryo-electron microscopy map of the APC/C. We describe how, in the context of the APC/C, regions of Apc4 disordered in the crystal assume order through contacts to Apc5, whereas Apc5(N) shows small conformational changes relative to its crystal structure. We discuss the complementary approaches of high-resolution electron microscopy and protein crystallography to the structure determination of subunits of multimeric complexes.
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Affiliation(s)
- Nora B Cronin
- Division of Structural Biology, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, United Kingdom
| | - Jing Yang
- Division of Structural Biology, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, United Kingdom; MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Ziguo Zhang
- Division of Structural Biology, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, United Kingdom; MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Kiran Kulkarni
- Division of Structural Biology, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, United Kingdom; Division of Biochemical Sciences, Council of Scientific and Industrial Research National Chemical Laboratory, Pune 411008, India
| | - Leifu Chang
- Division of Structural Biology, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, United Kingdom; MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Hiroyuki Yamano
- Cancer Institute, University College London, Paul O'Gorman Building, 72 Huntley Street, London WC1E 6BT, United Kingdom
| | - David Barford
- Division of Structural Biology, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, United Kingdom; MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom.
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19
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Chang L, Zhang Z, Yang J, McLaughlin SH, Barford D. Atomic structure of the APC/C and its mechanism of protein ubiquitination. Nature 2015; 522:450-454. [PMID: 26083744 PMCID: PMC4608048 DOI: 10.1038/nature14471] [Citation(s) in RCA: 164] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 04/10/2015] [Indexed: 12/12/2022]
Abstract
The anaphase-promoting complex (APC/C) is a multimeric RING E3 ubiquitin ligase that controls chromosome segregation and mitotic exit. Its regulation by coactivator subunits, phosphorylation, the mitotic checkpoint complex and interphase early mitotic inhibitor 1 (Emi1) ensures the correct order and timing of distinct cell-cycle transitions. Here we use cryo-electron microscopy to determine atomic structures of APC/C-coactivator complexes with either Emi1 or a UbcH10-ubiquitin conjugate. These structures define the architecture of all APC/C subunits, the position of the catalytic module and explain how Emi1 mediates inhibition of the two E2s UbcH10 and Ube2S. Definition of Cdh1 interactions with the APC/C indicates how they are antagonized by Cdh1 phosphorylation. The structure of the APC/C with UbcH10-ubiquitin reveals insights into the initiating ubiquitination reaction. Our results provide a quantitative framework for the design of future experiments to investigate APC/C functions in vivo.
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MESH Headings
- Anaphase-Promoting Complex-Cyclosome/chemistry
- Anaphase-Promoting Complex-Cyclosome/metabolism
- Anaphase-Promoting Complex-Cyclosome/ultrastructure
- Antigens, CD
- Apc1 Subunit, Anaphase-Promoting Complex-Cyclosome/chemistry
- Apc1 Subunit, Anaphase-Promoting Complex-Cyclosome/metabolism
- Apc1 Subunit, Anaphase-Promoting Complex-Cyclosome/ultrastructure
- Apc10 Subunit, Anaphase-Promoting Complex-Cyclosome/chemistry
- Apc10 Subunit, Anaphase-Promoting Complex-Cyclosome/metabolism
- Apc10 Subunit, Anaphase-Promoting Complex-Cyclosome/ultrastructure
- Apc11 Subunit, Anaphase-Promoting Complex-Cyclosome/chemistry
- Apc11 Subunit, Anaphase-Promoting Complex-Cyclosome/metabolism
- Apc3 Subunit, Anaphase-Promoting Complex-Cyclosome/chemistry
- Apc3 Subunit, Anaphase-Promoting Complex-Cyclosome/metabolism
- Apc8 Subunit, Anaphase-Promoting Complex-Cyclosome/chemistry
- Apc8 Subunit, Anaphase-Promoting Complex-Cyclosome/metabolism
- Apc8 Subunit, Anaphase-Promoting Complex-Cyclosome/ultrastructure
- Cadherins/chemistry
- Cadherins/metabolism
- Cadherins/ultrastructure
- Catalytic Domain
- Cell Cycle Proteins/chemistry
- Cell Cycle Proteins/metabolism
- Cell Cycle Proteins/ultrastructure
- Cryoelectron Microscopy
- Cytoskeletal Proteins/chemistry
- Cytoskeletal Proteins/metabolism
- F-Box Proteins/chemistry
- F-Box Proteins/metabolism
- F-Box Proteins/ultrastructure
- Humans
- Lysine/metabolism
- Models, Molecular
- Phosphorylation
- Protein Binding
- Protein Subunits/chemistry
- Protein Subunits/metabolism
- Structure-Activity Relationship
- Substrate Specificity
- Ubiquitin/chemistry
- Ubiquitin/metabolism
- Ubiquitin/ultrastructure
- Ubiquitin-Conjugating Enzymes/chemistry
- Ubiquitin-Conjugating Enzymes/metabolism
- Ubiquitin-Conjugating Enzymes/ultrastructure
- Ubiquitination
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Affiliation(s)
- Leifu Chang
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Ziguo Zhang
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Jing Yang
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Stephen H McLaughlin
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - David Barford
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
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20
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Masuda K, Chiyoda T, Sugiyama N, Segura-Cabrera A, Kabe Y, Ueki A, Banno K, Suematsu M, Aoki D, Ishihama Y, Saya H, Kuninaka S. LATS1 and LATS2 phosphorylate CDC26 to modulate assembly of the tetratricopeptide repeat subcomplex of APC/C. PLoS One 2015; 10:e0118662. [PMID: 25723520 PMCID: PMC4344199 DOI: 10.1371/journal.pone.0118662] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 01/09/2015] [Indexed: 12/15/2022] Open
Abstract
In budding yeast, the Mitotic Exit Network (MEN) regulates anaphase promoting complex/cyclosome (APC/C) via the Dbf2-Cdc14 signaling cascade. Dbf2 kinase phosphorylates and activates Cdc14 phosphatase, which removes the inhibitory phosphorylation of the APC/C cofactor Cdh1. Although each component of the MEN was highly conserved during evolution, there is presently no evidence supporting direct phosphorylation of CDC14 by large tumor suppressor kinase 1 (LATS1), the human counterpart of Dbf2; hence, it is unclear how LATS1 regulates APC/C. Here, we demonstrate that LATS1 phosphorylates the Thr7 (T7) residue of the APC/C component CDC26 directly. Nocodazole-induced phosphorylation of T7 was reduced by knockdown of LATS1 and LATS2 in HeLa cells, indicating that both of these kinases contribute to the phosphorylation of CDC26 in vivo. The T7 residue of CDC26 is critical for its interaction with APC6, a tetratricopeptide repeat-containing subunit of APC/C, and mutation of this residue to Asp (T7D) reduced the interaction of CDC26 with APC6. Replacement of endogenous CDC26 in HeLa cells with exogenous phosphor-mimic T7D-mutated CDC26 increased the elution size of APC/C subunits in a gel filtration assay, implying a change in the APC/C assembly upon phosphorylation of CDC26. Furthermore, T7D-mutated CDC26 promoted the ubiquitination of polo-like kinase 1, a well-known substrate of APC/C. Overall, these results suggest that LATS1/2 are novel kinases involved in APC/C phosphorylation and indicate a direct regulatory link between LATS1/2 and APC/C.
