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Kim HJ, Liu C, Zhang L, Dernburg AF. MJL-1 is a nuclear envelope protein required for homologous chromosome pairing and regulation of synapsis during meiosis in C. elegans. SCIENCE ADVANCES 2023; 9:eadd1453. [PMID: 36753547 PMCID: PMC9908027 DOI: 10.1126/sciadv.add1453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Accepted: 01/06/2023] [Indexed: 06/18/2023]
Abstract
Interactions between chromosomes and LINC (linker of nucleoskeleton and cytoskeleton) complexes in the nuclear envelope (NE) promote homolog pairing and synapsis during meiosis. By tethering chromosomes to cytoskeletal motors, these connections lead to processive chromosome movements along the NE. This activity is usually mediated by telomeres, but in the nematode Caenorhabditis elegans, special chromosome regions called "pairing centers" (PCs) have acquired this meiotic function. Here, we identify a previously uncharacterized meiosis-specific NE protein, MJL-1 (MAJIN-Like-1), that is essential for interactions between PCs and LINC complexes in C. elegans. Mutations in MJL-1 eliminate active chromosome movements during meiosis, resulting in nonhomologous synapsis and impaired homolog pairing. Fission yeast and mice also require NE proteins to connect chromosomes to LINC complexes. Extensive similarities in the molecular architecture of meiotic chromosome-NE attachments across eukaryotes suggest a common origin and/or functions of this architecture during meiosis.
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Affiliation(s)
- Hyung Jun Kim
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3200, USA
| | - Chenshu Liu
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3200, USA
- Howard Hughes Medical Institute, 4000 Jones Bridge Road, Chevy Chase, MD 20815-6789, USA
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, Berkeley, CA 94720, USA
| | - Liangyu Zhang
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3200, USA
- Howard Hughes Medical Institute, 4000 Jones Bridge Road, Chevy Chase, MD 20815-6789, USA
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, Berkeley, CA 94720, USA
| | - Abby F. Dernburg
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3200, USA
- Howard Hughes Medical Institute, 4000 Jones Bridge Road, Chevy Chase, MD 20815-6789, USA
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, Berkeley, CA 94720, USA
- Biological Sciences and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
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2
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Zhang L, Stauffer WT, Wang JS, Wu F, Yu Z, Liu C, Kim HJ, Dernburg AF. Recruitment of Polo-like kinase couples synapsis to meiotic progression via inactivation of CHK-2. eLife 2023; 12:84492. [PMID: 36700544 PMCID: PMC9998088 DOI: 10.7554/elife.84492] [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: 10/26/2022] [Accepted: 01/25/2023] [Indexed: 01/27/2023] Open
Abstract
Meiotic chromosome segregation relies on synapsis and crossover (CO) recombination between homologous chromosomes. These processes require multiple steps that are coordinated by the meiotic cell cycle and monitored by surveillance mechanisms. In diverse species, failures in chromosome synapsis can trigger a cell cycle delay and/or lead to apoptosis. How this key step in 'homolog engagement' is sensed and transduced by meiotic cells is unknown. Here we report that in C. elegans, recruitment of the Polo-like kinase PLK-2 to the synaptonemal complex triggers phosphorylation and inactivation of CHK-2, an early meiotic kinase required for pairing, synapsis, and double-strand break (DSB) induction. Inactivation of CHK-2 terminates DSB formation and enables CO designation and cell cycle progression. These findings illuminate how meiotic cells ensure CO formation and accurate chromosome segregation.
