1
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Shiomi Y, Hayashi A, Saito Y, Kanemaki MT, Nishitani H. The Depletion of TRAIP Results in the Retention of PCNA on Chromatin During Mitosis Leads to Inhibiting DNA Replication Initiation. Genes Cells 2025; 30:e70006. [PMID: 39956965 DOI: 10.1111/gtc.70006] [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] [Received: 05/07/2024] [Revised: 01/17/2025] [Accepted: 01/29/2025] [Indexed: 02/18/2025]
Abstract
Loading PCNA onto chromatin is a pivotal step in DNA replication, cell cycle progression, and genome integrity. Conversely, unloading PCNA from chromatin is equally crucial for maintaining genome stability. Cells deficient in the PCNA unloader ATAD5-RFC exhibit elevated levels of chromatin-bound PCNA during S phase, but still show dissociation of PCNA from chromatin in mitosis. In this study, we found that depletion of TRAIP, an E3 ubiquitin ligase, results in the retention of PCNA on chromatin during mitosis. Although TRAIP-depleted cells with chromatin-bound PCNA during mitosis progressed into the subsequent G1 phase, they displayed reduced levels of Cdt1, a key replication licensing factor, and impaired S phase entry. In addition, TRAIP-depleted cells exhibited delayed S phase progression. These results suggest that TRAIP functions independently of ATAD5-RFC in removing PCNA from chromatin. Furthermore, TRAIP appears to be essential for precise pre-replication complexes (pre-RCs) formation necessary for faithful initiation of DNA replication and S phase progression.
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Affiliation(s)
- Yasushi Shiomi
- Graduate School of Science, University of Hyogo, Kamigori, Japan
| | - Akiyo Hayashi
- Graduate School of Science, University of Hyogo, Kamigori, Japan
| | - Yuichiro Saito
- Department of Chromosome Science, National Institute of Genetics, Research Organization of Information and Systems (ROIS), Shizuoka, Japan
| | - Masato T Kanemaki
- Department of Chromosome Science, National Institute of Genetics, Research Organization of Information and Systems (ROIS), Shizuoka, Japan
- Department of Advanced Studies, The Graduate University for Advanced Studies (SOKENDAI), Shizuoka, Japan
- Department of Biological Science, The University of Tokyo, Tokyo, Japan
| | - Hideo Nishitani
- Graduate School of Science, University of Hyogo, Kamigori, Japan
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2
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Zhang R, Liu B, Tian Y, Xin M, Li Q, Huang X, Liu Y, Zhao L, Qi F, Wang R, Meng X, Chen J, Zhou J, Gao J. A chromosome-coupled ubiquitin-proteasome pathway is required for meiotic surveillance. Cell Death Differ 2024; 31:1730-1745. [PMID: 39237708 PMCID: PMC11618355 DOI: 10.1038/s41418-024-01375-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 08/29/2024] [Accepted: 09/02/2024] [Indexed: 09/07/2024] Open
Abstract
Defects in meiotic prophase can cause meiotic chromosome missegregation and aneuploid gamete formation. Meiotic checkpoints are activated in germ cells with meiotic defects, and cells with unfixed errors are eliminated by apoptosis. How such a surveillance process is regulated remains elusive. Here, we report that a chromosome-coupled ubiquitin-proteasome pathway (UPP) regulates meiotic checkpoint activation and promotes germ cell apoptosis in C. elegans meiosis-defective mutants. We identified an F-box protein, FBXL-2, that functions as a core component within the pathway. This chromosome-coupled UPP regulates meiotic DSB repair kinetics and chromosome dynamic behaviors in synapsis defective mutants. Disrupted UPP impairs the axial recruitment of the HORMA domain protein HIM-3, which is required for efficient germ cell apoptosis in synapsis defective mutants. Our data suggest that an efficient chromosome-coupled UPP functions as a part of the meiotic surveillance system by enhancing the integrity of the meiotic chromosome axis.
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Affiliation(s)
- Ruirui Zhang
- Center for Cell Structure and Function, College of Life Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, 250358, China
| | - Bohan Liu
- Center for Cell Structure and Function, College of Life Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, 250358, China
| | - Yuqi Tian
- Center for Cell Structure and Function, College of Life Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, 250358, China
| | - Mingyu Xin
- Center for Cell Structure and Function, College of Life Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, 250358, China
| | - Qian Li
- State Key Laboratory of Medicinal Chemical Biology, Haihe Laboratory of Cell Ecosystem, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Xiuhua Huang
- Center for Cell Structure and Function, College of Life Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, 250358, China
| | - Yuanyuan Liu
- Center for Cell Structure and Function, College of Life Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, 250358, China
| | - Li Zhao
- Center for Cell Structure and Function, College of Life Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, 250358, China
| | - Feifei Qi
- Center for Cell Structure and Function, College of Life Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, 250358, China
| | - Ruoxi Wang
- Center for Cell Structure and Function, College of Life Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, 250358, China
| | - Xiaoqian Meng
- Center for Cell Structure and Function, College of Life Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, 250358, China
| | - Jianguo Chen
- Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, College of Life Sciences, Peking University, Beijing, 100871, China
- Center for Quantitative Biology, Peking University, Beijing, 100871, China
| | - Jun Zhou
- Center for Cell Structure and Function, College of Life Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, 250358, China
- State Key Laboratory of Medicinal Chemical Biology, Haihe Laboratory of Cell Ecosystem, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Jinmin Gao
- Center for Cell Structure and Function, College of Life Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, 250358, China.
- State Key Laboratory of Medicinal Chemical Biology, Haihe Laboratory of Cell Ecosystem, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, 300071, China.
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3
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Jeanne F, Bernay B, Sourdaine P. Comparative Proteome Analysis of Four Stages of Spermatogenesis in the Small-Spotted Catshark ( Scyliorhinus canicula), Using High-Resolution NanoLC-ESI-MS/MS. J Proteome Res 2023. [PMID: 37290099 DOI: 10.1021/acs.jproteome.3c00206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Spermatogenesis is a highly specialized process of cell proliferation and differentiation leading to the production of spermatozoa from spermatogonial stem cells. Due to its testicular anatomy, Scyliorhinus canicula is an interesting model to explore stage-based changes in proteins during spermatogenesis. The proteomes of four testicular zones corresponding to the germinative niche and to spermatocysts (cysts) with spermatogonia (zone A), cysts with spermatocytes (zone B), cysts with young spermatids (zone C), and cysts with late spermatids (zone D) have been analyzed by nanoLC-ESI-MS/MS. Gene ontology and KEGG annotations were also performed. A total of 3346 multiple protein groups were identified. Zone-specific protein analyses highlighted RNA-processing, chromosome-related processes, cilium organization, and cilium activity in zones A, D, C, and D, respectively. Analyses of proteins with zone-dependent abundance revealed processes related to cellular stress, ubiquitin-dependent degradation by the proteasome, post-transcriptional regulation, and regulation of cellular homeostasis. Our results also suggest that the roles of some proteins, such as ceruloplasmin, optineurin, the pregnancy zone protein, PA28β or the Culling-RING ligase 5 complex, as well as some uncharacterized proteins, during spermatogenesis could be further explored. Finally, the study of this shark species allows one to integrate these data in an evolutionary context of the regulation of spermatogenesis. Mass spectrometry data are freely accessible via iProX-integrated Proteome resources (https://www.iprox.cn/) for reuse purposes.
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Affiliation(s)
- Fabian Jeanne
- Université de Caen Normandie, MNHN, SU, UA, CNRS, IRD, Laboratoire de Biologie des Organismes et Ecosystèmes Aquatiques (BOREA), UMR 8067, 14032 Caen cedex 5, France
| | - Benoît Bernay
- Université de Caen Normandie - Plateforme PROTEOGEN, US EMerode, 14032 Caen cedex 5, France
| | - Pascal Sourdaine
- Université de Caen Normandie, MNHN, SU, UA, CNRS, IRD, Laboratoire de Biologie des Organismes et Ecosystèmes Aquatiques (BOREA), UMR 8067, 14032 Caen cedex 5, France
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4
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Martínez-Fernández C, Jha S, Aliagas E, Holmberg CI, Nadal E, Cerón J. BAP1 Malignant Pleural Mesothelioma Mutations in Caenorhabditis elegans Reveal Synthetic Lethality between ubh-4/ BAP1 and the Proteasome Subunit rpn-9/ PSMD13. Cells 2023; 12:929. [PMID: 36980270 PMCID: PMC10047281 DOI: 10.3390/cells12060929] [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] [Received: 01/16/2023] [Revised: 02/28/2023] [Accepted: 03/02/2023] [Indexed: 03/30/2023] Open
Abstract
The deubiquitinase BAP1 (BRCA1-associated protein 1) is associated with BAP1 tumor predisposition syndrome (TPDS). BAP1 is a tumor suppressor gene whose alterations in cancer are commonly caused by gene mutations leading to protein loss of function. By CRISPR-Cas, we have generated mutations in ubh-4, the BAP1 ortholog in Caenorhabditis elegans, to model the functional impact of BAP1 mutations. We have found that a mimicked BAP1 cancer missense mutation (UBH-4 A87D; BAP1 A95D) resembles the phenotypes of ubh-4 deletion mutants. Despite ubh-4 being ubiquitously expressed, the gene is not essential for viability and its deletion causes only mild phenotypes without affecting 20S proteasome levels. Such viability facilitated an RNAi screen for ubh-4 genetic interactors that identified rpn-9, the ortholog of human PSMD13, a gene encoding subunit of the regulatory particle of the 26S proteasome. ubh-4[A87D], similarly to ubh-4 deletion, cause a synthetic genetic interaction with rpn-9 inactivation affecting body size, lifespan, and the development of germ cells. Finally, we show how ubh-4 inactivation sensitizes animals to the chemotherapeutic agent Bortezomib, which is a proteasome inhibitor. Thus, we have established a model to study BAP1 cancer-related mutations in C. elegans, and our data points toward vulnerabilities that should be studied to explore therapeutic opportunities within the complexity of BAP1 tumors.