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Affiliation(s)
- Kenta Masuda
- Division of Gene Regulation, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo, Japan
- Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo, Japan
| | - Tatsuyuki Chiyoda
- Division of Gene Regulation, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo, Japan
- Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo, Japan
| | - Naoyuki Sugiyama
- Department of Molecular & Cellular BioAnalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Aldo Segura-Cabrera
- Division of Experimental Hematology & Cancer Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - Yasuaki Kabe
- Department of Biochemistry, Keio University School of Medicine, Tokyo, Japan
| | - Arisa Ueki
- Division of Gene Regulation, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo, Japan
- Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo, Japan
| | - Koji Banno
- Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo, Japan
| | - Makoto Suematsu
- Department of Biochemistry, Keio University School of Medicine, Tokyo, Japan
- CREST, Japan Science and Technology Agency, Tokyo, Japan
| | - Daisuke Aoki
- Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo, Japan
| | - Yasushi Ishihama
- Department of Molecular & Cellular BioAnalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Hideyuki Saya
- Division of Gene Regulation, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo, Japan
- * E-mail: (SK); (HS)
| | - Shinji Kuninaka
- Division of Gene Regulation, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo, Japan
- * E-mail: (SK); (HS)
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21
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Prediction of individual response to anticancer therapy: historical and future perspectives. Cell Mol Life Sci 2014; 72:729-57. [PMID: 25387856 PMCID: PMC4309902 DOI: 10.1007/s00018-014-1772-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Revised: 10/23/2014] [Accepted: 10/27/2014] [Indexed: 02/06/2023]
Abstract
Since the introduction of chemotherapy for cancer treatment in the early 20th century considerable efforts have been made to maximize drug efficiency and at the same time minimize side effects. As there is a great interpatient variability in response to chemotherapy, the development of predictive biomarkers is an ambitious aim for the rapidly growing research area of personalized molecular medicine. The individual prediction of response will improve treatment and thus increase survival and life quality of patients. In the past, cell cultures were used as in vitro models to predict in vivo response to chemotherapy. Several in vitro chemosensitivity assays served as tools to measure miscellaneous endpoints such as DNA damage, apoptosis and cytotoxicity or growth inhibition. Twenty years ago, the development of high-throughput technologies, e.g. cDNA microarrays enabled a more detailed analysis of drug responses. Thousands of genes were screened and expression levels were correlated to drug responses. In addition, mutation analysis became more and more important for the prediction of therapeutic success. Today, as research enters the area of -omics technologies, identification of signaling pathways is a tool to understand molecular mechanism underlying drug resistance. Combining new tissue models, e.g. 3D organoid cultures with modern technologies for biomarker discovery will offer new opportunities to identify new drug targets and in parallel predict individual responses to anticancer therapy. In this review, we present different currently used chemosensitivity assays including 2D and 3D cell culture models and several -omics approaches for the discovery of predictive biomarkers. Furthermore, we discuss the potential of these assays and biomarkers to predict the clinical outcome of individual patients and future perspectives.
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22
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Singh SA, Winter D, Kirchner M, Chauhan R, Ahmed S, Ozlu N, Tzur A, Steen JA, Steen H. Co-regulation proteomics reveals substrates and mechanisms of APC/C-dependent degradation. EMBO J 2014; 33:385-99. [PMID: 24510915 DOI: 10.1002/embj.201385876] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Using multiplexed quantitative proteomics, we analyzed cell cycle-dependent changes of the human proteome. We identified >4,400 proteins, each with a six-point abundance profile across the cell cycle. Hypothesizing that proteins with similar abundance profiles are co-regulated, we clustered the proteins with abundance profiles most similar to known Anaphase-Promoting Complex/Cyclosome (APC/C) substrates to identify additional putative APC/C substrates. This protein profile similarity screening (PPSS) analysis resulted in a shortlist enriched in kinases and kinesins. Biochemical studies on the kinesins confirmed KIFC1, KIF18A, KIF2C, and KIF4A as APC/C substrates. Furthermore, we showed that the APC/C(CDH1)-dependent degradation of KIFC1 regulates the bipolar spindle formation and proper cell division. A targeted quantitative proteomics experiment showed that KIFC1 degradation is modulated by a stabilizing CDK1-dependent phosphorylation site within the degradation motif of KIFC1. The regulation of KIFC1 (de-)phosphorylation and degradation provides insights into the fidelity and proper ordering of substrate degradation by the APC/C during mitosis.
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Affiliation(s)
- Sasha A Singh
- Department of Pathology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
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23
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Lianga N, Williams EC, Kennedy EK, Doré C, Pilon S, Girard SL, Deneault JS, Rudner AD. A Wee1 checkpoint inhibits anaphase onset. ACTA ACUST UNITED AC 2013; 201:843-62. [PMID: 23751495 PMCID: PMC3678162 DOI: 10.1083/jcb.201212038] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The budding yeast Wee1 kinase Swe1 restrains the metaphase-to-anaphase transition by preventing the Cdk1-dependent phosphorylation and activation of APCCdc20. Cdk1 drives both mitotic entry and the metaphase-to-anaphase transition. Past work has shown that Wee1 inhibition of Cdk1 blocks mitotic entry. Here we show that the budding yeast Wee1 kinase, Swe1, also restrains the metaphase-to-anaphase transition by preventing Cdk1 phosphorylation and activation of the mitotic form of the anaphase-promoting complex/cyclosome (APCCdc20). Deletion of SWE1 or its opposing phosphatase MIH1 (the budding yeast cdc25+) altered the timing of anaphase onset, and activation of the Swe1-dependent morphogenesis checkpoint or overexpression of Swe1 blocked cells in metaphase with reduced APC activity in vivo and in vitro. The morphogenesis checkpoint also depended on Cdc55, a regulatory subunit of protein phosphatase 2A (PP2A). cdc55Δ checkpoint defects were rescued by mutating 12 Cdk1 phosphorylation sites on the APC, demonstrating that the APC is a target of this checkpoint. These data suggest a model in which stepwise activation of Cdk1 and inhibition of PP2ACdc55 triggers anaphase onset.
