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Zhang X, Sun H, Wang Z, Zhou S, Fu Y, Anthony HA, Peng J. In-Depth Blood Proteome Profiling by Extensive Fractionation and Multiplexed Quantitative Mass Spectrometry. Methods Mol Biol 2023; 2628:109-125. [PMID: 36781782 DOI: 10.1007/978-1-0716-2978-9_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
Blood in the circulatory system carries information of physiological and pathological status of the human body, so blood proteins are often used as biomarkers for diagnosis, prognosis, and therapy. Human blood proteome can be explored by the latest technologies in mass spectrometry (MS), creating an opportunity of discovering new disease biomarkers. The extreme dynamic range of protein concentrations in blood, however, poses a challenge to detect proteins of low abundance, namely, tissue leakage proteins. Here, we describe a strategy to directly analyze undepleted blood samples by extensive liquid chromatography (LC) fractionation and 18-plex tandem-mass-tag (TMT) mass spectrometry. The proteins in blood specimens (e.g., plasma or serum) are isolated by acetone precipitation and digested into peptides. The resulting peptides are TMT-labeled, separated by basic pH reverse-phase (RP) LC into at least 40 fractions, and analyzed by acidic pH RPLC and high-resolution MS/MS, leading to the quantification of ~3000 unique proteins. Further increase of basic pH RPLC fractions and adjustment of the fraction concatenation strategy can enhance the proteomic coverage (up to ~5000 proteins). Finally, the combination of multiple batches of TMT experiments allows the profiling of hundreds of blood samples. This TMT-MS-based method provides a powerful platform for deep proteome profiling of human blood samples.
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Affiliation(s)
- Xue Zhang
- Departments of Structural Biology and Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Huan Sun
- Departments of Structural Biology and Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Zhen Wang
- Departments of Structural Biology and Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Suiping Zhou
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Yingxue Fu
- Departments of Structural Biology and Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - High A Anthony
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Junmin Peng
- Departments of Structural Biology and Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA.
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, USA.
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2
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Li Y, Dammer EB, Gao Y, Lan Q, Villamil MA, Duong DM, Zhang C, Ping L, Lauinger L, Flick K, Xu Z, Wei W, Xing X, Chang L, Jin J, Hong X, Zhu Y, Wu J, Deng Z, He F, Kaiser P, Xu P. Proteomics Links Ubiquitin Chain Topology Change to Transcription Factor Activation. Mol Cell 2019; 76:126-137.e7. [PMID: 31444107 DOI: 10.1016/j.molcel.2019.07.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 05/28/2019] [Accepted: 06/28/2019] [Indexed: 12/31/2022]
Abstract
A surprising complexity of ubiquitin signaling has emerged with identification of different ubiquitin chain topologies. However, mechanisms of how the diverse ubiquitin codes control biological processes remain poorly understood. Here, we use quantitative whole-proteome mass spectrometry to identify yeast proteins that are regulated by lysine 11 (K11)-linked ubiquitin chains. The entire Met4 pathway, which links cell proliferation with sulfur amino acid metabolism, was significantly affected by K11 chains and selected for mechanistic studies. Previously, we demonstrated that a K48-linked ubiquitin chain represses the transcription factor Met4. Here, we show that efficient Met4 activation requires a K11-linked topology. Mechanistically, our results propose that the K48 chain binds to a topology-selective tandem ubiquitin binding region in Met4 and competes with binding of the basal transcription machinery to the same region. The change to K11-enriched chain architecture releases this competition and permits binding of the basal transcription complex to activate transcription.