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Affiliation(s)
- Carmen Martínez-Fernández
- Modeling Human Diseases in C. elegans Group, Genes, Diseases, and Therapies Program, Institut d’Investigació Biomèdica de Bellvitge (IDIBELL), L’Hospitalet de Llobregat, 08908 Barcelona, Spain
| | - Sweta Jha
- Medicum, Department of Biochemistry and Developmental Biology, Faculty of Medicine, University of Helsinki, Haartmaninkatu 8, 00290 Helsinki, Finland
| | - Elisabet Aliagas
- Department of Medical Oncology, Institut Català d’Oncologia (ICO), L’Hospitalet de Llobregat, 08908 Barcelona, Spain
| | - Carina I. Holmberg
- Medicum, Department of Biochemistry and Developmental Biology, Faculty of Medicine, University of Helsinki, Haartmaninkatu 8, 00290 Helsinki, Finland
| | - Ernest Nadal
- Department of Medical Oncology, Institut Català d’Oncologia (ICO), L’Hospitalet de Llobregat, 08908 Barcelona, Spain
- Preclinical and Experimental Research in Thoracic Tumors (PReTT), Institut d’Investigació Biomèdica de Bellvitge (IDIBELL), L’Hospitalet de Llobregat, 08908 Barcelona, Spain
| | - Julián Cerón
- Modeling Human Diseases in C. elegans Group, Genes, Diseases, and Therapies Program, Institut d’Investigació Biomèdica de Bellvitge (IDIBELL), L’Hospitalet de Llobregat, 08908 Barcelona, Spain
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5
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Fernando LM, Quesada-Candela C, Murray M, Ugoaru C, Yanowitz JL, Allen AK. Proteasomal subunit depletions differentially affect germline integrity in C. elegans. Front Cell Dev Biol 2022; 10:901320. [PMID: 36060813 PMCID: PMC9428126 DOI: 10.3389/fcell.2022.901320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 07/08/2022] [Indexed: 11/25/2022] Open
Abstract
The 26S proteasome is a multi-subunit protein complex that is canonically known for its ability to degrade proteins in cells and maintain protein homeostasis. Non-canonical or non-proteolytic roles of proteasomal subunits exist but remain less well studied. We provide characterization of germline-specific functions of different 19S proteasome regulatory particle (RP) subunits in C. elegans using RNAi specifically from the L4 stage and through generation of endogenously tagged 19S RP lid subunit strains. We show functions for the 19S RP in regulation of proliferation and maintenance of integrity of mitotic zone nuclei, in polymerization of the synaptonemal complex (SC) onto meiotic chromosomes and in the timing of SC subunit redistribution to the short arm of the bivalent, and in turnover of XND-1 proteins at late pachytene. Furthermore, we report that certain 19S RP subunits are required for proper germ line localization of WEE-1.3, a major meiotic kinase. Additionally, endogenous fluorescent labeling revealed that the two isoforms of the essential 19S RP proteasome subunit RPN-6.1 are expressed in a tissue-specific manner in the hermaphrodite. Also, we demonstrate that the 19S RP subunits RPN-6.1 and RPN-7 are crucial for the nuclear localization of the lid subunits RPN-8 and RPN-9 in oocytes, further supporting the ability to utilize the C. elegans germ line as a model to study proteasome assembly real-time. Collectively, our data support the premise that certain 19S RP proteasome subunits are playing tissue-specific roles, especially in the germ line. We propose C. elegans as a versatile multicellular model to study the diverse proteolytic and non-proteolytic roles that proteasome subunits play in vivo.
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Affiliation(s)
| | - Cristina Quesada-Candela
- Magee-Womens Research Institute and Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Makaelah Murray
- Department of Biology, Howard University, Washington, DC, United States
| | - Caroline Ugoaru
- Department of Biology, Howard University, Washington, DC, United States
| | - Judith L. Yanowitz
- Magee-Womens Research Institute and Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
- Departments of Developmental Biology, Microbiology, and Molecular Genetics, The Hillman Cancer Center, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
- *Correspondence: Judith L. Yanowitz, ; Anna K. Allen,
| | - Anna K. Allen
- Department of Biology, Howard University, Washington, DC, United States
- *Correspondence: Judith L. Yanowitz, ; Anna K. Allen,
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6
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Tarcan Z, Poovathumkadavil D, Skagia A, Gambus A. The p97 segregase cofactor Ubxn7 facilitates replisome disassembly during S-phase. J Biol Chem 2022; 298:102234. [PMID: 35798141 PMCID: PMC9358472 DOI: 10.1016/j.jbc.2022.102234] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 06/22/2022] [Accepted: 06/23/2022] [Indexed: 11/20/2022] Open
Abstract
Complex cellular processes are driven by the regulated assembly and disassembly of large multiprotein complexes. While we are beginning to understand the molecular mechanism for assembly of the eukaryotic DNA replication machinery (replisome), we still know relatively little about the regulation of its disassembly at replication termination. Recently, the first elements of this process have emerged, revealing that the replicative helicase, at the heart of the replisome, is polyubiquitylated prior to unloading and that this unloading requires p97 segregase activity. Two different E3 ubiquitin ligases have now been shown to ubiquitylate the helicase under different conditions: Cul2Lrr1 and TRAIP. Here, using Xenopus laevis egg extract cell-free system and biochemical approaches, we have found two p97 cofactors, Ubxn7 and Faf1, which can interact with p97 during replisome disassembly during S-phase. We show only Ubxn7, however, facilitates efficient replisome disassembly. Ubxn7 delivers this role through its interaction via independent domains with both Cul2Lrr1 and p97 to allow coupling between Mcm7 ubiquitylation and its removal from chromatin. Our data therefore characterize Ubxn7 as the first substrate-specific p97 cofactor regulating replisome disassembly in vertebrates and a rationale for the efficacy of the Cul2Lrr1 replisome unloading pathway in unperturbed S-phase.
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7
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Xiong Y, Yu C, Zhang Q. Ubiquitin-Proteasome System-Regulated Protein Degradation in Spermatogenesis. Cells 2022; 11:1058. [PMID: 35326509 PMCID: PMC8947704 DOI: 10.3390/cells11061058] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 03/14/2022] [Accepted: 03/18/2022] [Indexed: 12/12/2022] Open
Abstract
Spermatogenesis is a prolonged and highly ordered physiological process that produces haploid male germ cells through more than 40 steps and experiences dramatic morphological and cellular transformations. The ubiquitin proteasome system (UPS) plays central roles in the precise control of protein homeostasis to ensure the effectiveness of certain protein groups at a given stage and the inactivation of them after this stage. Many UPS components have been demonstrated to regulate the progression of spermatogenesis at different levels. Especially in recent years, novel testis-specific proteasome isoforms have been identified to be essential and unique for spermatogenesis. In this review, we set out to discuss our current knowledge in functions of diverse USP components in mammalian spermatogenesis through: (1) the composition of proteasome isoforms at each stage of spermatogenesis; (2) the specificity of each proteasome isoform and the associated degradation events; (3) the E3 ubiquitin ligases mediating protein ubiquitination in male germ cells; and (4) the deubiquitinases involved in spermatogenesis and male fertility. Exploring the functions of UPS machineries in spermatogenesis provides a global picture of the proteome dynamics during male germ cell production and shed light on the etiology and pathogenesis of human male infertility.
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Affiliation(s)
- Yi Xiong
- Zhejiang University-University of Edinburgh Institute (ZJU-UoE Institute), Zhejiang University School of Medicine, International Campus, Zhejiang University, 718 East Haizhou Rd, Haining 314400, China;
| | - Chao Yu
- Key Laboratory of Reproductive Dysfunction Management of Zhejiang Province, Assisted Reproduction Unit, Department of Obstetrics and Gynecology, School of Medicine, Zhejiang University, Sir Run Run Shaw Hospital, 3 East Qing Chun Rd, Hangzhou 310020, China;
- College of Life Sciences, Zhejiang University, 866 Yuhangtang Rd, Hangzhou 310058, China
| | - Qianting Zhang
- Zhejiang University-University of Edinburgh Institute (ZJU-UoE Institute), Zhejiang University School of Medicine, International Campus, Zhejiang University, 718 East Haizhou Rd, Haining 314400, China;
- Department of Dermatology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang University, Hangzhou 310029, China
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8
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Zhang FG, Zhang RR, Gao JM. The organization, regulation, and biological functions of the synaptonemal complex. Asian J Androl 2021; 23:580-589. [PMID: 34528517 PMCID: PMC8577265 DOI: 10.4103/aja202153] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The synaptonemal complex (SC) is a meiosis-specific proteinaceous macromolecular structure that assembles between paired homologous chromosomes during meiosis in various eukaryotes. The SC has a highly conserved ultrastructure and plays critical roles in controlling multiple steps in meiotic recombination and crossover formation, ensuring accurate meiotic chromosome segregation. Recent studies in different organisms, facilitated by advances in super-resolution microscopy, have provided insights into the macromolecular structure of the SC, including the internal organization of the meiotic chromosome axis and SC central region, the regulatory pathways that control SC assembly and dynamics, and the biological functions exerted by the SC and its substructures. This review summarizes recent discoveries about how the SC is organized and regulated that help to explain the biological functions associated with this meiosis-specific structure.