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Affiliation(s)
- Liangyu Zhang
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
- California Institute for Quantitative BiosciencesBerkeleyUnited States
- Howard Hughes Medical InstituteChevy ChaseUnited States
- Biological Systems and Engineering Division, Lawrence Berkeley National LaboratoryBerkeleyUnited States
| | - Weston T Stauffer
- Howard Hughes Medical InstituteChevy ChaseUnited States
- Department of Integrative Biology, University of California, BerkeleyBerkeleyUnited States
| | - John S Wang
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
- Howard Hughes Medical InstituteChevy ChaseUnited States
| | - Fan Wu
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
- Howard Hughes Medical InstituteChevy ChaseUnited States
| | - Zhouliang Yu
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
- California Institute for Quantitative BiosciencesBerkeleyUnited States
- Howard Hughes Medical InstituteChevy ChaseUnited States
- Biological Systems and Engineering Division, Lawrence Berkeley National LaboratoryBerkeleyUnited States
| | - Chenshu Liu
- California Institute for Quantitative BiosciencesBerkeleyUnited States
- Howard Hughes Medical InstituteChevy ChaseUnited States
| | - Hyung Jun Kim
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Abby F Dernburg
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
- California Institute for Quantitative BiosciencesBerkeleyUnited States
- Howard Hughes Medical InstituteChevy ChaseUnited States
- Biological Systems and Engineering Division, Lawrence Berkeley National LaboratoryBerkeleyUnited States
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3
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Wang R, Hou Y, Geng G, Zhu X, Wang Z, Cai W, Ye J, Zhao S, Mi Y, Jiang J. Onvansertib inhibits the proliferation and improves the cisplatin-resistance of lung adenocarcinoma via β-catenin/c-Myc signaling pathway. Am J Cancer Res 2023; 13:623-637. [PMID: 36895968 PMCID: PMC9989612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 01/10/2023] [Indexed: 03/11/2023] Open
Abstract
Polo-like kinase 1 (PLK1) is a key regulator of cell division, and its abnormal expression is related to the progression and prognosis of cancers. However, the effect of PLK1 inhibitor onvansertib on the growth of lung adenocarcinoma (LUAD) has not been explored. In this study, we performed a series of bioinformatics and experimental analyses to comprehensively investigate the role of PLK1 in LUAD. We used CCK-8 assay and colony formation assay to evaluate the growth inhibitory ability of onvansertib. Furthermore, flow cytometry was applied to exploit the effects of onvansertib on cell cycle, apoptosis, and mitochondrial membrane potential. Moreover, the therapeutic potential of onvansertib was assessed in vivo by using xenograft tumor and patient-derived xenograft (PDX) models. We found that onvansertib significantly induced the apoptosis and inhibited the proliferation and migration of LUAD cells. Mechanistically, onvansertib arrested the cells at G2/M phase and enhanced the levels of reactive oxidative species in LUAD. Accordingly, onvansertib regulated the expression of glycolysis-related genes and improved the cisplatin resistance in LUAD. Notably, the protein levels of β-catenin and c-Myc were affected by onvansertib. Taken together, our findings provide insight into the function of onvansertib and shed light on the potential clinical application of onvansertib for the treatment of patients with LUAD.
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Affiliation(s)
- Rong Wang
- Medical College, Guangxi University Nanning, Guangxi, P.R. China
| | - Yihan Hou
- Department of Medical Oncology, Xiamen Key Laboratory of Antitumor Drug Transformation Research, The First Affiliated Hospital of Xiamen University, School of Clinical Medicine, Xiamen University Xiamen 361003, Fujian Province, P.R. China
| | - Guojun Geng
- Department of Thoracic Surgery, Xiamen Key Laboratory of Thoracic Tumor Diagnosis and Treatment, Institute of Lung Cancer, The First Affiliated Hospital of Xiamen University, School of Clinical Medicine, Xiamen University Xiamen 361003, Fujian Province, P.R. China
| | - Xiaolei Zhu
- Department of Thoracic Surgery, Xiamen Key Laboratory of Thoracic Tumor Diagnosis and Treatment, Institute of Lung Cancer, The First Affiliated Hospital of Xiamen University, School of Clinical Medicine, Xiamen University Xiamen 361003, Fujian Province, P.R. China
| | - Zhilin Wang
- Department of Thoracic Surgery, Xiamen Key Laboratory of Thoracic Tumor Diagnosis and Treatment, Institute of Lung Cancer, The First Affiliated Hospital of Xiamen University, School of Clinical Medicine, Xiamen University Xiamen 361003, Fujian Province, P.R. China
| | - Weifeng Cai
- Department of Thoracic Surgery, Xiamen Key Laboratory of Thoracic Tumor Diagnosis and Treatment, Institute of Lung Cancer, The First Affiliated Hospital of Xiamen University, School of Clinical Medicine, Xiamen University Xiamen 361003, Fujian Province, P.R. China
| | - Juanping Ye