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Affiliation(s)
- Noel Lianga
- Ottawa Institute of Systems Biology and Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
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24
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Ni W, Xu SL, Chalkley RJ, Pham TND, Guan S, Maltby DA, Burlingame AL, Wang ZY, Quail PH. Multisite light-induced phosphorylation of the transcription factor PIF3 is necessary for both its rapid degradation and concomitant negative feedback modulation of photoreceptor phyB levels in Arabidopsis. THE PLANT CELL 2013; 25:2679-98. [PMID: 23903316 PMCID: PMC3753391 DOI: 10.1105/tpc.113.112342] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2013] [Revised: 06/26/2013] [Accepted: 07/11/2013] [Indexed: 05/17/2023]
Abstract
Plants constantly monitor informational light signals using sensory photoreceptors, which include the phytochrome (phy) family (phyA to phyE), and adjust their growth and development accordingly. Following light-induced nuclear translocation, photoactivated phy molecules bind to and induce rapid phosphorylation and degradation of phy-interacting basic Helix Loop Helix (bHLH) transcription factors (PIFs), such as PIF3, thereby regulating the expression of target genes. However, the mechanisms underlying the signal-relay process are still not fully understood. Here, using mass spectrometry, we identify multiple, in vivo, light-induced Ser/Thr phosphorylation sites in PIF3. Using transgenic expression of site-directed mutants of PIF3, we provide evidence that a set of these phosphorylation events acts collectively to trigger rapid degradation of the PIF3 protein in response to initial exposure of dark-grown seedlings to light. In addition, we show that phyB-induced PIF3 phosphorylation is also required for the known negative feedback modulation of phyB levels in prolonged light, potentially through codegradation of phyB and PIF3. This mutually regulatory intermolecular transaction thus provides a mechanism with the dual capacity to promote early, graded, or threshold regulation of the primary, PIF3-controlled transcriptional network in response to initial light exposure, and later, to attenuate global sensitivity to the light signal through reductions in photoreceptor levels upon prolonged exposure.
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Affiliation(s)
- Weimin Ni
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720
- U.S. Department of Agriculture/Agriculture Research Service, Plant Gene Expression Center, Albany, California 94710
| | - Shou-Ling Xu
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94143
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - Robert J. Chalkley
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94143
| | - Thao Nguyen D. Pham
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720
- U.S. Department of Agriculture/Agriculture Research Service, Plant Gene Expression Center, Albany, California 94710
| | - Shenheng Guan
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94143
| | - Dave A. Maltby
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94143
| | - Alma L. Burlingame
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94143
| | - Zhi-Yong Wang
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - Peter H. Quail
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720
- U.S. Department of Agriculture/Agriculture Research Service, Plant Gene Expression Center, Albany, California 94710
- Address correspondence to
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25
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Abstract
The anaphase-promoting complex or cyclosome (APC/C) is a conserved, multisubunit E3 ubiquitin (Ub) ligase that is active both in dividing and in postmitotic cells. Its contributions to life are especially well studied in the domain of cell division, in which the APC/C lies at the epicenter of a regulatory network that controls the directionality and timing of cell cycle events. Biochemical and structural work is shedding light on the overall organization of APC/C subunits and on the mechanism of substrate recognition and Ub chain initiation and extension as well as on the molecular mechanisms of a checkpoint that seizes control of APC/C activity during mitosis. Here, we review how these recent advancements are modifying our understanding of the APC/C.
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Affiliation(s)
- Ivana Primorac
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
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26
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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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27
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Levy ED, Michnick SW, Landry CR. Protein abundance is key to distinguish promiscuous from functional phosphorylation based on evolutionary information. Philos Trans R Soc Lond B Biol Sci 2012; 367:2594-606. [PMID: 22889910 DOI: 10.1098/rstb.2012.0078] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
In eukaryotic cells, protein phosphorylation is an important and widespread mechanism used to regulate protein function. Yet, of the thousands of phosphosites identified to date, only a few hundred at best have a characterized function. It was recently shown that these functional sites are significantly more conserved than phosphosites of unknown function, stressing the importance of considering evolutionary conservation in assessing the global functional landscape of phosphosites. This leads us to review studies that examined the impact of phosphorylation on evolutionary conservation. While all these studies have shown that conservation is greater among phosphorylated sites compared with non-phosphorylated ones, the magnitude of this difference varies greatly. Further, not all studies have considered key factors that may influence the rate of phosphosite evolution. Such key factors are their localization in ordered or disordered regions, their stoichiometry or the abundance of their corresponding protein. Here we take into account all of these factors simultaneously, which reveals remarkable evolutionary patterns. First, while it is well established that protein conservation increases with abundance, we show that phosphosites partly follow an opposite trend. More precisely, Saccharomyces cerevisiae phosphosites present among abundant proteins are 1.5 times more likely to diverge in the closely related species Saccharomyces bayanus when compared with phosphosites present in the 5 per cent least abundant proteins. Second, we show that conservation is coupled to stoichiometry, whereby sites frequently phosphorylated are more conserved than those rarely phosphorylated. Finally, we provide a model of functional and noisy or 'accidental' phosphorylation that explains these observations.
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Affiliation(s)
- Emmanuel D Levy
- Département de Biochimie, Université de Montréal, Montréal, Québec, Canada.
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28
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Boehm ME, Seidler J, Hahn B, Lehmann WD. Site-specific degree of phosphorylation in proteins measured by liquid chromatography-electrospray mass spectrometry. Proteomics 2012; 12:2167-78. [PMID: 22653803 DOI: 10.1002/pmic.201100561] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
This review focuses on quantitative protein phosphorylation analysis based on coverage of both the phosphorylated and nonphosphorylated forms. In this way, site-specific data on the degree of phosphorylation can be measured, generating the most detailed level of phosphorylation status analysis of proteins. To highlight the experimental challenges in this type of quantitative protein phosphorylation analysis, we discuss the typical workflows for mass spectrometry-based proteomics with a focus on the quantitative analysis of peptide/phosphopeptide ratios. We review workflows for measuring site-specific degrees of phosphorylation including the label-free approach, differential stable isotope labeling of analytes, and methods based on the addition of stable isotope labeled peptide/phosphopeptide pairs as internal standards. The discussion also includes the determination of phosphopeptide isoform abundance data for multiply phosphorylated motifs that contain information about the connectivity of phosphorylation events. The review closes with a prospective on the use of intact stable isotope labeled proteins as internal standards and a summarizing discussion of the typical accuracies of the individual methods.
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Affiliation(s)
- Martin E Boehm
- Molecular Structure Analysis, German Cancer Research Center (DKFZ), Heidelberg, Germany
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29
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Abstract
A protein molecule exists as a heterogeneous population of posttranslationally modified forms, which are of potential interest to biologists. However, due to detection or methodology limitations, they remain uncharacterized. When a protein does become a prioritized interest in a laboratory, workflows aimed for its purification and characterization are implemented. Inherent in these workflows is the enrichment of the protein from the biological lysate, rendering it an ideal sample for mass spectrometry (MS), as detection of several peptides is greatly increased. In order to capitalize on this enhanced detection of the protein of interest, we have developed a full-length expressed protein quantification standard (FLEXIQuant standard) that is in vitro synthesized, devoid of posttranslational modifications (PTMs), and implemented into the purification workflow of the endogenous counterpart-as such it serves as an internal MS standard. FLEXIQuantification allows for the unbiased identification of peptides undergoing PTM as a function of a particular biological state. The extent of PTM is also quantified, providing further insight into the regulation of the protein.