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Affiliation(s)
- Feng-Guo Zhang
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan 250014, China
| | - Rui-Rui Zhang
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan 250014, China
| | - Jin-Min Gao
- Institute of Biomedical Sciences, College of Life Sciences, Key Laboratory of Animal Resistance Biology of Shandong Province, Shandong Normal University, Jinan 250014, China
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9
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Fan Y, Köberlin MS, Ratnayeke N, Liu C, Deshpande M, Gerhardt J, Meyer T. LRR1-mediated replisome disassembly promotes DNA replication by recycling replisome components. J Cell Biol 2021; 220:212186. [PMID: 34037657 PMCID: PMC8160578 DOI: 10.1083/jcb.202009147] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 03/30/2021] [Accepted: 05/04/2021] [Indexed: 11/22/2022] Open
Abstract
After two converging DNA replication forks meet, active replisomes are disassembled and unloaded from chromatin. A key process in replisome disassembly is the unloading of CMG helicases (CDC45–MCM–GINS), which is initiated in Caenorhabditis elegans and Xenopus laevis by the E3 ubiquitin ligase CRL2LRR1. Here, we show that human cells lacking LRR1 fail to unload CMG helicases and accumulate increasing amounts of chromatin-bound replisome components as cells progress through S phase. Markedly, we demonstrate that the failure to disassemble replisomes reduces the rate of DNA replication increasingly throughout S phase by sequestering rate-limiting replisome components on chromatin and blocking their recycling. Continued binding of CMG helicases to chromatin during G2 phase blocks mitosis by activating an ATR-mediated G2/M checkpoint. Finally, we provide evidence that LRR1 is an essential gene for human cell division, suggesting that CRL2LRR1 enzyme activity is required for the proliferation of cancer cells and is thus a potential target for cancer therapy.
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Affiliation(s)
- Yilin Fan
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA.,Department of Cell and Developmental Biology, Weill Cornell Medicine, New York, NY
| | - Marielle S Köberlin
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA
| | - Nalin Ratnayeke
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA.,Department of Cell and Developmental Biology, Weill Cornell Medicine, New York, NY
| | - Chad Liu
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA
| | - Madhura Deshpande
- Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine, Weill Cornell Medicine, New York, NY
| | - Jeannine Gerhardt
- Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine, Weill Cornell Medicine, New York, NY.,Department of Obstetrics and Gynecology, Weill Cornell Medicine, New York, NY
| | - Tobias Meyer
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA.,Department of Cell and Developmental Biology, Weill Cornell Medicine, New York, NY
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10
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Villa F, Fujisawa R, Ainsworth J, Nishimura K, Lie‐A‐Ling M, Lacaud G, Labib KPM. CUL2 LRR1 , TRAIP and p97 control CMG helicase disassembly in the mammalian cell cycle. EMBO Rep 2021; 22:e52164. [PMID: 33590678 PMCID: PMC7926238 DOI: 10.15252/embr.202052164] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 12/16/2020] [Accepted: 01/07/2021] [Indexed: 11/26/2022] Open
Abstract
The eukaryotic replisome is disassembled in each cell cycle, dependent upon ubiquitylation of the CMG helicase. Studies of Saccharomyces cerevisiae, Caenorhabditis elegans and Xenopus laevis have revealed surprising evolutionary diversity in the ubiquitin ligases that control CMG ubiquitylation, but regulated disassembly of the mammalian replisome has yet to be explored. Here, we describe a model system for studying the ubiquitylation and chromatin extraction of the mammalian CMG replisome, based on mouse embryonic stem cells. We show that the ubiquitin ligase CUL2LRR1 is required for ubiquitylation of the CMG-MCM7 subunit during S-phase, leading to disassembly by the p97 ATPase. Moreover, a second pathway of CMG disassembly is activated during mitosis, dependent upon the TRAIP ubiquitin ligase that is mutated in primordial dwarfism and mis-regulated in various cancers. These findings indicate that replisome disassembly in diverse metazoa is regulated by a conserved pair of ubiquitin ligases, distinct from those present in other eukaryotes.
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Affiliation(s)
- Fabrizio Villa
- The MRC Protein Phosphorylation and Ubiquitylation UnitSchool of Life SciencesUniversity of DundeeDundeeUK
| | - Ryo Fujisawa
- The MRC Protein Phosphorylation and Ubiquitylation UnitSchool of Life SciencesUniversity of DundeeDundeeUK
| | - Johanna Ainsworth
- The MRC Protein Phosphorylation and Ubiquitylation UnitSchool of Life SciencesUniversity of DundeeDundeeUK
| | - Kohei Nishimura
- The MRC Protein Phosphorylation and Ubiquitylation UnitSchool of Life SciencesUniversity of DundeeDundeeUK
- Division of Biological ScienceGraduate School of ScienceNagoya UniversityNagoyaJapan
| | - Michael Lie‐A‐Ling
- Cancer Research U.K. Manchester InstituteThe University of ManchesterAlderley ParkUK
| | - Georges Lacaud
- Cancer Research U.K. Manchester InstituteThe University of ManchesterAlderley ParkUK
| | - Karim PM Labib
- The MRC Protein Phosphorylation and Ubiquitylation UnitSchool of Life SciencesUniversity of DundeeDundeeUK
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11
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Bayer EA, Sun H, Rafi I, Hobert O. Temporal, Spatial, Sexual and Environmental Regulation of the Master Regulator of Sexual Differentiation in C. elegans. Curr Biol 2020; 30:3604-3616.e3. [DOI: 10.1016/j.cub.2020.06.060] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 05/04/2020] [Accepted: 06/17/2020] [Indexed: 12/23/2022]
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12
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Liang M, Wang H, He C, Zhang K, Hu K. LncRNA-Gm2044 is transcriptionally activated by A-MYB and regulates Sycp1 expression as a miR-335-3p sponge in mouse spermatocyte-derived GC-2spd(ts) cells. Differentiation 2020; 114:49-57. [PMID: 32585553 DOI: 10.1016/j.diff.2020.05.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 04/26/2020] [Accepted: 05/11/2020] [Indexed: 02/07/2023]
Abstract
Long noncoding RNAs (lncRNAs) have been shown to execute key roles in spermatogenesis. However, little is known about how lncRNAs gene expression is itself regulated in the germ cells of testis. We previously demonstrated that high expression of lncRNA-Gm2044 exists in spermatocytes and can regulate male germ cell proliferation. Here, the transcriptional regulation of lnRNA-Gm2044 expression in spermatocytes and the downstream signaling were further explored. A bioinformatics assessment predicted two potential binding-sites for the spermatocyte-specific transcription factor A-MYB in the promoter region of lncRNA-Gm2044. Our results proved that the transcription factor A-MYB promotes the expression of lncRNA-Gm2044 in mouse spermatocyte-derived GC-2spd(ts) cells. ChIP and luciferase assays verified that A-MYB mainly binds to the distal promoter region (-819 bp relative to the transcription start site) of lncRNA-Gm2044 and regulates lncRNA-Gm2044 expression through the -819 bp binding-site. In addition, we confirmed that lncRNA-Gm2044 functions as a miR-335-3p sponge to enhance the levels of miR-335-3p's direct target protein, Sycp1. Furthermore, A-MYB can up-regulate Sycp1 expression and down-regulate GC-2spd(ts) cell proliferation by activating its target, lncRNA-Gm2044. Overexpression of lncRNA-Gm2044 or knockdown of miR-335-3p can, at least partially, rescue the effects of A-MYB on Sycp1 expression and GC-2spd(ts) cell proliferation.Taken together, our results provide new information on the mechanistic roles of lncRNA-miRNA in transcription factor A-MYB regulation of spermatocyte function.
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Affiliation(s)
- Meng Liang
- School of Life Science, Bengbu Medical College, Bengbu, Anhui, People's Republic of China.
| | - Haiyan Wang
- School of Life Science, Bengbu Medical College, Bengbu, Anhui, People's Republic of China
| | - Chaofan He
- School of Life Science, Bengbu Medical College, Bengbu, Anhui, People's Republic of China
| | - Kejia Zhang
- School of Life Science, Bengbu Medical College, Bengbu, Anhui, People's Republic of China
| | - Ke Hu
- School of Life Science, Bengbu Medical College, Bengbu, Anhui, People's Republic of China.