- Department of Medical Oncology, Xiamen Key Laboratory of Antitumor Drug Transformation Research, The First Affiliated Hospital of Xiamen University, School of Clinical Medicine, Xiamen University Xiamen 361003, Fujian Province, P.R. China
| | - Senxia Zhao
- Department of Medical Oncology, Xiamen Key Laboratory of Antitumor Drug Transformation Research, The First Affiliated Hospital of Xiamen University, School of Clinical Medicine, Xiamen University Xiamen 361003, Fujian Province, P.R. China
| | - Yanjun Mi
- Department of Medical Oncology, Xiamen Key Laboratory of Antitumor Drug Transformation Research, The First Affiliated Hospital of Xiamen University, School of Clinical Medicine, Xiamen University Xiamen 361003, Fujian Province, P.R. China
| | - Jie Jiang
- Department of Thoracic Surgery, Xiamen Key Laboratory of Thoracic Tumor Diagnosis and Treatment, Institute of Lung Cancer, The First Affiliated Hospital of Xiamen University, School of Clinical Medicine, Xiamen University Xiamen 361003, Fujian Province, P.R. China
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4
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Palacios-Blanco I, Martín-Castellanos C. Cyclins and CDKs in the regulation of meiosis-specific events. Front Cell Dev Biol 2022; 10:1069064. [PMID: 36523509 PMCID: PMC9745066 DOI: 10.3389/fcell.2022.1069064] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 11/14/2022] [Indexed: 07/13/2024] Open
Abstract
How eukaryotic cells control their duplication is a fascinating example of how a biological system self-organizes specific activities to temporally order cellular events. During cell cycle progression, the cellular level of CDK (Cyclin-Dependent Kinase) activity temporally orders the different cell cycle phases, ensuring that DNA replication occurs prior to segregation into two daughter cells. CDK activity requires the binding of a regulatory subunit (cyclin) to the core kinase, and both CDKs and cyclins are well conserved throughout evolution from yeast to humans. As key regulators, they coordinate cell cycle progression with metabolism, DNA damage, and cell differentiation. In meiosis, the special cell division that ensures the transmission of genetic information from one generation to the next, cyclins and CDKs have acquired novel functions to coordinate meiosis-specific events such as chromosome architecture, recombination, and synapsis. Interestingly, meiosis-specific cyclins and CDKs are common in evolution, some cyclins seem to have evolved to acquire CDK-independent functions, and even some CDKs associate with a non-cyclin partner. We will review the functions of these key regulators in meiosis where variation has specially flourished.
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Rosa BA, Curtis K, Erdmann Gilmore P, Martin J, Zhang Q, Sprung R, Weil GJ, Townsend RR, Fischer PU, Mitreva M. Direct Proteomic Detection and Prioritization of 19 Onchocerciasis Biomarker Candidates in Humans. Mol Cell Proteomics 2022; 22:100454. [PMID: 36435333 PMCID: PMC9792368 DOI: 10.1016/j.mcpro.2022.100454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 10/30/2022] [Accepted: 11/21/2022] [Indexed: 11/24/2022] Open
Abstract
Onchocerca volvulus, the causative agent of onchocerciasis, infects over 20 million people and can cause severe dermatitis and ocular conditions including blindness. Current treatments employed in mass drug administration programs do not kill adult female worms, and common diagnostic tests cannot reliably assess viability of adult worms. There is an urgent need for better diagnostic tests to facilitate monitoring the efficacy of new treatments and disease elimination efforts. Here, eight plasma samples collected from individuals infected with O. volvulus and seven from uninfected individuals were analyzed by MS/MS spectrometry to directly identify O. volvulus proteins present in infected but absent in uninfected control samples. This direct proteomic approach for biomarker discovery had not been previously employed for onchocerciasis. Among all detected proteins, 19 biomarker candidates were supported by two or more unique peptides, identified in the plasma of at least three O. volvulus-infected human samples and absent in all control samples. Comprehensive analysis and ranking of these candidates included detailed functional annotation and a review of RNA-seq gene expression profiles. Isotope-labeled standard peptides were run in parallel and validated MS/MS peptide identifications for 15 peptides from 11 of the 19 proteins, and two infected urine and one uninfected urine sample was used for additional validation. A major antigen/OVOC11613 was identified as the most promising candidate with eight unique peptides across five plasma samples and one urine sample. Additional strong candidates included OVOC1523/ATP synthase, OVOC247/laminin and OVOC11626/PLK5, and along with OVOC11613, and were also detected in urine samples from onchocerciasis patients. This study has identified a promising novel set of proteins that will be carried forward to develop assays that can be used for diagnosis of O. volvulus infections and for monitoring treatment efficacy.