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Affiliation(s)
- Sasha Singh
- Department of Pathology, Children's Hospital Boston and Harvard Medical School, Boston, MA, USA
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30
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Analysing signalling networks by mass spectrometry. Amino Acids 2012; 43:1061-74. [PMID: 22821269 DOI: 10.1007/s00726-012-1293-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2011] [Accepted: 04/03/2012] [Indexed: 12/31/2022]
Abstract
Sequence analysis of the human genome and the association of genetic aberrations with diseases have provided a rough framework whereby the impact of individual genotypes can be assessed. To fully understand the effect of individual and co-occurring genetic aberrations, as well as their individual and collected contribution to the development of diseases, it is critical to analyse the matching proteome and to determine how the organisation, expression level and function of protein networks are affected. Sensitive mass spectrometric platforms in combination with innovative workflows allow qualitative and quantitative analyses of the cellular as well as the extracellular proteome. Importantly, in addition to specifically identifying the content of the proteome, several aspects of the proteomic organisation can be analysed including protein complexes, protein modifications, enzymatic activities and subcellular/organelle localisation. Together, these measurements will provide novel insight into the biological effect of disease-causing mutations ultimately coupling genotype and phenotype.
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31
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Li Y, Shu Y, Peng C, Zhu L, Guo G, Li N. Absolute quantitation of isoforms of post-translationally modified proteins in transgenic organism. Mol Cell Proteomics 2012; 11:272-85. [PMID: 22442259 DOI: 10.1074/mcp.m111.016568] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Post-translational modification isoforms of a protein are known to play versatile biological functions in diverse cellular processes. To measure the molar amount of each post-translational modification isoform (P(isf)) of a target protein present in the total protein extract using mass spectrometry, a quantitative proteomic protocol, absolute quantitation of isoforms of post-translationally modified proteins (AQUIP), was developed. A recombinant ERF110 gene overexpression transgenic Arabidopsis plant was used as the model organism for demonstration of the proof of concept. Both Ser-62-independent (14)N-coded synthetic peptide standards and (15)N-coded ERF110 protein standard isolated from the heavy nitrogen-labeled transgenic plants were employed simultaneously to determine the concentration of all isoforms (T(isf)) of ERF110 in the whole plant cell lysate, whereas a pair of Ser-62-dependent synthetic peptide standards were used to quantitate the Ser-62 phosphosite occupancy (R(aqu)). The P(isf) was finally determined by integrating the two empirically measured variables using the following equation: P(isf) = T(isf) · R(aqu). The absolute amount of Ser-62-phosphorylated isoform of ERF110 determined using AQUIP was substantiated with a stable isotope labeling in Arabidopsis-based relative and accurate quantitative proteomic approach. The biological role of the Ser-62-phosphorylated isoform was demonstrated in transgenic plants.
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Affiliation(s)
- Yaojun Li
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
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32
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Jia W, Andaya A, Leary JA. Novel mass spectrometric method for phosphorylation quantification using cerium oxide nanoparticles and tandem mass tags. Anal Chem 2012; 84:2466-73. [PMID: 22304650 DOI: 10.1021/ac203248s] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The stoichiometry of protein phosphorylation significantly impacts protein function. The development of quantitative techniques in mass spectrometry has generated the ability to systematically monitor the regulation levels of various proteins. This study reports an integrated methodology using cerium oxide nanoparticles and isobaric tandem mass tag (TMT) labeling to assess absolute stoichiometries of protein phosphorylation. This protocol was designed to directly measure the dephosphorylation levels for a known phosphorylation site, therefore allowing for quantification of phosphosites. Both the accuracy and precision of the method were verified using standard peptides and protein tryptic digests. This novel method was then applied to quantify phosphorylations on eukaryotic initiation factor 3H (eIF3H), a protein integral to overall eukaryotic protein translation initiation. To date, this is the first report of assessment of protein phosphorylation quantification on eIF3.
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Affiliation(s)
- Weitao Jia
- Department of Molecular and Cellular Biology, University of California, Davis, One Shields Avenue, Davis, California 95616, USA
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33
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Zhu L, Li N. Quantitation, networking, and function of protein phosphorylation in plant cell. FRONTIERS IN PLANT SCIENCE 2012; 3:302. [PMID: 23316209 PMCID: PMC3539650 DOI: 10.3389/fpls.2012.00302] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Accepted: 12/16/2012] [Indexed: 05/08/2023]
Abstract
Protein phosphorylation is one of the most important post-translational modifications (PTMs) as it participates in regulating various cellular processes and biological functions. It is therefore crucial to identify phosphorylated proteins to construct a phosphor-relay network, and eventually to understand the underlying molecular regulatory mechanism in response to both internal and external stimuli. The changes in phosphorylation status at these novel phosphosites can be accurately measured using a (15)N-stable isotopic labeling in Arabidopsis (SILIA) quantitative proteomic approach in a high-throughput manner. One of the unique characteristics of the SILIA quantitative phosphoproteomic approach is the preservation of native PTM status on protein during the entire peptide preparation procedure. Evolved from SILIA is another quantitative PTM proteomic approach, AQUIP (absolute quantitation of isoforms of post-translationally modified proteins), which was developed by combining the advantages of targeted proteomics with SILIA. Bioinformatics-based phosphorylation site prediction coupled with an MS-based in vitro kinase assay is an additional way to extend the capability of phosphosite identification from the total cellular protein. The combined use of SILIA and AQUIP provides a novel strategy for molecular systems biological study and for investigation of in vivo biological functions of these phosphoprotein isoforms and combinatorial codes of PTMs.
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Affiliation(s)
- Lin Zhu
- *Correspondence: Lin Zhu, Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China. e-mail: ;
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34
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Ozlü N, Kirchner M, Steen JJ. Measuring phosphorylation-specific changes in response to kinase inhibitors in mammalian cells using quantitative proteomics. Methods Mol Biol 2012; 795:217-231. [PMID: 21960226 DOI: 10.1007/978-1-61779-337-0_15] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Many cancers have been associated with the deregulation of kinases, and thus, kinases have become a prime target for the development of cancer treatments. This focus on kinases has resulted in the approval of several small-molecule kinase inhibitors for cancer treatments. Further, the use of these inhibitors as tools to study cancer has provided valuable information about biological mechanisms. However, to date, not much is known about the global effects of kinases on the proteome or phosphoproteome. In this protocol, we describe methodology to study the impact of kinase inhibitors on the proteome and phosphoproteome using mass spectrometry-based quantitative proteomics. More specifically, we focus on the effects of Aurora B kinase inhibitors on the proteome, cytoskeleton proteome, the phosphoproteome, and the cytoskeleton phosphoproteome during cell cycle. This methodology is easily extended to other biological studies whose aim is to study the global proteomic effects of a kinase inhibitor.