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Affiliation(s)
- Yanchang Li
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, National Center for Protein Sciences (Beijing), Research Unit of Proteomics & Research and Development of New Drug of Chinese Academy of Medical Sciences, Institute of Lifeomics, Beijing 102206, P.R. China
| | - Eric B Dammer
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, National Center for Protein Sciences (Beijing), Research Unit of Proteomics & Research and Development of New Drug of Chinese Academy of Medical Sciences, Institute of Lifeomics, Beijing 102206, P.R. China; Center for Neurodegenerative Diseases, Emory Proteomics Service Center, and Department of Biochemistry, Emory University, Atlanta, GA 30322, USA
| | - Yuan Gao
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, National Center for Protein Sciences (Beijing), Research Unit of Proteomics & Research and Development of New Drug of Chinese Academy of Medical Sciences, Institute of Lifeomics, Beijing 102206, P.R. China
| | - Qiuyan Lan
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery of Ministry of Education, School of Pharmaceutical Sciences, School of Medicine, Wuhan University, Wuhan 430072, P.R. China
| | - Mark A Villamil
- Department of Biological Chemistry, School of Medicine, University of California, Irvine, Irvine, CA 92697-1700, USA
| | - Duc M Duong
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, National Center for Protein Sciences (Beijing), Research Unit of Proteomics & Research and Development of New Drug of Chinese Academy of Medical Sciences, Institute of Lifeomics, Beijing 102206, P.R. China; Center for Neurodegenerative Diseases, Emory Proteomics Service Center, and Department of Biochemistry, Emory University, Atlanta, GA 30322, USA
| | - Chengpu Zhang
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, National Center for Protein Sciences (Beijing), Research Unit of Proteomics & Research and Development of New Drug of Chinese Academy of Medical Sciences, Institute of Lifeomics, Beijing 102206, P.R. China
| | - Lingyan Ping
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, National Center for Protein Sciences (Beijing), Research Unit of Proteomics & Research and Development of New Drug of Chinese Academy of Medical Sciences, Institute of Lifeomics, Beijing 102206, P.R. China; Key Laboratory of Combinatorial Biosynthesis and Drug Discovery of Ministry of Education, School of Pharmaceutical Sciences, School of Medicine, Wuhan University, Wuhan 430072, P.R. China
| | - Linda Lauinger
- Department of Biological Chemistry, School of Medicine, University of California, Irvine, Irvine, CA 92697-1700, USA
| | - Karin Flick
- Department of Biological Chemistry, School of Medicine, University of California, Irvine, Irvine, CA 92697-1700, USA
| | - Zhongwei Xu
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, National Center for Protein Sciences (Beijing), Research Unit of Proteomics & Research and Development of New Drug of Chinese Academy of Medical Sciences, Institute of Lifeomics, Beijing 102206, P.R. China
| | - Wei Wei
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, National Center for Protein Sciences (Beijing), Research Unit of Proteomics & Research and Development of New Drug of Chinese Academy of Medical Sciences, Institute of Lifeomics, Beijing 102206, P.R. China
| | - Xiaohua Xing
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, National Center for Protein Sciences (Beijing), Research Unit of Proteomics & Research and Development of New Drug of Chinese Academy of Medical Sciences, Institute of Lifeomics, Beijing 102206, P.R. China
| | - Lei Chang
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, National Center for Protein Sciences (Beijing), Research Unit of Proteomics & Research and Development of New Drug of Chinese Academy of Medical Sciences, Institute of Lifeomics, Beijing 102206, P.R. China
| | - Jianping Jin
- Life Sciences Institute, Zhejiang University, Hangzhou 310058, P.R. China
| | - Xuechuan Hong
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery of Ministry of Education, School of Pharmaceutical Sciences, School of Medicine, Wuhan University, Wuhan 430072, P.R. China
| | - Yunping Zhu
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, National Center for Protein Sciences (Beijing), Research Unit of Proteomics & Research and Development of New Drug of Chinese Academy of Medical Sciences, Institute of Lifeomics, Beijing 102206, P.R. China
| | - Junzhu Wu
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery of Ministry of Education, School of Pharmaceutical Sciences, School of Medicine, Wuhan University, Wuhan 430072, P.R. China
| | - Zixin Deng
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery of Ministry of Education, School of Pharmaceutical Sciences, School of Medicine, Wuhan University, Wuhan 430072, P.R. China
| | - Fuchu He
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, National Center for Protein Sciences (Beijing), Research Unit of Proteomics & Research and Development of New Drug of Chinese Academy of Medical Sciences, Institute of Lifeomics, Beijing 102206, P.R. China.
| | - Peter Kaiser
- Department of Biological Chemistry, School of Medicine, University of California, Irvine, Irvine, CA 92697-1700, USA.
| | - Ping Xu
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, National Center for Protein Sciences (Beijing), Research Unit of Proteomics & Research and Development of New Drug of Chinese Academy of Medical Sciences, Institute of Lifeomics, Beijing 102206, P.R. China; Key Laboratory of Combinatorial Biosynthesis and Drug Discovery of Ministry of Education, School of Pharmaceutical Sciences, School of Medicine, Wuhan University, Wuhan 430072, P.R. China; Guizhou University School of Medicine, Guiyang 550025, P.R. China.
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3
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Gaczynska M, Osmulski PA. Targeting Protein-Protein Interactions in the Ubiquitin-Proteasome Pathway. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2017; 110:123-165. [PMID: 29412995 DOI: 10.1016/bs.apcsb.2017.09.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The ubiquitin-proteasome pathway (UPP) is a major venue for controlled intracellular protein degradation in Eukaryota. The machinery of several hundred proteins is involved in recognizing, tagging, transporting, and cleaving proteins, all in a highly regulated manner. Short-lived transcription factors, misfolded translation products, stress-damaged polypeptides, or worn-out long-lived proteins, all can be found among the substrates of UPP. Carefully choreographed protein-protein interactions (PPI) are involved in each step of the pathway. For many of the steps small-molecule inhibitors have been identified and often they directly or indirectly target PPI. The inhibitors may destabilize intracellular proteostasis and trigger apoptosis. So far this is the most explored option used as an anticancer strategy. Alternatively, substrate-specific polyubiquitination may be regulated for a precise intervention aimed at a particular metabolic pathway. This very attractive opportunity is moving close to clinical application. The best known drug target in UPP is the proteasome: the end point of the journey of a protein destined for degradation. The proteasome alone is a perfect object to study the mechanisms and roles of PPI on many levels. This giant protease is built from multisubunit modules and additionally utilizes a service from transient protein ligands, for example, delivering substrates. An elaborate set of PPI within the highest-order proteasome assembly is involved in substrate recognition and processing. Below we will outline PPI involved in the UPP and discuss the growing prospects for their utilization in pharmacological interventions.