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Affiliation(s)
- Bruce A. Rosa
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - Kurt Curtis
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - Petra Erdmann Gilmore
- Division of Endocrinology, Metabolism and Lipid Research, Department of Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - John Martin
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - Qiang Zhang
- Division of Endocrinology, Metabolism and Lipid Research, Department of Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - Robert Sprung
- Division of Endocrinology, Metabolism and Lipid Research, Department of Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - Gary J. Weil
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - R. Reid Townsend
- Division of Endocrinology, Metabolism and Lipid Research, Department of Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - Peter U. Fischer
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - Makedonka Mitreva
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St Louis, Missouri, USA,Department of Genetics, Washington University School of Medicine, St Louis, Missouri, USA,McDonnell Genome Institute, Washington University School of Medicine, St Louis, Missouri, USA,For correspondence: Makedonka Mitreva
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6
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Das D, Trivedi S, Blazícková J, Arur S, Silva N. Phosphorylation of HORMA-domain protein HTP-3 at Serine 285 is dispensable for crossover formation. G3 (BETHESDA, MD.) 2022; 12:jkac079. [PMID: 35389463 PMCID: PMC9073698 DOI: 10.1093/g3journal/jkac079] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Accepted: 03/31/2022] [Indexed: 11/30/2022]
Abstract
Generation of functional gametes is accomplished through a multilayered and finely orchestrated succession of events during meiotic progression. In the Caenorhabditis elegans germline, the HORMA-domain-containing protein HTP-3 plays pivotal roles for the establishment of chromosome axes and the efficient induction of programmed DNA double-strand breaks, both of which are crucial for crossover formation. Double-strand breaks allow for accurate chromosome segregation during the first meiotic division and therefore are an essential requirement for the production of healthy gametes. Phosphorylation-dependent regulation of HORMAD protein plays important roles in controlling meiotic chromosome behavior. Here, we document a phospho-site in HTP-3 at Serine 285 that is constitutively phosphorylated during meiotic prophase I. pHTP-3S285 localization overlaps with panHTP-3 except in nuclei undergoing physiological apoptosis, in which pHTP-3 is absent. Surprisingly, we observed that phosphorylation of HTP-3 at S285 is independent of the canonical kinases that control meiotic progression in nematodes. During meiosis, the htp-3(S285A) mutant displays accelerated RAD-51 turnover, but no other meiotic abnormalities. Altogether, these data indicate that the Ser285 phosphorylation is independent of canonical meiotic protein kinases and does not regulate HTP-3-dependent meiotic processes. We propose a model wherein phosphorylation of HTP-3 occurs through noncanonical or redundant meiotic kinases and/or is likely redundant with additional phospho-sites for function in vivo.