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13
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Liu X, Zurlo G, Zhang Q. The Roles of Cullin-2 E3 Ubiquitin Ligase Complex in Cancer. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1217:173-186. [PMID: 31898228 DOI: 10.1007/978-981-15-1025-0_11] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Posttranslational protein modifications play an important role in regulating protein stability and cellular function. There are at least eight Cullin family members. Among them, Cullin-2 forms a functional E3 ligase complex with elongin B, elongin C, RING-box protein 1 (RBX1, also called ROC1), as well as the substrate recognition subunit (SRS) to promote the substrate ubiquitination and degradation. In this book chapter, we will review Cullin-2 E3 ligase complexes that include various SRS proteins, including von Hippel Lindau (pVHL), leucine-rich repeat protein-1 (LRR-1), preferentially expressed antigen of melanoma (PRAME), sex-determining protein FEM-1 and early embryogenesis protein ZYG-11. We will focus on the VHL signaling pathway in clear cell renal cell carcinoma (ccRCC), which may reveal various therapeutic avenues in treating this lethal cancer.
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Affiliation(s)
- Xijuan Liu
- Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Giada Zurlo
- Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC, USA.,Department of Pathology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Qing Zhang
- Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC, USA. .,Department of Pharmacology, University of North Carolina, Chapel Hill, NC, USA. .,Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC, USA. .,Department of Pathology, UT Southwestern Medical Center, Dallas, TX, USA.
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14
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Alleva B, Clausen S, Koury E, Hefel A, Smolikove S. CRL4 regulates recombination and synaptonemal complex aggregation in the Caenorhabditis elegans germline. PLoS Genet 2019; 15:e1008486. [PMID: 31738749 PMCID: PMC6886871 DOI: 10.1371/journal.pgen.1008486] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 12/02/2019] [Accepted: 10/21/2019] [Indexed: 01/08/2023] Open
Abstract
To maintain the integrity of the genome, meiotic DNA double strand breaks (DSBs) need to form by the meiosis-specific nuclease Spo11 and be repaired by homologous recombination. One class of products formed by recombination are crossovers, which are required for proper chromosome segregation in the first meiotic division. The synaptonemal complex (SC) is a protein structure that connects homologous chromosomes during meiotic prophase I. The proper assembly of the SC is important for recombination, crossover formation, and the subsequent chromosome segregation. Here we identify the components of Cullin RING E3 ubiquitin ligase 4 (CRL4) that play a role in SC assembly in Caenorhabditis elegans. Mutants of the CRL4 complex (cul-4, ddb-1, and gad-1) show defects in SC assembly manifested in the formation of polycomplexes (PCs), impaired progression of meiotic recombination, and reduction in crossover numbers. PCs that are formed in cul-4 mutants lack the mobile properties of wild type SC, but are likely not a direct target of ubiquitination. In C. elegans, SC assembly does not require recombination and there is no evidence that PC formation is regulated by recombination as well. However, in one cul-4 mutant PC formation is dependent upon early meiotic recombination, indicating that proper assembly of the SC can be diminished by recombination in some scenarios. Lastly, our studies suggest that CUL-4 deregulation leads to transposition of the Tc3 transposable element, and defects in formation of SPO-11-mediated DSBs. Our studies highlight previously unknown functions of CRL4 in C. elegans meiosis and show that CUL-4 likely plays multiple roles in meiosis that are essential for maintaining genome integrity. Defects in the formation of the structure named the synaptonemal complex (SC) lead to the missegregation of chromosomes in the divisions that generate sperm and egg cells. In humans, this chromosome missegregation is associated with infertility and developmental disabilities of the surviving progeny. Abnormal SC structures composed of misfolded and aggregated SC proteins are associated with an inability to properly repair DNA damage and accurately segregate meiotic chromosomes. How SC proteins assemble such that they do not form misfolded protein aggregates is poorly understood. The germlines of nematodes (Caenorhabditis elegans) that lack protein components of the Cullin 4 E3 Ubiquitin ligase complex (CRL4), have defects in the formation of the SC that can be due to misfolding of SC proteins and their aggregation. CRL4 appears to be involved in other germline functions that directly affect chromosome stability (DNA damage repair and transposition), indicating that CRL4 has a central function in the formation of functional sperm and egg cells.
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Affiliation(s)
- Benjamin Alleva
- The department of Biology, The University of Iowa, Iowa City, Iowa, United States of America
| | - Sean Clausen
- The department of Biology, The University of Iowa, Iowa City, Iowa, United States of America
| | - Emily Koury
- The department of Biology, The University of Iowa, Iowa City, Iowa, United States of America
| | - Adam Hefel
- The department of Biology, The University of Iowa, Iowa City, Iowa, United States of America
| | - Sarit Smolikove
- The department of Biology, The University of Iowa, Iowa City, Iowa, United States of America
- * E-mail:
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15
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Mutlu B, Chen HM, Gutnik S, Hall DH, Keppler-Ross S, Mango SE. Distinct functions and temporal regulation of methylated histone H3 during early embryogenesis. Development 2019; 146:dev174516. [PMID: 31540912 PMCID: PMC6803369 DOI: 10.1242/dev.174516] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 09/09/2019] [Indexed: 01/25/2023]
Abstract
During the first hours of embryogenesis, formation of higher-order heterochromatin coincides with the loss of developmental potential. Here, we examine the relationship between these two events, and we probe the processes that contribute to the timing of their onset. Mutations that disrupt histone H3 lysine 9 (H3K9) methyltransferases reveal that the methyltransferase MET-2 helps terminate developmental plasticity, through mono- and di-methylation of H3K9 (me1/me2), and promotes heterochromatin formation, through H3K9me3. Although loss of H3K9me3 perturbs formation of higher-order heterochromatin, embryos are still able to terminate plasticity, indicating that the two processes can be uncoupled. Methylated H3K9 appears gradually in developing C. elegans embryos and depends on nuclear localization of MET-2. We find that the timing of H3K9me2 and nuclear MET-2 is sensitive to rapid cell cycles, but not to zygotic genome activation or cell counting. These data reveal distinct roles for different H3K9 methylation states in the generation of heterochromatin and loss of developmental plasticity by MET-2, and identify the cell cycle as a crucial parameter of MET-2 regulation.
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Affiliation(s)
- Beste Mutlu
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Huei-Mei Chen
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Silvia Gutnik
- Biozentrum, University of Basel, 4056 Basel, Switzerland
| | - David H Hall
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | | | - Susan E Mango
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
- Biozentrum, University of Basel, 4056 Basel, Switzerland
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16
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Ulicna L, Rohozkova J, Hozak P. Multiple Aspects of PIP2 Involvement in C. elegans Gametogenesis. Int J Mol Sci 2018; 19:ijms19092679. [PMID: 30201859 PMCID: PMC6163852 DOI: 10.3390/ijms19092679] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 08/28/2018] [Accepted: 09/05/2018] [Indexed: 12/20/2022] Open
Abstract
One of the most studied phosphoinositides is phosphatidylinositol 4,5-bisphosphate (PIP2), which localizes to the plasma membrane, nuclear speckles, small foci in the nucleoplasm, and to the nucleolus in mammalian cells. Here, we show that PIP2 also localizes to the nucleus in prophase I, during the gametogenesis of C. elegans hermaphrodite. The depletion of PIP2 by type I PIP kinase (PPK-1) kinase RNA interference results in an altered chromosome structure and leads to various defects during meiotic progression. We observed a decreased brood size and aneuploidy in progeny, defects in synapsis, and crossover formation. The altered chromosome structure is reflected in the increased transcription activity of a tightly regulated process in prophase I. To elucidate the involvement of PIP2 in the processes during the C. elegans development, we identified the PIP2-binding partners, leucine-rich repeat (LRR-1) protein and proteasome subunit beta 4 (PBS-4), pointing to its involvement in the ubiquitin–proteasome pathway.
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Affiliation(s)
- Livia Ulicna
- Department of Biology of the Cell Nucleus, Institute of Molecular Genetics of the Czech Academy of Sciences, v.v.i., Prague 142 20, Czech Republic.
| | - Jana Rohozkova
- Department of Epigenetics of the Cell Nucleus, Institute of Molecular Genetics of the Czech Academy of Sciences, v.v.i., Division BIOCEV, Vestec 252 50, Czech Republic.
| | - Pavel Hozak
- Department of Biology of the Cell Nucleus, Institute of Molecular Genetics of the Czech Academy of Sciences, v.v.i., Prague 142 20, Czech Republic.
- Department of Epigenetics of the Cell Nucleus, Institute of Molecular Genetics of the Czech Academy of Sciences, v.v.i., Division BIOCEV, Vestec 252 50, Czech Republic.
- Microscopy Centre, Institute of Molecular Genetics of the Czech Academy of Sciences, v.v.i., Prague 142 20, Czech Republic.
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17
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Gutnik S, Thomas Y, Guo Y, Stoecklin J, Neagu A, Pintard L, Merlet J, Ciosk R. PRP-19, a conserved pre-mRNA processing factor and E3 ubiquitin ligase, inhibits the nuclear accumulation of GLP-1/Notch intracellular domain. Biol Open 2018; 7:bio034066. [PMID: 30012553 PMCID: PMC6078339 DOI: 10.1242/bio.034066] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 06/15/2018] [Indexed: 01/13/2023] Open
Abstract
The Notch signalling pathway is a conserved and widespread signalling paradigm, and its misregulation has been implicated in numerous disorders, including cancer. The output of Notch signalling depends on the nuclear accumulation of the Notch receptor intracellular domain (ICD). Using the Caenorhabditis elegans germline, where GLP-1/Notch-mediated signalling is essential for maintaining stem cells, we monitored GLP-1 in vivo We found that the nuclear enrichment of GLP-1 ICD is dynamic: while the ICD is enriched in germ cell nuclei during larval development, it is depleted from the nuclei in adult germlines. We found that this pattern depends on the ubiquitin proteolytic system and the splicing machinery and, identified the splicing factor PRP-19 as a candidate E3 ubiquitin ligase required for the nuclear depletion of GLP-1 ICD.