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Affiliation(s)
- Maria Gaczynska
- Institute of Biotechnology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States.
| | - Pawel A Osmulski
- Institute of Biotechnology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
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4
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Su N, Zhang C, Zhang Y, Wang Z, Fan F, Zhao M, Wu F, Gao Y, Li Y, Chen L, Tian M, Zhang T, Wen B, Sensang N, Xiong Z, Wu S, Liu S, Yang P, Zhen B, Zhu Y, He F, Xu P. Special Enrichment Strategies Greatly Increase the Efficiency of Missing Proteins Identification from Regular Proteome Samples. J Proteome Res 2015; 14:3680-92. [DOI: 10.1021/acs.jproteome.5b00481] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Na Su
- State
Key Laboratory of Proteomics, Beijing Proteome Research Center, National
Engineering Research Center for Protein Drugs, National Center for
Protein Sciences, Beijing Institute of Radiation Medicine, Beijing 102206, China
| | - Chengpu Zhang
- State
Key Laboratory of Proteomics, Beijing Proteome Research Center, National
Engineering Research Center for Protein Drugs, National Center for
Protein Sciences, Beijing Institute of Radiation Medicine, Beijing 102206, China
| | - Yao Zhang
- State
Key Laboratory of Proteomics, Beijing Proteome Research Center, National
Engineering Research Center for Protein Drugs, National Center for
Protein Sciences, Beijing Institute of Radiation Medicine, Beijing 102206, China
- Institute
of Microbiology, Chinese Academy of Science, Beijing 100101, China
| | - Zhiqiang Wang
- State
Key Laboratory of Proteomics, Beijing Proteome Research Center, National
Engineering Research Center for Protein Drugs, National Center for
Protein Sciences, Beijing Institute of Radiation Medicine, Beijing 102206, China
- Key
Laboratory of Combinatorial Biosynthesis and Drug Discovery (Wuhan
University), Ministry of Education , and Wuhan University School of Pharmaceutical Sciences, Wuhan 430071, China
| | - Fengxu Fan
- State
Key Laboratory of Proteomics, Beijing Proteome Research Center, National
Engineering Research Center for Protein Drugs, National Center for
Protein Sciences, Beijing Institute of Radiation Medicine, Beijing 102206, China
- Anhui Medical University, Hefei 230032, Anhui China
| | - Mingzhi Zhao
- State
Key Laboratory of Proteomics, Beijing Proteome Research Center, National
Engineering Research Center for Protein Drugs, National Center for
Protein Sciences, Beijing Institute of Radiation Medicine, Beijing 102206, China
| | - Feilin Wu
- State
Key Laboratory of Proteomics, Beijing Proteome Research Center, National
Engineering Research Center for Protein Drugs, National Center for
Protein Sciences, Beijing Institute of Radiation Medicine, Beijing 102206, China
- Life
Science College, Southwest Forestry University, Kunming 650224, China
| | - Yuan Gao
- State
Key Laboratory of Proteomics, Beijing Proteome Research Center, National
Engineering Research Center for Protein Drugs, National Center for
Protein Sciences, Beijing Institute of Radiation Medicine, Beijing 102206, China
| | - Yanchang Li
- State
Key Laboratory of Proteomics, Beijing Proteome Research Center, National
Engineering Research Center for Protein Drugs, National Center for
Protein Sciences, Beijing Institute of Radiation Medicine, Beijing 102206, China
| | - Lingsheng Chen
- State
Key Laboratory of Proteomics, Beijing Proteome Research Center, National
Engineering Research Center for Protein Drugs, National Center for
Protein Sciences, Beijing Institute of Radiation Medicine, Beijing 102206, China
- State Key
Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning 530005, China
| | - Miaomiao Tian
- State
Key Laboratory of Proteomics, Beijing Proteome Research Center, National
Engineering Research Center for Protein Drugs, National Center for
Protein Sciences, Beijing Institute of Radiation Medicine, Beijing 102206, China
| | - Tao Zhang
- State
Key Laboratory of Proteomics, Beijing Proteome Research Center, National
Engineering Research Center for Protein Drugs, National Center for
Protein Sciences, Beijing Institute of Radiation Medicine, Beijing 102206, China
| | - Bo Wen
- BGI-Shenzhen, Shenzhen 518083, China
| | - Na Sensang
- Inner Mongolia Medical University, Hohhot 010110, Inner Mongolia China
| | - Zhi Xiong
- Life
Science College, Southwest Forestry University, Kunming 650224, China
| | - Songfeng Wu
- State
Key Laboratory of Proteomics, Beijing Proteome Research Center, National
Engineering Research Center for Protein Drugs, National Center for
Protein Sciences, Beijing Institute of Radiation Medicine, Beijing 102206, China
| | - Siqi Liu
- BGI-Shenzhen, Shenzhen 518083, China
| | - Pengyuan Yang
- Institute
of Biomedical Sciences, Department of Chemistry, and Zhongshan Hospital, Fudan University, 130 DongAn Road, Shanghai 200032, China
| | - Bei Zhen
- State
Key Laboratory of Proteomics, Beijing Proteome Research Center, National