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Affiliation(s)
- Debabrata Das
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Shalini Trivedi
- Department of Biology, Faculty of Medicine, Masaryk University, 62500 Brno, Czech Republic
| | - Jitka Blazícková
- Department of Biology, Faculty of Medicine, Masaryk University, 62500 Brno, Czech Republic
| | - Swathi Arur
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Nicola Silva
- Department of Biology, Faculty of Medicine, Masaryk University, 62500 Brno, Czech Republic
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7
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Wellard SR, Skinner MW, Zhao X, Shults C, Jordan PW. PLK1 depletion alters homologous recombination and synaptonemal complex disassembly events during mammalian spermatogenesis. Mol Biol Cell 2022; 33:ar37. [PMID: 35274968 PMCID: PMC9282006 DOI: 10.1091/mbc.e21-03-0115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 02/25/2022] [Accepted: 03/03/2022] [Indexed: 11/11/2022] Open
Abstract
Homologous recombination (HR) is an essential meiotic process that contributes to the genetic variation of offspring and ensures accurate chromosome segregation. Recombination is facilitated by the formation and repair of programmed DNA double-strand breaks. These DNA breaks are repaired via recombination between maternal and paternal homologous chromosomes and a subset result in the formation of crossovers. HR and crossover formation is facilitated by synapsis of homologous chromosomes by a proteinaceous scaffold structure known as the synaptonemal complex (SC). Recent studies in yeast and worms have indicated that polo-like kinases (PLKs) regulate several events during meiosis, including DNA recombination and SC dynamics. Mammals express four active PLKs (PLK1-4), and our previous work assessing localization and kinase function in mouse spermatocytes suggested that PLK1 coordinates nuclear events during meiotic prophase. Therefore, we conditionally mutated Plk1 in early prophase spermatocytes and assessed stages of HR, crossover formation, and SC processes. Plk1 mutation resulted in increased RPA foci and reduced RAD51/DMC1 foci during zygonema, and an increase of both class I and class II crossover events. Furthermore, the disassembly of SC lateral elements was aberrant. Our results highlight the importance of PLK1 in regulating HR and SC disassembly during spermatogenesis.
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Affiliation(s)
- Stephen R. Wellard
- Biochemistry and Molecular Biology Department, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205
| | - Marnie W. Skinner
- Biochemistry and Molecular Biology Department, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205
| | - Xueqi Zhao
- Biochemistry and Molecular Biology Department, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205
| | - Chris Shults
- Biochemistry and Molecular Biology Department, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205
| | - Philip W. Jordan
- Biochemistry and Molecular Biology Department, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205
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8
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Wenda JM, Prosée RF, Gabus C, Steiner FA. Mitotic chromosome condensation requires phosphorylation of the centromeric protein KNL-2 in C. elegans. J Cell Sci 2021; 134:272713. [PMID: 34734636 PMCID: PMC8714079 DOI: 10.1242/jcs.259088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 10/25/2021] [Indexed: 11/20/2022] Open
Abstract
Centromeres are chromosomal regions that serve as sites for kinetochore formation and microtubule attachment, processes that are essential for chromosome segregation during mitosis. Centromeres are almost universally defined by the histone variant CENP-A. In the holocentric nematode C. elegans, CENP-A deposition depends on the loading factor KNL-2. Depletion of either CENP-A or KNL-2 results in defects in centromere maintenance, chromosome condensation and kinetochore formation, leading to chromosome segregation failure. Here, we show that KNL-2 is phosphorylated by CDK-1 in vitro, and that mutation of three C-terminal phosphorylation sites causes chromosome segregation defects and an increase in embryonic lethality. In strains expressing phosphodeficient KNL-2, CENP-A and kinetochore proteins are properly localised, indicating that the role of KNL-2 in centromere maintenance is not affected. Instead, the mutant embryos exhibit reduced mitotic levels of condensin II on chromosomes and significant chromosome condensation impairment. Our findings separate the functions of KNL-2 in CENP-A loading and chromosome condensation, and demonstrate that KNL-2 phosphorylation regulates the cooperation between centromeric regions and the condensation machinery in C. elegans. This article has an associated First Person interview with the first author of the paper. Summary: Phosphorylation of the essential centromere protein KNL-2 is required for mitotic chromosome condensation, but not for the role of KNL-2 in centromere maintenance and kinetochore formation.