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Affiliation(s)
- Silvia Gutnik
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
- University of Basel, Petersplatz 1, 4001 Basel, Switzerland
| | - Yann Thomas
- Cell Cycle and Development, Institut Jacques Monod, UMR7592 CNRS - Université Paris Diderot, Sorbonne Paris Cité, F-75013 Paris, France
| | - Yanwu Guo
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0316 Oslo, Norway
| | - Janosch Stoecklin
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
- University of Basel, Petersplatz 1, 4001 Basel, Switzerland
| | - Anca Neagu
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Lionel Pintard
- Cell Cycle and Development, Institut Jacques Monod, UMR7592 CNRS - Université Paris Diderot, Sorbonne Paris Cité, F-75013 Paris, France
| | - Jorge Merlet
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
- Sorbonne Université, CNRS, Institut de Biologie Paris-Seine (IBPS), Developmental Biology Laboratory, UMR 7622, F-75005 Paris, France
| | - Rafal Ciosk
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0316 Oslo, Norway
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
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18
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Kumar GA, Subramaniam K. PUF-8 facilitates homologous chromosome pairing by promoting proteasome activity during meiotic entry in C. elegans. Development 2018. [PMID: 29540500 DOI: 10.1242/dev.163949] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Pairing of homologous chromosomes is essential for genetic recombination during gametogenesis. In many organisms, chromosome ends are attached to cytoplasmic dynein, and dynein-driven chromosomal movements facilitate the pairing process. Factors that promote or control the cytoskeletal tethering of chromosomes are largely unknown. Here, we show that the conserved RNA-binding protein PUF-8 facilitates the tethering and pairing processes in the C. elegans germline by promoting proteasome activity. We have isolated a hypomorphic allele of pas-1, which encodes a proteasome core subunit, and find that the homologous chromosomes fail to pair in the puf-8; pas-1 double mutant due to failure of chromosome tethering. Our results reveal that the puf-8; pas-1 meiotic defects are caused by the loss of proteasome activity. The axis component HTP-3 accumulates prematurely in the double mutant, and reduction of its activity partially suppresses some of the puf-8; pas-1 meiotic defects, suggesting that HTP-3 might be an important target of the proteasome in promoting early meiotic events. In summary, our results reveal a role for the proteasome in chromosome tethering and identify PUF-8 as a regulator of proteasome activity during early meiosis.
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Affiliation(s)
- Ganga Anil Kumar
- Department of Biotechnology, Indian Institute of Technology-Madras, Chennai 600036, India.,Department of Biological Sciences & Bioengineering, Indian Institute of Technology, Kanpur 208016, India
| | - Kuppuswamy Subramaniam
- Department of Biotechnology, Indian Institute of Technology-Madras, Chennai 600036, India
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19
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Wang S, Xia W, Qiu M, Wang X, Jiang F, Yin R, Xu L. Atlas on substrate recognition subunits of CRL2 E3 ligases. Oncotarget 2018; 7:46707-46716. [PMID: 27107416 PMCID: PMC5216831 DOI: 10.18632/oncotarget.8732] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 04/02/2016] [Indexed: 12/16/2022] Open
Abstract
The Cullin2-type ubiquitin ligases belong to the Cullin-Ring Ligase (CRL) family, which is a crucial determinant of proteasome-based degradation processes in eukaryotes. Because of the finding of von Hippel-Lindau tumor suppressor (VHL), the Cullin2-type ubiquitin ligases gain focusing in the research of many diseases, especially in tumors. These multisubunit enzymes are composed of the Ring finger protein, the Cullin2 scaffold protein, the Elongin B&C linker protein and the variant substrate recognition subunits (SRSs), among which the Cullin2 scaffold protein is the determining factor of the enzyme mechanism. Substrate recognition of Cullin2-type ubiquitin ligases depends on SRSs and results in the degradation of diseases associated substrates by intracellular signaling events. This review focuses on the diversity and the multifunctionality of SRSs in the Cullin2-type ubiquitin ligases, including VHL, LRR-1, FEM1b, PRAME and ZYG11. Recently, as more SRSs are being discovered and more aspects of substrate recognition have been illuminated, insight into the relationship between Cul2-dependent SRSs and substrates provides a new area for cancer research.
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Affiliation(s)
- Siwei Wang
- Department of Thoracic Surgery, Nanjing Medical University Affiliated Cancer Hospital, Jiangsu Key Laboratory of Molecular and Translational Cancer Research, Cancer Institute of Jiangsu Province, Nanjing, China.,The Fourth Clinical College of Nanjing Medical University, Nanjing, China
| | - Wenjia Xia
- Department of Thoracic Surgery, Nanjing Medical University Affiliated Cancer Hospital, Jiangsu Key Laboratory of Molecular and Translational Cancer Research, Cancer Institute of Jiangsu Province, Nanjing, China.,The Fourth Clinical College of Nanjing Medical University, Nanjing, China
| | - Mantang Qiu
- Department of Thoracic Surgery, Nanjing Medical University Affiliated Cancer Hospital, Jiangsu Key Laboratory of Molecular and Translational Cancer Research, Cancer Institute of Jiangsu Province, Nanjing, China.,The Fourth Clinical College of Nanjing Medical University, Nanjing, China
| | - Xin Wang
- Department of Thoracic Surgery, Nanjing Medical University Affiliated Cancer Hospital, Jiangsu Key Laboratory of Molecular and Translational Cancer Research, Cancer Institute of Jiangsu Province, Nanjing, China.,The Fourth Clinical College of Nanjing Medical University, Nanjing, China
| | - Feng Jiang
- Department of Thoracic Surgery, Nanjing Medical University Affiliated Cancer Hospital, Jiangsu Key Laboratory of Molecular and Translational Cancer Research, Cancer Institute of Jiangsu Province, Nanjing, China
| | - Rong Yin
- Department of Thoracic Surgery, Nanjing Medical University Affiliated Cancer Hospital, Jiangsu Key Laboratory of Molecular and Translational Cancer Research, Cancer Institute of Jiangsu Province, Nanjing, China
| | - Lin Xu
- Department of Thoracic Surgery, Nanjing Medical University Affiliated Cancer Hospital, Jiangsu Key Laboratory of Molecular and Translational Cancer Research, Cancer Institute of Jiangsu Province, Nanjing, China
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20
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Hiraki H, Kagoshima H, Kraus C, Schiffer PH, Ueta Y, Kroiher M, Schierenberg E, Kohara Y. Genome analysis of Diploscapter coronatus: insights into molecular peculiarities of a nematode with parthenogenetic reproduction. BMC Genomics 2017; 18:478. [PMID: 28646875 PMCID: PMC5483258 DOI: 10.1186/s12864-017-3860-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 06/13/2017] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Sexual reproduction involving the fusion of egg and sperm is prevailing among eukaryotes. In contrast, the nematode Diploscapter coronatus, a close relative of the model Caenorhabditis elegans, reproduces parthenogenetically. Neither males nor sperm have been observed and some steps of meiosis are apparently skipped in this species. To uncover the genomic changes associated with the evolution of parthenogenesis in this nematode, we carried out a genome analysis. RESULTS We obtained a 170 Mbp draft genome in only 511 scaffolds with a N50 length of 1 Mbp. Nearly 90% of these scaffolds constitute homologous pairs with a 5.7% heterozygosity on average and inversions and translocations, meaning that the 170 Mbp sequences correspond to the diploid genome. Fluorescent staining shows that the D. coronatus genome consists of two chromosomes (2n = 2). In our genome annotation, we found orthologs of 59% of the C. elegans genes. However, a number of genes were missing or very divergent. These include genes involved in sex determination (e.g. xol-1, tra-2) and meiosis (e.g. the kleisins rec-8 and coh-3/4) giving a possible explanation for the absence of males and the second meiotic division. The high degree of heterozygosity allowed us to analyze the expression level of individual alleles. Most of the homologous pairs show very similar expression levels but others exhibit a 2-5-fold difference. CONCLUSIONS Our high-quality draft genome of D. coronatus reveals the peculiarities of the genome of parthenogenesis and provides some clues to the genetic basis for parthenogenetic reproduction. This draft genome should be the basis to elucidate fundamental questions related to parthenogenesis such as its origin and mechanisms through comparative analyses with other nematodes. Furthermore, being the closest outgroup to the genus Caenorhabditis, the draft genome will help to disclose many idiosyncrasies of the model C. elegans and its congeners in future studies.