Engineering Research Center for Protein Drugs, National Center for
Protein Sciences, Beijing Institute of Radiation Medicine, Beijing 102206, China
| | - Yunping Zhu
- State
Key Laboratory of Proteomics, Beijing Proteome Research Center, National
Engineering Research Center for Protein Drugs, National Center for
Protein Sciences, Beijing Institute of Radiation Medicine, Beijing 102206, China
| | - Fuchu He
- State
Key Laboratory of Proteomics, Beijing Proteome Research Center, National
Engineering Research Center for Protein Drugs, National Center for
Protein Sciences, Beijing Institute of Radiation Medicine, Beijing 102206, China
| | - Ping Xu
- State
Key Laboratory of Proteomics, Beijing Proteome Research Center, National
Engineering Research Center for Protein Drugs, National Center for
Protein Sciences, Beijing Institute of Radiation Medicine, Beijing 102206, China
- Key
Laboratory of Combinatorial Biosynthesis and Drug Discovery (Wuhan
University), Ministry of Education , and Wuhan University School of Pharmaceutical Sciences, Wuhan 430071, China
- Anhui Medical University, Hefei 230032, Anhui China
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5
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Low TY, Magliozzi R, Guardavaccaro D, Heck AJR. Unraveling the ubiquitin-regulated signaling networks by mass spectrometry-based proteomics. Proteomics 2012; 13:526-37. [PMID: 23019148 DOI: 10.1002/pmic.201200244] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Revised: 08/08/2012] [Accepted: 08/22/2012] [Indexed: 11/11/2022]
Abstract
Ubiquitin (Ub) is a small protein modifier that is covalently attached to the ε-amino group of lysine residues of protein substrates, generally targeting them for degradation. Due to the emergence of specific anti-diglycine (-GG) antibodies and the improvement in MS, it is now possible to identify more than 10 000 ubiquitylated sites in a single proteomics study. Besides cataloging ubiquitylated sites, it is equally important to unravel the biological relationship between ubiquitylated substrates and the ubiquitin conjugation machinery. Relevant to this, we discuss the role of affinity purification-MS (AP-MS), in characterizing E3 ligase-substrate complexes. Recently, such strategies have also been adapted to screen for binding partners of both deubiquitylating enzymes (DUBs) and ubiquitin-binding domains (UBDs). The complexity of the "ubiquitome" is further expanded by the fact that Ub itself can be ubiquitylated at any of its seven lysine residues forming polyubiquitin (polyUb), thus diversifying its lengths and topologies to suit a variety of molecular recognition processes. Therefore, applying MS to study polyUb linkages is also becoming an emerging and important area. Finally, we discuss the future of MS-based proteomics in answering important questions with respect to ubiquitylation.
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Affiliation(s)
- Teck Yew Low
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands.
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6
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Xu P, Tan H, Duong DM, Yang Y, Kupsco J, Moberg KH, Li H, Jin P, Peng J. Stable isotope labeling with amino acids in Drosophila for quantifying proteins and modifications. J Proteome Res 2012; 11:4403-12. [PMID: 22830426 DOI: 10.1021/pr300613c] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Drosophila melanogaster is a common animal model for genetics studies, and quantitative proteomics studies of the fly are emerging. Here, we present in detail the development of a procedure to incorporate stable isotope-labeled amino acids into the fly proteome. In the method of stable isotope labeling with amino acids in Drosophila melanogaster (SILAC fly), flies were fed with SILAC-labeled yeast grown with modified media, enabling near complete labeling in a single generation. Biological variation in the proteome among individual flies was evaluated in a series of null experiments. We further applied the SILAC fly method to profile proteins from a model of fragile X syndrome, the most common cause of inherited mental retardation in human. The analysis identified a number of altered proteins in the disease model, including actin-binding protein profilin and microtubulin-associated protein futsch. The change of both proteins was validated by immunoblotting analysis. Moreover, we extended the SILAC fly strategy to study the dynamics of protein ubiquitination during the fly life span (from day 1 to day 30), by measuring the level of ubiquitin along with two major polyubiquitin chains (K48 and K63 linkages). The results show that the abundance of protein ubiquitination and the two major linkages do not change significantly within the measured age range. Together, the data demonstrate the application of the SILAC principle in D. melanogaster, facilitating the integration of powerful fly genomics with emerging proteomics.