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Affiliation(s)
- Nurhan Ozlü
- Center for Life Science, F.M. Kirby Center for Neurobiology, Children's Hospital Boston, Istanbul, Turkey
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35
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Wang Y, Guan S, Acharya P, Liu Y, Thirumaran RK, Brandman R, Schuetz EG, Burlingame AL, Correia MA. Multisite phosphorylation of human liver cytochrome P450 3A4 enhances Its gp78- and CHIP-mediated ubiquitination: a pivotal role of its Ser-478 residue in the gp78-catalyzed reaction. Mol Cell Proteomics 2011; 11:M111.010132. [PMID: 22101235 DOI: 10.1074/mcp.m111.010132] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
CYP3A4, an integral endoplasmic reticulum (ER)-anchored protein, is the major human liver cytochrome P450 enzyme responsible for the disposition of over 50% of clinically relevant drugs. Alterations of its protein turnover can influence drug metabolism, drug-drug interactions, and the bioavailability of chemotherapeutic drugs. Such CYP3A4 turnover occurs via a classical ER-associated degradation (ERAD) process involving ubiquitination by both UBC7/gp78 and UbcH5a/CHIP E2-E3 complexes for 26 S proteasomal targeting. These E3 ligases act sequentially and cooperatively in CYP3A4 ERAD because RNA interference knockdown of each in cultured hepatocytes results in the stabilization of a functionally active enzyme. We have documented that UBC7/gp78-mediated CYP3A4 ubiquitination requires protein phosphorylation by protein kinase (PK) A and PKC and identified three residues (Ser-478, Thr-264, and Ser-420) whose phosphorylation is required for intracellular CYP3A4 ERAD. We document herein that of these, Ser-478 plays a pivotal role in UBC7/gp78-mediated CYP3A4 ubiquitination, which is accelerated and enhanced on its mutation to the phosphomimetic Asp residue but attenuated on its Ala mutation. Intriguingly, CYP3A5, a polymorphically expressed human liver CYP3A4 isoform (containing Asp-478) is ubiquitinated but not degraded to a greater extent than CYP3A4 in HepG2 cells. This suggests that although Ser-478 phosphorylation is essential for UBC7/gp78-mediated CYP3A4 ubiquitination, it is not sufficient for its ERAD. Additionally, we now report that CYP3A4 protein phosphorylation by PKA and/or PKC at sites other than Ser-478, Thr-264, and Ser-420 also enhances UbcH5a/CHIP-mediated ubiquitination. Through proteomic analyses, we identify (i) 12 additional phosphorylation sites that may be involved in CHIP-CYP3A4 interactions and (ii) 8 previously unidentified CYP3A4 ubiquitination sites within spatially associated clusters of Asp/Glu and phosphorylatable Ser/Thr residues that may serve to engage each E2-E3 complex. Collectively, our findings underscore the interplay between protein phosphorylation and ubiquitination in ERAD and, to our knowledge, provide the very first example of gp78 substrate recognition via protein phosphorylation.
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Affiliation(s)
- YongQiang Wang
- Department of Cellular & Molecular Pharmacology, University of California, San Francisco, California 94158-2517, USA
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36
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Hegemann B, Hutchins JRA, Hudecz O, Novatchkova M, Rameseder J, Sykora MM, Liu S, Mazanek M, Lénárt P, Hériché JK, Poser I, Kraut N, Hyman AA, Yaffe MB, Mechtler K, Peters JM. Systematic phosphorylation analysis of human mitotic protein complexes. Sci Signal 2011; 4:rs12. [PMID: 22067460 DOI: 10.1126/scisignal.2001993] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Progression through mitosis depends on a large number of protein complexes that regulate the major structural and physiological changes necessary for faithful chromosome segregation. Most, if not all, of the mitotic processes are regulated by a set of mitotic protein kinases that control protein activity by phosphorylation. Although many mitotic phosphorylation events have been identified in proteome-scale mass spectrometry studies, information on how these phosphorylation sites are distributed within mitotic protein complexes and which kinases generate these phosphorylation sites is largely lacking. We used systematic protein-affinity purification combined with mass spectrometry to identify 1818 phosphorylation sites in more than 100 mitotic protein complexes. In many complexes, the phosphorylation sites were concentrated on a few subunits, suggesting that these subunits serve as "switchboards" to relay the kinase-regulatory signals within the complexes. Consequent bioinformatic analyses identified potential kinase-substrate relationships for most of these sites. In a subsequent in-depth analysis of key mitotic regulatory complexes with the Aurora kinase B (AURKB) inhibitor Hesperadin and a new Polo-like kinase (PLK1) inhibitor, BI 4834, we determined the kinase dependency for 172 phosphorylation sites on 41 proteins. Combination of the results of the cellular studies with Scansite motif prediction enabled us to identify 14 sites on six proteins as direct candidate substrates of AURKB or PLK1.
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Affiliation(s)
- Björn Hegemann
- Research Institute of Molecular Pathology, Dr. Bohr-Gasse 7, 1030 Vienna, Austria
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37
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López E, Wesselink JJ, López I, Mendieta J, Gómez-Puertas P, Muñoz SR. Technical phosphoproteomic and bioinformatic tools useful in cancer research. J Clin Bioinforma 2011; 1:26. [PMID: 21967744 PMCID: PMC3195713 DOI: 10.1186/2043-9113-1-26] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Accepted: 10/03/2011] [Indexed: 12/22/2022] Open
Abstract
Reversible protein phosphorylation is one of the most important forms of cellular regulation. Thus, phosphoproteomic analysis of protein phosphorylation in cells is a powerful tool to evaluate cell functional status. The importance of protein kinase-regulated signal transduction pathways in human cancer has led to the development of drugs that inhibit protein kinases at the apex or intermediary levels of these pathways. Phosphoproteomic analysis of these signalling pathways will provide important insights for operation and connectivity of these pathways to facilitate identification of the best targets for cancer therapies. Enrichment of phosphorylated proteins or peptides from tissue or bodily fluid samples is required. The application of technologies such as phosphoenrichments, mass spectrometry (MS) coupled to bioinformatics tools is crucial for the identification and quantification of protein phosphorylation sites for advancing in such relevant clinical research. A combination of different phosphopeptide enrichments, quantitative techniques and bioinformatic tools is necessary to achieve good phospho-regulation data and good structural analysis of protein studies. The current and most useful proteomics and bioinformatics techniques will be explained with research examples. Our aim in this article is to be helpful for cancer research via detailing proteomics and bioinformatic tools.
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Affiliation(s)
- Elena López
- Centro de Investigación i+12 del Hospital Universitario 12 de Octubre, Avda de Córdoba s/n Madrid, 28041, Spain
| | - Jan-Jaap Wesselink
- Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM) Campus de Cantoblanco, c/Nicolás Cabrera, 1, 28049 Madrid, Spain.,Biomol-Informatics, S.L., Parque Científico de Madrid, Campus de Cantoblanco, c/Faraday 7, 28049 Madrid, Spain
| | - Isabel López
- Servicio de Hematología Hospital QUIRÓN, Madrid, Diego de Velázquez 1 28223, Pozuelo Madrid Spain
| | - Jesús Mendieta
- Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM) Campus de Cantoblanco, c/Nicolás Cabrera, 1, 28049 Madrid, Spain.,Biomol-Informatics, S.L., Parque Científico de Madrid, Campus de Cantoblanco, c/Faraday 7, 28049 Madrid, Spain
| | - Paulino Gómez-Puertas
- Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM) Campus de Cantoblanco, c/Nicolás Cabrera, 1, 28049 Madrid, Spain
| | - Sarbelio Rodríguez Muñoz
- Servicio de Digestivo, Hospital Universitario 12 Octubre, Avda de Córdoba s/n Madrid, 28041, Spain
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38
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Eissler CL, Bremmer SC, Martinez JS, Parker LL, Charbonneau H, Hall MC. A general strategy for studying multisite protein phosphorylation using label-free selected reaction monitoring mass spectrometry. Anal Biochem 2011; 418:267-75. [PMID: 21810403 DOI: 10.1016/j.ab.2011.07.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Revised: 07/14/2011] [Accepted: 07/15/2011] [Indexed: 01/26/2023]
Abstract
The majority of eukaryotic proteins are phosphorylated in vivo, and phosphorylation may be the most common regulatory posttranslational modification. Many proteins are phosphorylated at numerous sites, often by multiple kinases, which may have different functional consequences. Understanding biological functions of phosphorylation events requires methods to detect and quantify individual sites within a substrate. Here we outline a general strategy that addresses this need and relies on the high sensitivity and specificity of selected reaction monitoring (SRM) mass spectrometry, making it potentially useful for studying in vivo phosphorylation without the need to isolate target proteins. Our approach uses label-free quantification for simplicity and general applicability, although it is equally compatible with stable isotope quantification methods. We demonstrate that label-free SRM-based quantification is comparable to conventional assays for measuring the kinetics of phosphatase and kinase reactions in vitro. We also demonstrate the capability of this method to simultaneously measure relative rates of phosphorylation and dephosphorylation of substrate mixtures, including individual sites on intact protein substrates in the context of a whole cell extract. This strategy should be particularly useful for characterizing the physiological substrate specificity of kinases and phosphatases and can be applied to studies of other protein modifications as well.