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Affiliation(s)
- Hideaki Hiraki
- Genome Biology Laboratory, National Institute of Genetics, Mishima, Japan
| | - Hiroshi Kagoshima
- Genome Biology Laboratory, National Institute of Genetics, Mishima, Japan
- Transdisciplinary Research Integration Center, Research Organization of Information and Systems, Tokyo, Japan
| | | | | | - Yumiko Ueta
- Genome Biology Laboratory, National Institute of Genetics, Mishima, Japan
| | - Michael Kroiher
- Zoologisches Institut, Universität zu Köln, Cologne, NRW Germany
| | | | - Yuji Kohara
- Genome Biology Laboratory, National Institute of Genetics, Mishima, Japan
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21
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Gambus A. Termination of Eukaryotic Replication Forks. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1042:163-187. [DOI: 10.1007/978-981-10-6955-0_8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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22
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Son M, Kawasaki I, Oh BK, Shim YH. LIN-23, an E3 Ubiquitin Ligase Component, Is Required for the Repression of CDC-25.2 Activity during Intestinal Development in Caenorhabditis elegans. Mol Cells 2016; 39:834-840. [PMID: 27871172 PMCID: PMC5125940 DOI: 10.14348/molcells.2016.0238] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 11/02/2016] [Accepted: 11/07/2017] [Indexed: 11/27/2022] Open
Abstract
Caenorhabditis elegans (C. elegans) utilizes two different cell-cycle modes, binucleations during the L1 larval stage and endoreduplications at four larval moltings, for its postembryonic intestinal development. Previous genetic studies indicated that CDC-25.2 is specifically required for binucleations at the L1 larval stage and is repressed before endoreduplications. Furthermore, LIN-23, the C. elegans β-TrCP ortholog, appears to function as a repressor of CDC-25.2 to prevent excess intestinal divisions. We previously reported that intestinal hyperplasia in lin-23(e1883) mutants was effectively suppressed by the RNAi depletion of cdc-25.2. Nevertheless, LIN-23 targeting CDC-25.2 for ubiquitination as a component of E3 ubiquitin ligase has not yet been tested. In this study, LIN-23 is shown to be the major E3 ubiquitin ligase component, recognizing CDC-25.2 to repress their activities for proper transition of cell-cycle modes during the C. elegans postembryonic intestinal development. In addition, for the first time that LIN-23 physically interacts with both CDC-25.1 and CDC-25.2 and facilitates ubiquitination for timely regulation of their activities during the intestinal development.
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Affiliation(s)
- Miseol Son
- Department of Bioscience and Biotechnology, Konkuk University, Seoul 05029,
Korea
| | - Ichiro Kawasaki
- Department of Bioscience and Biotechnology, Konkuk University, Seoul 05029,
Korea
| | - Bong-Kyeong Oh
- Institute of Medical Science, Hanyang University College of Medicine, Seoul 04763,
Korea
| | - Yhong-Hee Shim
- Department of Bioscience and Biotechnology, Konkuk University, Seoul 05029,
Korea
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23
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RNAi-Based Suppressor Screens Reveal Genetic Interactions Between the CRL2LRR-1 E3-Ligase and the DNA Replication Machinery in Caenorhabditis elegans. G3-GENES GENOMES GENETICS 2016; 6:3431-3442. [PMID: 27543292 PMCID: PMC5068962 DOI: 10.1534/g3.116.033043] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Cullin-RING E3-Ligases (CRLs), the largest family of E3 ubiquitin-Ligases, regulate diverse cellular processes by promoting ubiquitination of target proteins. The evolutionarily conserved Leucine Rich Repeat protein 1 (LRR-1) is a substrate-recognition subunit of a CRL2LRR-1 E3-ligase. Here we provide genetic evidence supporting a role of this E3-enzyme in the maintenance of DNA replication integrity in Caenorhabditis elegans. Through RNAi-based suppressor screens of lrr-1(0) and cul-2(or209ts) mutants, we identified two genes encoding components of the GINS complex, which is part of the Cdc45-MCM-GINS (CMG) replicative helicase, as well as CDC-7 and MUS-101, which drives the assembly of the CMG helicase during DNA replication. In addition, we identified the core components of the ATR/ATL-1 DNA replication checkpoint pathway (MUS-101, ATL-1, CLSP-1, CHK-1). These results suggest that the CRL2LRR-1 E3-ligase acts to modify or degrade factor(s) that would otherwise misregulate the replisome, eventually leading to the activation of the DNA replication checkpoint.
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24
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Regulation of the MEI-1/MEI-2 Microtubule-Severing Katanin Complex in Early Caenorhabditis elegans Development. G3-GENES GENOMES GENETICS 2016; 6:3257-3268. [PMID: 27527792 PMCID: PMC5068946 DOI: 10.1534/g3.116.031666] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
After fertilization, rapid changes of the Caenorhabditis elegans cytoskeleton occur in the transition from meiosis to mitosis, requiring precise regulation. The MEI-1/MEI-2 katanin microtubule-severing complex is essential for meiotic spindle formation but must be quickly inactivated to allow for proper formation of the mitotic spindle. MEI-1/MEI-2 inactivation is dependent on multiple redundant pathways. The primary pathway employs the MEL-26 substrate adaptor for the CUL-3/cullin-based E3 ubiquitin ligase, which targets MEI-1 for proteosomal degradation. Here, we used quantitative antibody staining to measure MEI-1 levels to determine how other genes implicated in MEI-1 regulation act relative to CUL-3/MEL-26. The anaphase-promoting complex/cyclosome, APC/C, the DYRK (Dual-specificity tyrosine-regulated kinase), MBK-2, and the CUL-2-based E3 ubiquitin ligase act together to degrade MEI-1, in parallel to MEL-26/CUL-3. CUL-2 is known to keep MEL-26 low during meiosis, so CUL-2 apparently changes its target from MEL-26 in meiosis to MEI-1 in mitosis. RFL-1, an activator of cullin E3 ubiquitin ligases, activates CUL-2 but not CUL-3 for MEI-1 elimination. HECD-1 (HECT/Homologous to the E6AP carboxyl terminus domain) E3 ligase acts as a MEI-1 activator in meiosis but functions as an inhibitor during mitosis, without affecting levels of MEI-1 or MEI-2. Our results highlight the multiple layers of MEI-1 regulation that are required during the switch from the meiotic to mitotic modes of cell division.
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Cai W, Yang H. The structure and regulation of Cullin 2 based E3 ubiquitin ligases and their biological functions. Cell Div 2016; 11:7. [PMID: 27222660 PMCID: PMC4878042 DOI: 10.1186/s13008-016-0020-7] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 05/11/2016] [Indexed: 11/23/2022] Open
Abstract
Background Cullin-RING E3 ubiquitin ligase complexes play a central role in targeting cellular proteins for ubiquitination-dependent protein turnover through 26S proteasome. Cullin-2 is a member of the Cullin family, and it serves as a scaffold protein for Elongin B and C, Rbx1 and various substrate recognition receptors to form E3 ubiquitin ligases. Main body of the abstract First, the composition, structure and the regulation of Cullin-2 based E3 ubiquitin ligases were introduced. Then the targets, the biological functions of complexes that use VHL, Lrr-1, Fem1b, Prame, Zyg-11, BAF250, Rack1 as substrate targeting subunits were described, and their involvement in diseases was discussed. A small molecule inhibitor of Cullins as a potential anti-cancer drug was introduced. Furthermore, proteins with VHL box that might bind to Cullin-2 were described. Finally, how different viral proteins form E3 ubiquitin ligase complexes with Cullin-2 to counter host viral defense were explained. Conclusions Cullin-2 based E3 ubiquitin ligases, using many different substrate recognition receptors, recognize a number of substrates and regulate their protein stability. These complexes play critical roles in biological processes and diseases such as cancer, germline differentiation and viral defense. Through the better understanding of their biology, we can devise and develop new therapeutic strategies to treat cancers, inherited diseases and viral infections.
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Affiliation(s)
- Weijia Cai
- Department of Pathology and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107 USA
| | - Haifeng Yang
- Department of Pathology and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107 USA
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Nelson CR, Hwang T, Chen PH, Bhalla N. TRIP13PCH-2 promotes Mad2 localization to unattached kinetochores in the spindle checkpoint response. J Cell Biol 2015; 211:503-16. [PMID: 26527744 PMCID: PMC4639874 DOI: 10.1083/jcb.201505114] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 09/24/2015] [Indexed: 12/19/2022] Open
Abstract
The ability of the conserved ATPase TRIP13PCH-2 to disassemble a Mad2-containing complex is critical to promote the spindle checkpoint response by contributing to the robust localization of Mad2 to unattached kinetochores. The spindle checkpoint acts during cell division to prevent aneuploidy, a hallmark of cancer. During checkpoint activation, Mad1 recruits Mad2 to kinetochores to generate a signal that delays anaphase onset. Yet, whether additional factors contribute to Mad2’s kinetochore localization remains unclear. Here, we report that the conserved AAA+ ATPase TRIP13PCH-2 localizes to unattached kinetochores and is required for spindle checkpoint activation in Caenorhabditis elegans. pch-2 mutants effectively localized Mad1 to unattached kinetochores, but Mad2 recruitment was significantly reduced. Furthermore, we show that the C. elegans orthologue of the Mad2 inhibitor p31(comet)CMT-1 interacts with TRIP13PCH-2 and is required for its localization to unattached kinetochores. These factors also genetically interact, as loss of p31(comet)CMT-1 partially suppressed the requirement for TRIP13PCH-2 in Mad2 localization and spindle checkpoint signaling. These data support a model in which the ability of TRIP13PCH-2 to disassemble a p31(comet)/Mad2 complex, which has been well characterized in the context of checkpoint silencing, is also critical for spindle checkpoint activation.