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Affiliation(s)
- Ping Xu
- Department of Human Genetics, Center for Neurodegenerative Diseases, Emory University School of Medicine, Atlanta, Georgia 30322, USA
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7
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Quantitative proteomics to decipher ubiquitin signaling. Amino Acids 2012; 43:1049-60. [PMID: 22821265 DOI: 10.1007/s00726-012-1286-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Accepted: 04/03/2012] [Indexed: 12/21/2022]
Abstract
Ubiquitin signaling plays an essential role in controlling cellular processes in eukaryotes, and the impairment of ubiquitin regulation contributes to the pathogenesis of a wide range of human diseases. During the last decade, mass spectrometry-based proteomics has emerged as an indispensable approach for identifying the ubiquitinated proteome (ubiquitinome), ubiquitin modification sites, the linkages of complex ubiquitin chains, as well as the interactome of ubiquitin enzymes. In particular, implementation of quantitative strategies allows the detection of dynamic changes in the ubiquitinome, enhancing the ability to differentiate between function-relevant protein targets and false positives arising from biological and experimental variations. The profiling of total cell lysate and the ubiquitinated proteome in the same sets of samples has become a powerful tool, revealing a subset of substrates that are modulated by specific physiological and pathological conditions, such as gene mutations in ubiquitin signaling. This strategy is equally useful for dissecting the pathways of ubiquitin-like proteins.
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8
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Bustos D, Bakalarski CE, Yang Y, Peng J, Kirkpatrick DS. Characterizing ubiquitination sites by peptide-based immunoaffinity enrichment. Mol Cell Proteomics 2012; 11:1529-40. [PMID: 22729469 DOI: 10.1074/mcp.r112.019117] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Advances in high resolution tandem mass spectrometry and peptide enrichment technologies have transformed the field of protein biochemistry by enabling analysis of end points that have traditionally been inaccessible to molecular and biochemical techniques. One field benefitting from this research has been the study of ubiquitin, a 76-amino acid protein that functions as a covalent modifier of other proteins. Seminal work performed decades ago revealed that trypsin digestion of a branched protein structure known as A24 yielded an enigmatic diglycine signature bound to a lysine residue in histone 2A. With the onset of mass spectrometry proteomics, identification of K-GG-modified peptides has emerged as an effective way to map the position of ubiquitin modifications on a protein of interest and to quantify the extent of substrate ubiquitination. The initial identification of K-GG peptides by mass spectrometry initiated a flurry of work aimed at enriching these post-translationally modified peptides for identification and quantification en masse. Recently, immunoaffinity reagents have been reported that are capable of capturing K-GG peptides from ubiquitin and its thousands of cellular substrates. Here we focus on the history of K-GG peptides, their identification by mass spectrometry, and the utility of immunoaffinity reagents for studying the mechanisms of cellular regulation by ubiquitin.
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Affiliation(s)
- Daisy Bustos
- Department of Protein Chemistry, Genentech, Inc., South San Francisco, California 94080, USA
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9
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Abstract
Protein modification by ubiquitin (Ub) is one of the most common posttranslational events in eukaryotic cells. Ubiquitinated proteins are destined to various fates such as proteasomal degradation, protein trafficking, DNA repair, and immune response. In the last decade, vast improvements of mass spectrometry make it feasible to analyze the minute amount of ubiquitinated components in vivo. When combined with quantitative strategies, such as stable isotope labeling with amino acids in cell culture (SILAC), it is capable of profiling ubiquitinated proteome under different experimental conditions. Here, we describe a procedure to perform such a study, including differential protein labeling by the SILAC method, enrichment of ubiquitinated species, mass spectrometric analysis, and quality control to reduce false positives. The potential challenges and limitations of the procedure are also discussed.
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Affiliation(s)
- Chan Hyun Na
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
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10
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Abstract
Protein ubiquitylation is a highly conserved, central mechanism to regulate cellular events in all eukaryotes, such as proteasomal degradation, protein trafficking, DNA repair, synaptic plasticity, and immune response. The consequence of protein ubiquitylation is modulated by the structure of ubiquitin (Ub) moiety attached on the substrates, including ubiquitin monomer and diverse polyubiquitin chains with different linkages (N-terminus, K6, K11, K27, K29, K33, K48, and K63). The development of ubiquitin-enrichment strategies coupled with sensitive mass spectrometry enables direct analysis of ubiquitylated proteins in cells, providing an invaluable tool for ubiquitin research. In this chapter, we describe recent technology updates for analyzing tissue-specific ubiquitin conjugates in transgenic models, as well as targeted proteomics methods for quantifying different polyubiquitin chain linkages in any type of -samples, including human tissues.