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Affiliation(s)
- Christie L Eissler
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
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39
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Wu R, Haas W, Dephoure N, Huttlin EL, Zhai B, Sowa ME, Gygi SP. A large-scale method to measure absolute protein phosphorylation stoichiometries. Nat Methods 2011; 8:677-83. [PMID: 21725298 PMCID: PMC3146562 DOI: 10.1038/nmeth.1636] [Citation(s) in RCA: 228] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Accepted: 05/11/2011] [Indexed: 12/22/2022]
Abstract
The underlying functional role of protein phosphorylation is impacted by its fractional stoichiometry. Thus, a comprehensive strategy to study phosphorylation dynamics should include an assessment of site stoichiometry. Here, we developed an integrated method that relies on phosphatase treatment and stable isotope labeling to determine the absolute stoichiometries of protein phosphorylation on a large-scale. This approach requires the measurement of only a single ratio relating phosphatase- and mock-treated samples. We applied the strategy to determine stoichiometries for 5,033 phosphorylation sites in Saccharomyces cerevisiae. Stoichiometries were determined from biological triplicate experiments with good reproducibility. We validated ten sites stoichiometries representing the full range of values with an absolute quantitative approach, showing excellent agreement. Using bioinformatics, we characterized the biological properties associated with phosphorylation sites with vastly differing absolute stoichiometries.
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Affiliation(s)
- Ronghu Wu
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, USA
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40
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López E, López I, Ferreira A, Sequí J. Clinical and technical phosphoproteomic research. Proteome Sci 2011; 9:27. [PMID: 21635771 PMCID: PMC3127965 DOI: 10.1186/1477-5956-9-27] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Accepted: 06/02/2011] [Indexed: 12/11/2022] Open
Abstract
An encouraging approach for the diagnosis and effective therapy of immunological pathologies, which would include cancer, is the identification of proteins and phosphorylated proteins. Disease proteomics, in particular, is a potentially useful method for this purpose. A key role is played by protein phosphorylation in the regulation of normal immunology disorders and targets for several new cancer drugs and drug candidates are cancer cells and protein kinases. Protein phosphorylation is a highly dynamic process. The functioning of new drugs is of major importance as is the selection of those patients who would respond best to a specific treatment regime. In all major aspects of cellular life signalling networks are key elements which play a major role in inter- and intracellular communications. They are involved in diverse processes such as cell-cycle progression, cellular metabolism, cell-cell communication and appropriate response to the cellular environment. A whole range of networks that are involved in the regulation of cell development, differentiation, proliferation, apoptosis, and immunologic responses is contained in the latter. It is so necessary to understand and monitor kinase signalling pathways in order to understand many immunology pathologies. Enrichment of phosphorylated proteins or peptides from tissue or bodily fluid samples is required. The application of technologies such as immunoproteomic techniques, phosphoenrichments and mass spectrometry (MS) is crucial for the identification and quantification of protein phosphorylation sites in order to advance in clinical research. Pharmacodynamic readouts of disease states and cellular drug responses in tumour samples will be provided as the field develops. We aim to detail the current and most useful techniques with research examples to isolate and carry out clinical phosphoproteomic studies which may be helpful for immunology and cancer research. Different phosphopeptide enrichment and quantitative techniques need to be combined to achieve good phosphopeptide recovery and good up- and-down phospho-regulation protein studies.
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Affiliation(s)
- Elena López
- Inflammatory core, Centro de Investigación i+12 del Hospital Universitario 12 de Octubre, Avda de Córdoba s/n 28041, Madrid, Spain
| | - Isabel López
- Hematology Department, Hospital Universitario 12 Octubre, Avda de Córdoba s/n 28041, Madrid, Spain
| | - Antonio Ferreira
- Immunology Department, Hospital Universitario La Paz, P° de la Castellana 261-28046, Madrid, Spain
| | - Julia Sequí
- Immunology Department, Hospital Carlos III, Sinesio Delgado 28029, Madrid, Spain
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Izawa D, Pines J. How APC/C-Cdc20 changes its substrate specificity in mitosis. Nat Cell Biol 2011; 13:223-33. [PMID: 21336306 PMCID: PMC3059483 DOI: 10.1038/ncb2165] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2010] [Accepted: 11/26/2010] [Indexed: 01/26/2023]
Abstract
Progress through mitosis requires that the right protein be degraded at the right time. One ubiquitin ligase, the anaphase-promoting complex or cyclosome (APC/C) targets most of the crucial mitotic regulators by changing its substrate specificity throughout mitosis. The spindle assembly checkpoint (SAC) acts on the APC/C co-activator, Cdc20 (cell division cycle 20), to block the degradation of metaphase substrates (for example, cyclin B1 and securin), but not others (for example, cyclin A). How this is achieved is unclear. Here we show that Cdc20 binds to different sites on the APC/C depending on the SAC. Cdc20 requires APC3 and APC8 to bind and activate the APC/C when the SAC is satisfied, but requires only APC8 to bind the APC/C when the SAC is active. Moreover, APC10 is crucial for the destruction of cyclin B1 and securin, but not cyclin A. We conclude that the SAC causes Cdc20 to bind to different sites on the APC/C and this alters APC/C substrate specificity.