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Affiliation(s)
- Christian R Nelson
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064
| | - Tom Hwang
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064
| | - Pin-Hsi Chen
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064
| | - Needhi Bhalla
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064
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Rabilotta A, Desrosiers M, Labbé JC. CDK-1 and two B-type cyclins promote PAR-6 stabilization during polarization of the early C. elegans embryo. PLoS One 2015; 10:e0117656. [PMID: 25658117 PMCID: PMC4319824 DOI: 10.1371/journal.pone.0117656] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 12/30/2014] [Indexed: 01/08/2023] Open
Abstract
In the C. elegans embryo, formation of an antero-posterior axis of polarity relies on signaling by the conserved PAR proteins, which localize asymmetrically in two mutually exclusive groups at the embryonic cortex. Depletion of any PAR protein causes a loss of polarity and embryonic lethality. A genome-wide RNAi screen previously identified two B-type cyclins, cyb-2.1 and cyb-2.2, as suppressors of par-2(it5ts) lethality. We found that the loss of cyb-2.1 or cyb-2.2 suppressed the lethality and polarity defects of par-2(it5ts) mutants and that these cyclins act in cell polarity with their cyclin-dependent kinase partner, CDK-1. Interestingly, cyb-2.1; cyb-2.2 double mutants did not show defects in cell cycle progression or timing of polarity establishment, suggesting that they regulate polarity independently of their typical role in cell cycle progression. Loss of both cyclin genes or of cdk-1 resulted in a decrease in PAR-6 levels in the embryo. Furthermore, the activity of the cullin CUL-2 was required to achieve suppression of par-2 lethality when both cyclins were absent. Our results support a model in which CYB-2.1/2/CDK-1 antagonize CUL-2 activity to promote stabilization of PAR-6 levels during polarization of the early C. elegans embryo. They also suggest that CYB-2.1 and CYB-2.2 contribute to the coupling of cell cycle progression and asymmetric segregation of cell fate determinants.
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Affiliation(s)
- Alexia Rabilotta
- Institute of Research in Immunology and Cancer (IRIC), Université de Montréal, Montréal, Quebec, Canada
| | - Marianne Desrosiers
- Institute of Research in Immunology and Cancer (IRIC), Université de Montréal, Montréal, Quebec, Canada
| | - Jean-Claude Labbé
- Institute of Research in Immunology and Cancer (IRIC), Université de Montréal, Montréal, Quebec, Canada
- Department of Pathology and Cell Biology, Université de Montréal, Montréal, Quebec, Canada
- * E-mail:
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The chromosome axis controls meiotic events through a hierarchical assembly of HORMA domain proteins. Dev Cell 2014; 31:487-502. [PMID: 25446517 DOI: 10.1016/j.devcel.2014.09.013] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Revised: 07/29/2014] [Accepted: 09/23/2014] [Indexed: 11/21/2022]
Abstract
Proteins of the HORMA domain family play central, but poorly understood, roles in chromosome organization and dynamics during meiosis. In Caenorhabditis elegans, four such proteins (HIM-3, HTP-1, HTP-2, and HTP-3) have distinct but overlapping functions. Through combined biochemical, structural, and in vivo analysis, we find that these proteins form hierarchical complexes through binding of their HORMA domains to cognate peptides within their partners' C-terminal tails, analogous to the "safety belt" binding mechanism of Mad2. These interactions are critical for recruitment of HIM-3, HTP-1, and HTP-2 to chromosome axes. HTP-3, in addition to recruiting the other HORMA domain proteins to the axis, plays an independent role in sister chromatid cohesion and double-strand break formation. Finally, we find that mammalian HORMAD1 binds a motif found both at its own C terminus and at that of HORMAD2, indicating that this mode of intermolecular association is a conserved feature of meiotic chromosome structure in eukaryotes.
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Subramanian VV, Hochwagen A. The meiotic checkpoint network: step-by-step through meiotic prophase. Cold Spring Harb Perspect Biol 2014; 6:a016675. [PMID: 25274702 DOI: 10.1101/cshperspect.a016675] [Citation(s) in RCA: 134] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The generation of haploid gametes by meiosis is a highly conserved process for sexually reproducing organisms that, in almost all cases, involves the extensive breakage of chromosomes. These chromosome breaks occur during meiotic prophase and are essential for meiotic recombination as well as the subsequent segregation of homologous chromosomes. However, their formation and repair must be carefully monitored and choreographed with nuclear dynamics and the cell division program to avoid the creation of aberrant chromosomes and defective gametes. It is becoming increasingly clear that an intricate checkpoint-signaling network related to the canonical DNA damage response is deeply interwoven with the meiotic program and preserves order during meiotic prophase. This meiotic checkpoint network (MCN) creates a wide range of dependent relationships controlling chromosome movement, chromosome pairing, chromatin structure, and double-strand break (DSB) repair. In this review, we summarize our current understanding of the MCN. We discuss commonalities and differences in different experimental systems, with a particular emphasis on the emerging design principles that control and limit cross talk between signals to ultimately ensure the faithful inheritance of chromosomes by the next generation.
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Affiliation(s)
| | - Andreas Hochwagen
- Department of Biology, New York University, New York, New York 10003
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Tocchini C, Keusch JJ, Miller SB, Finger S, Gut H, Stadler MB, Ciosk R. The TRIM-NHL protein LIN-41 controls the onset of developmental plasticity in Caenorhabditis elegans. PLoS Genet 2014; 10:e1004533. [PMID: 25167051 PMCID: PMC4148191 DOI: 10.1371/journal.pgen.1004533] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Accepted: 06/11/2014] [Indexed: 12/30/2022] Open
Abstract
The mechanisms controlling cell fate determination and reprogramming are fundamental for development. A profound reprogramming, allowing the production of pluripotent cells in early embryos, takes place during the oocyte-to-embryo transition. To understand how the oocyte reprogramming potential is controlled, we sought Caenorhabditis elegans mutants in which embryonic transcription is initiated precociously in germ cells. This screen identified LIN-41, a TRIM-NHL protein and a component of the somatic heterochronic pathway, as a temporal regulator of pluripotency in the germline. We found that LIN-41 is expressed in the cytoplasm of developing oocytes, which, in lin-41 mutants, acquire pluripotent characteristics of embryonic cells and form teratomas. To understand LIN-41 function in the germline, we conducted structure-function studies. In contrast to other TRIM-NHL proteins, we found that LIN-41 is unlikely to function as an E3 ubiquitin ligase. Similar to other TRIM-NHL proteins, the somatic function of LIN-41 is thought to involve mRNA regulation. Surprisingly, we found that mutations predicted to disrupt the association of LIN-41 with mRNA, which otherwise compromise LIN-41 function in the heterochronic pathway in the soma, have only minor effects in the germline. Similarly, LIN-41-mediated repression of a key somatic mRNA target is dispensable for the germline function. Thus, LIN-41 appears to function in the germline and the soma via different molecular mechanisms. These studies provide the first insight into the mechanism inhibiting the onset of embryonic differentiation in developing oocytes, which is required to ensure a successful transition between generations. Reprogramming into a naïve, pluripotent state during the oocyte-to-embryo transition is directed by the oocyte cytoplasm. To understand how this reprogramming is controlled, we searched for C. elegans mutants in which the activation of embryonic genome, a landmark event demarcating the switch from a germline- to embryo-specific transcription, is initiated precociously in germ cells. This screen identified a novel function for LIN-41, a member of the TRIM-NHL protein family, in preventing a premature onset of embryonic-like differentiation and teratoma formation in developing oocytes, thus ensuring a successful passage between generations. This is the first example of such a regulator in cells that are poised for embryonic development. Interestingly, the majority of molecular “roadblocks” to reprograming that have been identified so far are epigenetic regulators. However, we propose that, at least in germ cells, LIN-41-like regulators may fulfill an analogous role in the cytoplasm, which has possible implications for the generation of human pluripotent stem cells.
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Affiliation(s)
- Cristina Tocchini
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Jeremy J. Keusch
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Sarah B. Miller
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Susanne Finger
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Heinz Gut
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Michael B. Stadler
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- Swiss Institute of Bioinformatics, Basel, Switzerland
| | - Rafal Ciosk
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
- * E-mail:
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Wang X, Gupta P, Fairbanks J, Hansen D. Protein kinase CK2 both promotes robust proliferation and inhibits the proliferative fate in the C. elegans germ line. Dev Biol 2014; 392:26-41. [PMID: 24824786 DOI: 10.1016/j.ydbio.2014.05.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 04/02/2014] [Accepted: 05/02/2014] [Indexed: 11/18/2022]
Abstract
Stem cells are capable of both self-renewal (proliferation) and differentiation. Determining the regulatory mechanisms controlling the balance between stem cell proliferation and differentiation is not only an important biological question, but also holds the key for using stem cells as therapeutic agents. The Caenorhabditis elegans germ line has emerged as a valuable model to study the molecular mechanisms controlling stem cell behavior. In this study, we describe a large-scale RNAi screen that identified kin-10, which encodes the β subunit of protein kinase CK2, as a novel factor regulating stem cell proliferation in the C. elegans germ line. While a loss of kin-10 in an otherwise wild-type background results in a decrease in the number of proliferative cells, loss of kin-10 in sensitized genetic backgrounds results in a germline tumor. Therefore, kin-10 is not only necessary for robust proliferation, it also inhibits the proliferative fate. We found that kin-10's regulatory role in inhibiting the proliferative fate is carried out through the CK2 holoenzyme, rather than through a holoenzyme-independent function, and that it functions downstream of GLP-1/Notch signaling. We propose that a loss of kin-10 leads to a defect in CK2 phosphorylation of its downstream targets, resulting in abnormal activity of target protein(s) that are involved in the proliferative fate vs. differentiation decision. This eventually causes a shift towards the proliferative fate in the stem cell fate decision.