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11
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Dammer EB, Na CH, Xu P, Seyfried NT, Duong DM, Cheng D, Gearing M, Rees H, Lah JJ, Levey AI, Rush J, Peng J. Polyubiquitin linkage profiles in three models of proteolytic stress suggest the etiology of Alzheimer disease. J Biol Chem 2011; 286:10457-65. [PMID: 21278249 DOI: 10.1074/jbc.m110.149633] [Citation(s) in RCA: 135] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Polyubiquitin chains on substrates are assembled through any of seven lysine residues or the N terminus of ubiquitin (Ub), generating diverse linkages in the chain structure. PolyUb linkages regulate the fate of modified substrates, but their abundance and function in mammalian cells are not well studied. We present a mass spectrometry-based method to measure polyUb linkages directly from total lysate of mammalian cells. In HEK293 cells, the level of polyUb linkages was found to be 52% (Lys(48)), 38% (Lys(63)), 8% (Lys(29)), 2% (Lys(11)), and 0.5% or less for linear, Lys(6), Lys(27), and Lys(33) linkages. Tissue specificity of these linkages was examined in mice fully labeled by heavy stable isotopes (i.e. SILAC mice). Moreover, we profiled the Ub linkages in brain tissues from patients of Alzheimer disease with or without concurrent Lewy body disease as well as three cellular models of proteolytic stress: proteasome deficiency, lysosome deficiency, and heat shock. The data support that polyUb chains linked through Lys(6), Lys(11), Lys(27), Lys(29), and Lys(48) mediate proteasomal degradation, whereas Lys(63) chains are preferentially involved in the lysosomal pathway. Mixed linkages, including Lys(48), may also contribute to lysosomal targeting, as both Lys(63) and Lys(48) linkages are colocalized in LC3-labeled autophagosomes. Interestingly, heat shock treatment augments Lys(11), Lys(48), and Lys(63) but not Lys(29) linkages, and this unique pattern is similar to that in the profiled neurodegenerative cases. We conclude that different polyUb linkages play distinct roles under the three proteolytic stress conditions, and protein folding capacity in the heat shock responsive pathway might be more affected in Alzheimer disease.
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Affiliation(s)
- Eric B Dammer
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia 30322, USA
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12
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Riley BE, Kaiser SE, Shaler TA, Ng ACY, Hara T, Hipp MS, Lage K, Xavier RJ, Ryu KY, Taguchi K, Yamamoto M, Tanaka K, Mizushima N, Komatsu M, Kopito RR. Ubiquitin accumulation in autophagy-deficient mice is dependent on the Nrf2-mediated stress response pathway: a potential role for protein aggregation in autophagic substrate selection. ACTA ACUST UNITED AC 2010; 191:537-52. [PMID: 21041446 PMCID: PMC3003313 DOI: 10.1083/jcb.201005012] [Citation(s) in RCA: 136] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Inactivation of the essential autophagy gene Atg5 results in selective accumulation of aggregation-prone proteins independently of substrate ubiquitination. Genetic ablation of autophagy in mice leads to liver and brain degeneration accompanied by the appearance of ubiquitin (Ub) inclusions, which has been considered to support the hypothesis that ubiquitination serves as a cis-acting signal for selective autophagy. We show that tissue-specific disruption of the essential autophagy genes Atg5 and Atg7 leads to the accumulation of all detectable Ub–Ub topologies, arguing against the hypothesis that any particular Ub linkage serves as a specific autophagy signal. The increase in Ub conjugates in Atg7−/− liver and brain is completely suppressed by simultaneous knockout of either p62 or Nrf2. We exploit a novel assay for selective autophagy in cell culture, which shows that inactivation of Atg5 leads to the selective accumulation of aggregation-prone proteins, and this does not correlate with an increase in substrate ubiquitination. We propose that protein oligomerization drives autophagic substrate selection and that the accumulation of poly-Ub chains in autophagy-deficient circumstances is an indirect consequence of activation of Nrf2-dependent stress response pathways.
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Affiliation(s)
- Brigit E Riley
- Department of Biology, Stanford University, Stanford, CA 94305, USA.