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Affiliation(s)
- Daisuke Izawa
- Gurdon Institute and Department of Zoology, Tennis Court Road,Cambridge CB2 1QN, UK
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Schreiber A, Stengel F, Zhang Z, Enchev RI, Kong EH, Morris EP, Robinson CV, da Fonseca PCA, Barford D. Structural basis for the subunit assembly of the anaphase-promoting complex. Nature 2011; 470:227-32. [PMID: 21307936 DOI: 10.1038/nature09756] [Citation(s) in RCA: 137] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2010] [Accepted: 12/14/2010] [Indexed: 12/18/2022]
Abstract
The anaphase-promoting complex or cyclosome (APC/C) is an unusually large E3 ubiquitin ligase responsible for regulating defined cell cycle transitions. Information on how its 13 constituent proteins are assembled, and how they interact with co-activators, substrates and regulatory proteins is limited. Here, we describe a recombinant expression system that allows the reconstitution of holo APC/C and its sub-complexes that, when combined with electron microscopy, mass spectrometry and docking of crystallographic and homology-derived coordinates, provides a precise definition of the organization and structure of all essential APC/C subunits, resulting in a pseudo-atomic model for 70% of the APC/C. A lattice-like appearance of the APC/C is generated by multiple repeat motifs of most APC/C subunits. Three conserved tetratricopeptide repeat (TPR) subunits (Cdc16, Cdc23 and Cdc27) share related superhelical homo-dimeric architectures that assemble to generate a quasi-symmetrical structure. Our structure explains how this TPR sub-complex, together with additional scaffolding subunits (Apc1, Apc4 and Apc5), coordinate the juxtaposition of the catalytic and substrate recognition module (Apc2, Apc11 and Apc10 (also known as Doc1)), and TPR-phosphorylation sites, relative to co-activator, regulatory proteins and substrates.
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Affiliation(s)
- Anne Schreiber
- Section of Structural Biology, Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London, SW3 6JB, UK
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Potapova TA, Sivakumar S, Flynn JN, Li R, Gorbsky GJ. Mitotic progression becomes irreversible in prometaphase and collapses when Wee1 and Cdc25 are inhibited. Mol Biol Cell 2011; 22:1191-206. [PMID: 21325631 PMCID: PMC3078080 DOI: 10.1091/mbc.e10-07-0599] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Activation of Cdk1 is rapid and switch-like due to positive feedback mechanisms. When Cdk1 is fully on, cells are capable of M-to-G1 transition. Inhibition of positive feedback prevents rapid Cdk1 activation and induces a mitotic “collapse” phenotype characterized by the dephosphorylation of mitotic substrates without cyclin B proteolysis. Mitosis requires precise coordination of multiple global reorganizations of the nucleus and cytoplasm. Cyclin-dependent kinase 1 (Cdk1) is the primary upstream kinase that directs mitotic progression by phosphorylation of a large number of substrate proteins. Cdk1 activation reaches the peak level due to positive feedback mechanisms. By inhibiting Cdk chemically, we showed that, in prometaphase, when Cdk1 substrates approach the peak of their phosphorylation, cells become capable of proper M-to-G1 transition. We interfered with the molecular components of the Cdk1-activating feedback system through use of chemical inhibitors of Wee1 and Myt1 kinases and Cdc25 phosphatases. Inhibition of Wee1 and Myt1 at the end of the S phase led to rapid Cdk1 activation and morphologically normal mitotic entry, even in the absence of G2. Dampening Cdc25 phosphatases simultaneously with Wee1 and Myt1 inhibition prevented Cdk1/cyclin B kinase activation and full substrate phosphorylation and induced a mitotic “collapse,” a terminal state characterized by the dephosphorylation of mitotic substrates without cyclin B proteolysis. This was blocked by the PP1/PP2A phosphatase inhibitor, okadaic acid. These findings suggest that the positive feedback in Cdk activation serves to overcome the activity of Cdk-opposing phosphatases and thus sustains forward progression in mitosis.
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Hu Y, Peng Y, Lin K, Shen H, Brousseau LC, Sakamoto J, Sun T, Ferrari M. Surface engineering on mesoporous silica chips for enriching low molecular weight phosphorylated proteins. NANOSCALE 2011; 3:421-8. [PMID: 21135976 PMCID: PMC3397147 DOI: 10.1039/c0nr00720j] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Phosphorylated peptides and proteins play an important role in normal cellular activities, e.g., gene expression, mitosis, differentiation, proliferation, and apoptosis, as well as tumor initiation, progression and metastasis. However, technical hurdles hinder the use of common fractionation methods to capture phosphopeptides from complex biological fluids such as human sera. Herein, we present the development of a dual strategy material that offers enhanced capture of low molecular weight phosphoproteins: mesoporous silica thin films with precisely engineered pore sizes that sterically select for molecular size combined with chemically selective surface modifications (i.e. Ga3+, Ti4+ and Zr4+) that target phosphoroproteins. These materials provide high reproducibility (CV=18%) and increase the stability of the captured proteins by excluding degrading enzymes, such as trypsin. The chemical and physical properties of the composite mesoporous thin films were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy and ellipsometry. Using mass spectroscopy and biostatistics analysis, the enrichment efficiency of different metal ions immobilized on mesoporous silica chips was investigated. The novel technology reported provides a platform capable of efficiently profiling the serum proteome for biomarker discovery, forensic sampling, and routine diagnostic applications.
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Affiliation(s)
- Ye Hu
- Department of Nanomedicine and Biomedical Engineering, the University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Yang Peng
- Department of Nanomedicine and Biomedical Engineering, the University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Kevin Lin
- Department of Biomedical Engineering, the University of Texas at Austin, Austin, TX, USA
| | - Haifa Shen
- Department of Nanomedicine and Biomedical Engineering, the University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Louis C. Brousseau
- Department of Nanomedicine and Biomedical Engineering, the University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Jason Sakamoto
- Department of Nanomedicine and Biomedical Engineering, the University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Tong Sun
- Department of Nanomedicine and Biomedical Engineering, the University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Mauro Ferrari
- Department of Nanomedicine and Biomedical Engineering, the University of Texas Health Science Center at Houston, Houston, TX, USA
- Department of Biomedical Engineering, the University of Texas at Austin, Austin, TX, USA
- The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Department of Bioengineering, Rice University, Houston, TX, USA
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McLean JR, Chaix D, Ohi MD, Gould KL. State of the APC/C: organization, function, and structure. Crit Rev Biochem Mol Biol 2011; 46:118-36. [PMID: 21261459 DOI: 10.3109/10409238.2010.541420] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The ubiquitin-proteasome protein degradation system is involved in many essential cellular processes including cell cycle regulation, cell differentiation, and the unfolded protein response. The anaphase-promoting complex/cyclosome (APC/C), an evolutionarily conserved E3 ubiquitin ligase, was discovered 15 years ago because of its pivotal role in cyclin degradation and mitotic progression. Since then, we have learned that the APC/C is a very large, complex E3 ligase composed of 13 subunits, yielding a molecular machine of approximately 1 MDa. The intricate regulation of the APC/C is mediated by the Cdc20 family of activators, pseudosubstrate inhibitors, protein kinases and phosphatases and the spindle assembly checkpoint. The large size, complexity, and dynamic nature of the APC/C represent significant obstacles toward high-resolution structural techniques; however, over the last decade, there have been a number of lower resolution APC/C structures determined using single particle electron microscopy. These structures, when combined with data generated from numerous genetic and biochemical studies, have begun to shed light on how APC/C activity is regulated. Here, we discuss the most recent developments in the APC/C field concerning structure, substrate recognition, and catalysis.