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Affiliation(s)
- Xin Wang
- Department of Biological Sciences, University of Calgary, 2500 University Drive, Calgary, Alberta, Canada T2N 1N4
| | - Pratyush Gupta
- Department of Biological Sciences, University of Calgary, 2500 University Drive, Calgary, Alberta, Canada T2N 1N4
| | - Jared Fairbanks
- Department of Biological Sciences, University of Calgary, 2500 University Drive, Calgary, Alberta, Canada T2N 1N4
| | - Dave Hansen
- Department of Biological Sciences, University of Calgary, 2500 University Drive, Calgary, Alberta, Canada T2N 1N4.
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Deshong AJ, Ye AL, Lamelza P, Bhalla N. A quality control mechanism coordinates meiotic prophase events to promote crossover assurance. PLoS Genet 2014; 10:e1004291. [PMID: 24762417 PMCID: PMC3998905 DOI: 10.1371/journal.pgen.1004291] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Accepted: 02/21/2014] [Indexed: 01/12/2023] Open
Abstract
Meiotic chromosome segregation relies on homologous chromosomes being linked by at least one crossover, the obligate crossover. Homolog pairing, synapsis and meiosis specific DNA repair mechanisms are required for crossovers but how they are coordinated to promote the obligate crossover is not well understood. PCH-2 is a highly conserved meiotic AAA+-ATPase that has been assigned a variety of functions; whether these functions reflect its conserved role has been difficult to determine. We show that PCH-2 restrains pairing, synapsis and recombination in C. elegans. Loss of pch-2 results in the acceleration of synapsis and homolog-dependent meiotic DNA repair, producing a subtle increase in meiotic defects, and suppresses pairing, synapsis and recombination defects in some mutant backgrounds. Some defects in pch-2 mutants can be suppressed by incubation at lower temperature and these defects increase in frequency in wildtype worms grown at higher temperature, suggesting that PCH-2 introduces a kinetic barrier to the formation of intermediates that support pairing, synapsis or crossover recombination. We hypothesize that this kinetic barrier contributes to quality control during meiotic prophase. Consistent with this possibility, defects in pch-2 mutants become more severe when another quality control mechanism, germline apoptosis, is abrogated or meiotic DNA repair is mildly disrupted. PCH-2 is expressed in germline nuclei immediately preceding the onset of stable homolog pairing and synapsis. Once chromosomes are synapsed, PCH-2 localizes to the SC and is removed in late pachytene, prior to SC disassembly, correlating with when homolog-dependent DNA repair mechanisms predominate in the germline. Indeed, loss of pch-2 results in premature loss of homolog access. Altogether, our data indicate that PCH-2 coordinates pairing, synapsis and recombination to promote crossover assurance. Specifically, we propose that the conserved function of PCH-2 is to destabilize pairing and/or recombination intermediates to slow their progression and ensure their fidelity during meiotic prophase. The production of sperm and eggs for sexual reproduction depends on meiosis. During this specialized cell division, homologous chromosomes are linked by at least one crossover recombination event, or chiasma, to promote their proper segregation. How events in meiotic prophase are coordinated to contribute to crossover assurance is not well understood. Here, we show that C. elegans PCH-2 regulates a variety of events during meiotic prophase to promote crossover assurance. In the absence of pch-2, pairing, synapsis and recombination are accelerated, resulting in defects in synapsis and crossover formation. We propose that PCH-2 restrains the events of meiotic prophase to coordinate them, ensure their fidelity and guarantee that each homolog pair has at least one crossover to promote proper meiotic chromosome segregation.
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Affiliation(s)
- Alison J. Deshong
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, California, United States of America
| | - Alice L. Ye
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, California, United States of America
| | - Piero Lamelza
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, California, United States of America
| | - Needhi Bhalla
- Department of Molecular, Cell and Developmental Biology, University of California, Santa Cruz, Santa Cruz, California, United States of America
- * E-mail:
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Ubiquitin-proteasome system in spermatogenesis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 759:181-213. [PMID: 25030765 DOI: 10.1007/978-1-4939-0817-2_9] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Spermatogenesis represents a complex succession of cell division and differentiation events resulting in the continuous formation of spermatozoa. Such a complex program requires precise expression of enzymes and structural proteins which is effected not only by regulation of gene transcription and translation, but also by targeted protein degradation. In this chapter, we review current knowledge about the role of the ubiquitin-proteasome system in spermatogenesis, describing both proteolytic and non-proteolytic functions of ubiquitination. Ubiquitination plays essential roles in the establishment of both spermatogonial stem cells and differentiating spermatogonia from gonocytes. It also plays critical roles in several key processes during meiosis such as genetic recombination and sex chromosome silencing. Finally, in spermiogenesis, we summarize current knowledge of the role of the ubiquitin-proteasome system in nucleosome removal and establishment of key structures in the mature spermatid. Many mechanisms remain to be precisely defined, but present knowledge indicates that research in this area has significant potential to translate into benefits that will address problems in both human and animal reproduction.
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Collado-Romero M, Alós E, Prieto P. Unravelling the proteomic profile of rice meiocytes during early meiosis. FRONTIERS IN PLANT SCIENCE 2014; 5:356. [PMID: 25104955 PMCID: PMC4109522 DOI: 10.3389/fpls.2014.00356] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 07/03/2014] [Indexed: 05/06/2023]
Abstract
Transfer of genetic traits from wild or related species into cultivated rice is nowadays an important aim in rice breeding. Breeders use genetic crosses to introduce desirable genes from exotic germplasms into cultivated rice varieties. However, in many hybrids there is only a low level of pairing (if existing) and recombination at early meiosis between cultivated rice and wild relative chromosomes. With the objective of getting deeper into the knowledge of the proteins involved in early meiosis, when chromosomes associate correctly in pairs and recombine, the proteome of isolated rice meiocytes has been characterized by nLC-MS/MS at every stage of early meiosis (prophase I). Up to 1316 different proteins have been identified in rice isolated meiocytes in early meiosis, being 422 exclusively identified in early prophase I (leptotene, zygotene, or pachytene). The classification of proteins in functional groups showed that 167 were related to chromatin structure and remodeling, nucleic acid binding, cell-cycle regulation, and cytoskeleton. Moreover, the putative roles of 16 proteins which have not been previously associated to meiosis or were not identified in rice before, are also discussed namely: seven proteins involved in chromosome structure and remodeling, five regulatory proteins [such as SKP1 (OSK), a putative CDK2 like effector], a protein with RNA recognition motifs, a neddylation-related protein, and two microtubule-related proteins. Revealing the proteins involved in early meiotic processes could provide a valuable tool kit to manipulate chromosome associations during meiosis in rice breeding programs. The data have been deposited to the ProteomeXchange with the PXD001058 identifier.
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Affiliation(s)
| | | | - Pilar Prieto
- *Correspondence: Pilar Prieto, Plant Breeding Department, Instituto de Agricultura Sostenible, Agencia Estatal Consejo Superior de Investigaciones Científicas, Av. Menéndez Pidal s/n, Campus Alameda del Obispo, Apartado 4084, Córdoba 14080, Spain e-mail:
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Merlet J, Pintard L. Role of the CRL2(LRR-1) E3 ubiquitin-ligase in the development of the germline in C. elegans. WORM 2013; 2:e25716. [PMID: 24778939 PMCID: PMC3875651 DOI: 10.4161/worm.25716] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Accepted: 07/10/2013] [Indexed: 01/16/2023]
Abstract
The ubiquitin-proteolytic system (UPS) regulates a variety of cellular and biological processes by controlling the stability of regulatory proteins, in space and time. Not surprisingly, defects in this system have been associated with various syndromes and pathologies, including cancer, illustrating the importance of understanding the regulation and the multiple functions of this system. C. elegans is a powerful model system to identify components of the UPS and to study their function during development in multicellular organisms. In C. elegans, the evolutionarily conserved CRL2LRR-1 E3-ligase is critical for the development of the germline. Inactivation of the CUL-2 scaffold or the LRR-1 substrate-recognition subunit leads to a cell cycle arrest in germline stem cells resulting in sterility. Through a genetic screen, we have identified a cul-2 temperature-sensitive allele and we have used this allele to show that CUL-2 plays multiple roles in the development of the germline. CUL-2 (1) promotes germ cell proliferation, (2) influences the balance between mitotic proliferation and meiotic differentiation, and (3) inhibits the first step of meiotic prophase. Here, we discuss how CUL-2 regulates and coordinates these different processes. We suggest that ubiquitin-mediated protein degradation constitutes an important additional layer of regulation that contributes to the spatial organization of the germline.
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Affiliation(s)
- Jorge Merlet
- Institut Jacques Monod; Monod; CNRS; UMR 7592; Univ. Paris Diderot; Sorbonne Paris Cité; F-75205 Paris, France
| | - Lionel Pintard
- Institut Jacques Monod; Monod; CNRS; UMR 7592; Univ. Paris Diderot; Sorbonne Paris Cité; F-75205 Paris, France
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