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Quantitative proteomics reveals the function of unconventional ubiquitin chains in proteasomal degradation. Cell 2009; 137:133-45. [PMID: 19345192 DOI: 10.1016/j.cell.2009.01.041] [Citation(s) in RCA: 861] [Impact Index Per Article: 57.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2008] [Revised: 11/07/2008] [Accepted: 01/20/2009] [Indexed: 12/19/2022]
Abstract
All seven lysine residues in ubiquitin contribute to the synthesis of polyubiquitin chains on protein substrates. Whereas K48-linked chains are well established as mediators of proteasomal degradation, and K63-linked chains act in nonproteolytic events, the roles of unconventional polyubiquitin chains linked through K6, K11, K27, K29, or K33 are not well understood. Here, we report that the unconventional linkages are abundant in vivo and that all non-K63 linkages may target proteins for degradation. Ubiquitin with K48 as the single lysine cannot support yeast viability, and different linkages have partially redundant functions. By profiling both the entire yeast proteome and ubiquitinated proteins in wild-type and ubiquitin K11R mutant strains using mass spectrometry, we identified K11 linkage-specific substrates, including Ubc6, a ubiquitin-conjugating enzyme involved in endoplasmic reticulum-associated degradation (ERAD). Ubc6 primarily synthesizes K11-linked chains, and K11 linkages function in the ERAD pathway. Thus, unconventional polyubiquitin chains are critical for ubiquitin-proteasome system function.
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Matiuhin Y, Kirkpatrick DS, Ziv I, Kim W, Dakshinamurthy A, Kleifeld O, Gygi SP, Reis N, Glickman MH. Extraproteasomal Rpn10 restricts access of the polyubiquitin-binding protein Dsk2 to proteasome. Mol Cell 2008; 32:415-25. [PMID: 18995839 PMCID: PMC2643056 DOI: 10.1016/j.molcel.2008.10.011] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2007] [Revised: 06/01/2008] [Accepted: 10/10/2008] [Indexed: 10/21/2022]
Abstract
Polyubiquitin is a diverse signal both in terms of chain length and linkage type. Lysine 48-linked ubiquitin is essential for marking targets for proteasomal degradation, but the significance and relative abundance of different linkages remain ambiguous. Here we dissect the relationship of two proteasome-associated polyubiquitin-binding proteins, Rpn10 and Dsk2, and demonstrate how Rpn10 filters Dsk2 interactions, maintaining proper function of the ubiquitin-proteasome system. Using quantitative mass spectrometry of ubiquitin, we found that in S. cerevisiae under normal growth conditions the majority of conjugated ubiquitin was linked via lysine 48 and lysine 63. In contrast, upon DSK2 induction, conjugates accumulated primarily in the form of lysine 48 linkages correlating with impaired proteolysis and cytotoxicity. By restricting Dsk2 access to the proteasome, extraproteasomal Rpn10 was essential for alleviating the cellular stress associated with Dsk2. This work highlights the importance of polyubiquitin shuttles such as Rpn10 and Dsk2 in controlling the ubiquitin landscape.
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Affiliation(s)
- Yulia Matiuhin
- Department of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel
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15
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Meierhofer D, Wang X, Huang L, Kaiser P. Quantitative analysis of global ubiquitination in HeLa cells by mass spectrometry. J Proteome Res 2008; 7:4566-76. [PMID: 18781797 DOI: 10.1021/pr800468j] [Citation(s) in RCA: 155] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Ubiquitination regulates a host of cellular processes by labeling proteins for degradation, but also by functioning as a regulatory, nonproteolytic posttranslational modification. Proteome-wide strategies to monitor changes in ubiquitination profiles are important to obtain insight into the various cellular functions of ubiquitination. Here we describe generation of stable cell lines expressing a tandem hexahistidine-biotin tag (HB-tag) fused to ubiquitin for two-step purification of the ubiquitinated proteome under fully denaturing conditions. Using this approach we identified 669 ubiquitinated proteins from HeLa cells, including 44 precise ubiquitin attachment sites on substrates and all seven possible ubiquitin chain-linkage types. To probe the dynamics of ubiquitination in response to perturbation of the ubiquitin/proteasome pathway, we combined ubiquitin profiling with quantitative mass spectrometry using the stable isotope labeling with amino acids in cell culture (SILAC) strategy. We compared untreated cells and cells treated with the proteasome inhibitor MG132 to identify ubiquitinated proteins that are targeted to the proteasome for degradation. A number of proteasome substrates were identified. In addition, the quantitative approach allowed us to compare proteasome targeting by different ubiquitin chain topologies in vivo. The tools and strategies described here can be applied to detect changes in ubiquitination dynamics in response to various changes in growth conditions and cellular stress and will contribute to our understanding of the ubiquitin/proteasome system.