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Affiliation(s)
- Joanna M Wenda
- Department of Molecular Biology and Institute for Genetics and Genomics in Geneva, Section of Biology, Faculty of Sciences, University of Geneva, 1211 Geneva, Switzerland
| | - Reinier F Prosée
- Department of Molecular Biology and Institute for Genetics and Genomics in Geneva, Section of Biology, Faculty of Sciences, University of Geneva, 1211 Geneva, Switzerland
| | - Caroline Gabus
- Department of Molecular Biology and Institute for Genetics and Genomics in Geneva, Section of Biology, Faculty of Sciences, University of Geneva, 1211 Geneva, Switzerland
| | - Florian A Steiner
- Department of Molecular Biology and Institute for Genetics and Genomics in Geneva, Section of Biology, Faculty of Sciences, University of Geneva, 1211 Geneva, Switzerland
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Abstract
A central player in meiotic chromosome dynamics is the conserved Polo-like kinase (PLK) family. PLKs are dynamically localized to distinct structures during meiotic prophase and phosphorylate a diverse group of substrates to control homolog pairing, synapsis, and meiotic recombination. In a recent study, we uncovered the mechanisms that control the targeting of a meiosis-specific PLK-2 in C. elegans. In early meiotic prophase, PLK-2 localizes to special chromosome regions known as pairing centers and drives homolog pairing and synapsis. PLK-2 then relocates to the synaptonemal complex (SC) after crossover designation and mediates chromosome remodeling required for homolog separation. What controls this intricate targeting of PLK-2 in space and time? We discuss recent findings and remaining questions for the future.
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Affiliation(s)
| | - Yumi Kim
- Department of Biology, Johns Hopkins University, Baltimore, MD
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HIM-17 regulates the position of recombination events and GSP-1/2 localization to establish short arm identity on bivalents in meiosis. Proc Natl Acad Sci U S A 2021; 118:2016363118. [PMID: 33883277 DOI: 10.1073/pnas.2016363118] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The position of recombination events established along chromosomes in early prophase I and the chromosome remodeling that takes place in late prophase I are intrinsically linked steps of meiosis that need to be tightly regulated to ensure accurate chromosome segregation and haploid gamete formation. Here, we show that RAD-51 foci, which form at the sites of programmed meiotic DNA double-strand breaks (DSBs), exhibit a biased distribution toward off-centered positions along the chromosomes in wild-type Caenorhabditis elegans, and we identify two meiotic roles for chromatin-associated protein HIM-17 that ensure normal chromosome remodeling in late prophase I. During early prophase I, HIM-17 regulates the distribution of DSB-dependent RAD-51 foci and crossovers on chromosomes, which is critical for the formation of distinct chromosome subdomains (short and long arms of the bivalents) later during chromosome remodeling. During late prophase I, HIM-17 promotes the normal expression and localization of protein phosphatases GSP-1/2 to the surface of the bivalent chromosomes and may promote GSP-1 phosphorylation, thereby antagonizing Aurora B kinase AIR-2 loading on the long arms and preventing premature loss of sister chromatid cohesion. We propose that HIM-17 plays distinct roles at different stages during meiotic progression that converge to promote normal chromosome remodeling and accurate chromosome segregation.
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11
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Kar FM, Hochwagen A. Phospho-Regulation of Meiotic Prophase. Front Cell Dev Biol 2021; 9:667073. [PMID: 33928091 PMCID: PMC8076904 DOI: 10.3389/fcell.2021.667073] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 03/22/2021] [Indexed: 12/12/2022] Open
Abstract
Germ cells undergoing meiosis rely on an intricate network of surveillance mechanisms that govern the production of euploid gametes for successful sexual reproduction. These surveillance mechanisms are particularly crucial during meiotic prophase, when cells execute a highly orchestrated program of chromosome morphogenesis and recombination, which must be integrated with the meiotic cell division machinery to ensure the safe execution of meiosis. Dynamic protein phosphorylation, controlled by kinases and phosphatases, has emerged as one of the main signaling routes for providing readout and regulation of chromosomal and cellular behavior throughout meiotic prophase. In this review, we discuss common principles and provide detailed examples of how these phosphorylation events are employed to ensure faithful passage of chromosomes from one generation to the next.
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Affiliation(s)
- Funda M Kar
- Department of Biology, New York University, New York, NY, United States
| | - Andreas Hochwagen
- Department of Biology, New York University, New York, NY, United States
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