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Affiliation(s)
- Janel R McLean
- Howard Hughes Medical Institute, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
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Wang Y, Guan S, Acharya P, Koop DR, Liu Y, Liao M, Burlingame AL, Correia MA. Ubiquitin-dependent proteasomal degradation of human liver cytochrome P450 2E1: identification of sites targeted for phosphorylation and ubiquitination. J Biol Chem 2011; 286:9443-56. [PMID: 21209460 DOI: 10.1074/jbc.m110.176685] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human liver CYP2E1 is a monotopic, endoplasmic reticulum-anchored cytochrome P450 responsible for the biotransformation of clinically relevant drugs, low molecular weight xenobiotics, carcinogens, and endogenous ketones. CYP2E1 substrate complexation converts it into a stable slow-turnover species degraded largely via autophagic lysosomal degradation. Substrate decomplexation/withdrawal results in a fast turnover CYP2E1 species, putatively generated through its futile oxidative cycling, that incurs endoplasmic reticulum-associated ubiquitin-dependent proteasomal degradation (UPD). CYP2E1 thus exhibits biphasic turnover in the mammalian liver. We now show upon heterologous expression of human CYP2E1 in Saccharomyces cerevisiae that its autophagic lysosomal degradation and UPD pathways are evolutionarily conserved, even though its potential for futile catalytic cycling is low due to its sluggish catalytic activity in yeast. This suggested that other factors (i.e. post-translational modifications or "degrons") contribute to its UPD. Indeed, in cultured human hepatocytes, CYP2E1 is detectably ubiquitinated, and this is enhanced on its mechanism-based inactivation. Studies in Ubc7p and Ubc5p genetically deficient yeast strains versus corresponding isogenic wild types identified these ubiquitin-conjugating E2 enzymes as relevant to CYP2E1 UPD. Consistent with this, in vitro functional reconstitution analyses revealed that mammalian UBC7/gp78 and UbcH5a/CHIP E2-E3 ubiquitin ligases were capable of ubiquitinating CYP2E1, a process enhanced by protein kinase (PK) A and/or PKC inclusion. Inhibition of PKA or PKC blocked intracellular CYP2E1 ubiquitination and turnover. Here, through mass spectrometric analyses, we identify some CYP2E1 phosphorylation/ubiquitination sites in spatially associated clusters. We propose that these CYP2E1 phosphorylation clusters may serve to engage each E2-E3 ubiquitination complex in vitro and intracellularly.
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Affiliation(s)
- YongQiang Wang
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California 94158-2517, USA
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Song L, Rape M. Substrate-specific regulation of ubiquitination by the anaphase-promoting complex. Cell Cycle 2011; 10:52-6. [PMID: 21191176 DOI: 10.4161/cc.10.1.14387] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
By orchestrating the sequential degradation of a large number of cell cycle regulators, the ubiquitin ligase anaphase-promoting complex (APC/C) is essential for proliferation in all eukaryotes. The correct timing of APC/C-dependent substrate degradation, a critical feature of progression through mitosis, was long known to be controlled by mechanisms targeting the core APC/C-machinery. Recent experiments, however, have revealed an important contribution of substrate-specific regulation of the APC/C to achieve accurate cell division. In this perspective, we describe different mechanisms of substrate-specific APC/C-regulation and discuss their importance for cell division.
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Affiliation(s)
- Ling Song
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA, USA
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Abstract
Understanding cell growth and cell division involves the study of regulatory events that occur in a cell cycle phase-dependent manner. Studies analyzing cell cycle regulatory mechanisms and cell cycle progression invariably require synchronization of cell populations at specific cell cycle stages. Several methods have been established to synchronize cells, including serum deprivation, contact inhibition, centrifugal elutriation, and drug-dependent synchronization. Despite potential adverse cellular consequences of synchronizing cells by pharmacological agents, drug-dependent methods can be advantageous when studying later cell cycle events to ensure specific enrichment at selected mitotic stages. This chapter describes protocols used in our laboratory for isolating mitotic mammalian cells in a large-scale manner. In particular, we discuss the technical aspects of adherent or suspension cell isolation, the methods necessary to enrich cells at different mitotic stages and the optimized culture conditions.
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Affiliation(s)
- Kalyan Dulla
- Department of Molecular Diagnostics, Philips Research, Eindhoven, The Netherlands.
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49
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Abstract
AbstractThe complex molecular events responsible for coordinating chromosome replication and segregation with cell division and growth are collectively known as the cell cycle. Progression through the cell cycle is orchestrated by the interplay between controlled protein synthesis and degradation and protein phosphorylation. Protein degradation is primarily regulated through the ubiquitin proteasome system, mediated by two related E3 protein ubiquitin ligases, the Skp1 cullin F-box (SCF) and the anaphase promoting complex (also known as the cyclosome) (APC/C). The APC/C is a multi-subunit cullin-RING E3 ubiquitin ligase that regulates progression through the mitotic phase of the cell cycle and controls entry into S phase by catalysing the ubiquitylation of cyclins and other cell cycle regulatory proteins. Selection of APC/C targets is controlled through recognition of short destruction motifs, predominantly the D-box and KEN-box. APC/C-mediated coordination of cell cycle progression is achieved through the temporal regulation of APC/C activity and substrate specificity, exerted through a combination of co-activator subunits, reversible phosphorylation and inhibitory proteins and complexes. The aim of this article is to discuss the APC/C from a structural and mechanistic perspective. Although an atomic structure of the APC/C is still lacking, a combination of genetic, biochemical, electron microscopy studies of intact APC/C and crystallographic analysis of individual subunits, together with analogies to evolutionarily related E3 ligases of the RING family, has provided deep insights into the molecular mechanisms of catalysis and substrate recognition, and structural organisation of the APC/C.
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Trost M, Bridon G, Desjardins M, Thibault P. Subcellular phosphoproteomics. MASS SPECTROMETRY REVIEWS 2010; 29:962-90. [PMID: 20931658 DOI: 10.1002/mas.20297] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Protein phosphorylation represents one of the most extensively studied post-translational modifications, primarily due to the emergence of sensitive methods enabling the detection of this modification both in vitro and in vivo. The availability of enrichment methods combined with sensitive mass spectrometry instrumentation has played a crucial role in uncovering the dynamic changes and the large expanding repertoire of this reversible modification. The structural changes imparted by the phosphorylation of specific residues afford exquisite mechanisms for the regulation of protein functions by modulating new binding sites on scaffold proteins or by abrogating protein-protein interactions. However, the dynamic interplay of protein phosphorylation is not occurring randomly within the cell but is rather finely orchestrated by specific kinases and phosphatases that are unevenly distributed across subcellular compartments. This spatial separation not only regulates protein phosphorylation but can also control the activity of other enzymes and the transfer of other post-translational modifications. While numerous large-scale phosphoproteomics studies highlighted the extent and diversity of phosphoproteins present in total cell lysates, the further understanding of their regulation and biological activities require a spatio-temporal resolution only achievable through subcellular fractionation. This review presents a first account of the emerging field of subcellular phosphoproteomics where cell fractionation approaches are combined with sensitive mass spectrometry methods to facilitate the identification of low abundance proteins and to unravel the intricate regulation of protein phosphorylation.
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Affiliation(s)
- Matthias Trost
- Institute for Research in Immunology and Cancer, Université de Montréal, P.O. Box 6128, Station Centre-ville, Montréal, Québec, Canada H3C 3J7
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