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Affiliation(s)
- David Meierhofer
- Department of Biological Chemistry, University of California, Irvine, California 92697, USA
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16
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Winborn BJ, Travis SM, Todi SV, Scaglione KM, Xu P, Williams AJ, Cohen RE, Peng J, Paulson HL. The deubiquitinating enzyme ataxin-3, a polyglutamine disease protein, edits Lys63 linkages in mixed linkage ubiquitin chains. J Biol Chem 2008; 283:26436-43. [PMID: 18599482 DOI: 10.1074/jbc.m803692200] [Citation(s) in RCA: 207] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ubiquitin chain complexity in cells is likely regulated by a diverse set of deubiquitinating enzymes (DUBs) with distinct ubiquitin chain preferences. Here we show that the polyglutamine disease protein, ataxin-3, binds and cleaves ubiquitin chains in a manner suggesting that it functions as a mixed linkage, chain-editing enzyme. Ataxin-3 cleaves ubiquitin chains through its amino-terminal Josephin domain and binds ubiquitin chains through a carboxyl-terminal cluster of ubiquitin interaction motifs neighboring the pathogenic polyglutamine tract. Ataxin-3 binds both Lys(48)- or Lys(63)-linked chains yet preferentially cleaves Lys(63) linkages. Ataxin-3 shows even greater activity toward mixed linkage polyubiquitin, cleaving Lys(63) linkages in chains that contain both Lys(48) and Lys(63) linkages. The ubiquitin interaction motifs regulate the specificity of this activity by restricting what can be cleaved by the protease domain, demonstrating that linkage specificity can be determined by elements outside the catalytic domain of a DUB. These findings establish ataxin-3 as a novel DUB that edits topologically complex chains.
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Affiliation(s)
- Brett J Winborn
- Department of Neurology, University of Michigan, Ann Arbor, Michigan 48108, USA
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17
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Seyfried NT, Xu P, Duong DM, Cheng D, Hanfelt J, Peng J. Systematic approach for validating the ubiquitinated proteome. Anal Chem 2008; 80:4161-9. [PMID: 18433149 DOI: 10.1021/ac702516a] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Protein ubiquitination plays an essential regulatory role within all eukaryotes. Large-scale analyses of ubiquitinated proteins are usually performed by combining affinity purification strategies with mass spectrometry. However, there is no reliable method to systematically differentiate ubiquitinated species from copurified unmodified components. Here we report a simple strategy for the large-scale validation of ubiquitination by reconstructing virtual Western blots for proteins analyzed by gel electrophoresis and mass spectrometry. Because protein ubiquitination, especially polyubiquitination, causes a dramatic shift of molecular weight, the difference between experimental and expected molecular weight was used to confirm the status of ubiquitination. Experimental molecular weight of putative yeast ubiquitin-conjugates was computed from the value and distribution of spectral counts in the gel using a Gaussian curve fitting approach. Unmodified proteins in yeast cell lysate were also analyzed as a control to assess the accuracy of the method. Multiple thresholds that incorporated the mass of ubiquitin and/or experimental variations were evaluated with respect to sensitivity and specificity. Ultimately, only approximately 30% of the candidate ubiquitin-conjugates were accepted based on the stringent filtering criteria, although they were purified under denaturing conditions. These accepted conjugates had an estimated false discovery rate of approximately 8% and primarily consisted of proteins larger than 100 kDa. Compared with another validation method (i.e., identification of ubiquitinated lysine sites), approximately 95% of the proteins with defined modification sites showed a convincing increase in molecular weight on the virtual Western blots. A second independent analysis indicated that the method can be simplified by excising fewer than ten gel bands. Therefore, this strategy establishes criteria necessary for the interpretation of ubiquitinated proteins.
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Affiliation(s)
- Nicholas T Seyfried
- Department of Human Genetics, Center for Neurodegenerative Diseases, Emory University, Atlanta, Georgia 30322, USA
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19
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Xu P, Peng J. Dissecting the ubiquitin pathway by mass spectrometry. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2006; 1764:1940-7. [PMID: 17055348 PMCID: PMC1828906 DOI: 10.1016/j.bbapap.2006.09.004] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2006] [Revised: 08/30/2006] [Accepted: 09/06/2006] [Indexed: 11/27/2022]
Abstract
Protein modification by ubiquitin is a central regulatory mechanism in eukaryotic cells. Recent proteomics developments in mass spectrometry enable systematic analysis of cellular components in the ubiquitin pathway. Here, we review the advances in analyzing ubiquitinated substrates, determining modified lysine residues, quantifying polyubiquitin chain topologies, as well as profiling deubiquitinating enzymes based on the activity. Moreover, proteomic approaches have been developed for probing the interactome of proteasome and for identifying proteins with ubiquitin-binding domains. Similar strategies have been applied on the studies of the modification by ubiquitin-like proteins as well. These strategies are discussed with respect to their advantages, limitations and potential improvements. While the utilization of current methodologies has rapidly expanded the scope of protein modification by the ubiquitin family, a more active role is anticipated in the functional studies with the emergence of quantitative mass spectrometry.
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Affiliation(s)
- Ping Xu
- Department of Human Genetics, Center for Neurodegenerative Disease, Emory University, Atlanta, GA 30322
| | - Junmin Peng
- Department of Human Genetics, Center for Neurodegenerative Disease, Emory University, Atlanta, GA 30322
- Address correspondence to Junmin Peng, E-mail:
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