1
|
Gong T, McNally KL, Konanoor S, Peraza A, Bailey C, Redemann S, McNally FJ. Roles of Tubulin Concentration during Prometaphase and Ran-GTP during Anaphase of Caenorhabditis elegans Meiosis. Life Sci Alliance 2024; 7:e202402884. [PMID: 38960623 PMCID: PMC11222656 DOI: 10.26508/lsa.202402884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2024] [Revised: 06/25/2024] [Accepted: 06/26/2024] [Indexed: 07/05/2024] Open
Abstract
In many animal species, the oocyte meiotic spindle, which is required for chromosome segregation, forms without centrosomes. In some systems, Ran-GEF on chromatin initiates spindle assembly. We found that in Caenorhabditis elegans oocytes, endogenously-tagged Ran-GEF dissociates from chromatin during spindle assembly but re-associates during meiotic anaphase. Meiotic spindle assembly occurred after auxin-induced degradation of Ran-GEF, but anaphase I was faster than controls and extrusion of the first polar body frequently failed. In search of a possible alternative pathway for spindle assembly, we found that soluble tubulin concentrates in the nuclear volume during germinal vesicle breakdown. We found that the concentration of soluble tubulin in the metaphase spindle region is enclosed by ER sheets which exclude cytoplasmic organelles including mitochondria and yolk granules. Measurement of the volume occupied by yolk granules and mitochondria indicated that volume exclusion would be sufficient to explain the concentration of tubulin in the spindle volume. We suggest that this concentration of soluble tubulin may be a redundant mechanism promoting spindle assembly near chromosomes.
Collapse
Affiliation(s)
- Ting Gong
- https://ror.org/05rrcem69 Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA, USA
| | - Karen L McNally
- https://ror.org/05rrcem69 Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA, USA
| | - Siri Konanoor
- https://ror.org/05rrcem69 Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA, USA
| | - Alma Peraza
- https://ror.org/05rrcem69 Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA, USA
| | - Cynthia Bailey
- https://ror.org/05rrcem69 Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA, USA
| | - Stefanie Redemann
- https://ror.org/0153tk833 Department of Cell Biology, University of Virginia, School of Medicine, Charlottesville, VA, USA
| | - Francis J McNally
- https://ror.org/05rrcem69 Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA, USA
| |
Collapse
|
2
|
McNally K, McNally F. Auxin-induced degradation of the aurora A kinase, AIR-1, in C. elegans does not prevent assembly of bipolar meiotic spindles. MICROPUBLICATION BIOLOGY 2024; 2024:10.17912/micropub.biology.001123. [PMID: 38362120 PMCID: PMC10867633 DOI: 10.17912/micropub.biology.001123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 01/29/2024] [Accepted: 01/31/2024] [Indexed: 02/17/2024]
Abstract
Chromosome segregation during mitosis and male meiosis is mediated by centrosomal spindles that require the activity of the aurora A kinase, whereas female meiotic spindles of many species are acentrosomal. We addressed the role of the C. elegans aurora A kinase, AIR-1 , in acentrosomal spindle assembly by generating a strain in which AIR-1 is tagged with both an auxin-induced degron and HALO tag. The meiotic spindle pole marker, MEI-1 , and chromosomes were labeled with GFP and mCH::histone respectively. All meiotic spindles were bipolar in AIR-1 depleted embryos, however an increase in lagging chromosomes was observed during anaphase.
Collapse
Affiliation(s)
- Karen McNally
- Molecular and Cellular Biology, University of California, Davis, Davis, California, United States
| | - Francis McNally
- Molecular and Cellular Biology, University of California, Davis, Davis, California, United States
| |
Collapse
|
3
|
Li W, Crellin HA, Cheerambathur D, McNally FJ. Redundant microtubule crosslinkers prevent meiotic spindle bending to ensure diploid offspring in C. elegans. PLoS Genet 2023; 19:e1011090. [PMID: 38150489 PMCID: PMC10775986 DOI: 10.1371/journal.pgen.1011090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 01/09/2024] [Accepted: 12/05/2023] [Indexed: 12/29/2023] Open
Abstract
Oocyte meiotic spindles mediate the expulsion of ¾ of the genome into polar bodies to generate diploid zygotes in nearly all animal species. Failures in this process result in aneuploid or polyploid offspring that are typically inviable. Accurate meiotic chromosome segregation and polar body extrusion require the spindle to elongate while maintaining its structural integrity. Previous studies have implicated three hypothetical activities during this process, including microtubule crosslinking, microtubule sliding and microtubule polymerization. However, how these activities regulate spindle rigidity and elongation as well as the exact proteins involved in the activities remain unclear. We discovered that C. elegans meiotic anaphase spindle integrity is maintained through redundant microtubule crosslinking activities of the Kinesin-5 family motor BMK-1, the microtubule bundling protein SPD-1/PRC1, and the Kinesin-4 family motor, KLP-19. Using time-lapse imaging, we found that single depletion of KLP-19KIF4A, SPD-1PRC1 or BMK-1Eg5 had minimal effects on anaphase B spindle elongation velocity. In contrast, double depletion of SPD-1PRC1 and BMK-1Eg5 or double depletion of KLP-19KIF4A and BMK-1Eg5 resulted in spindles that elongated faster, bent in a myosin-dependent manner, and had a high rate of polar body extrusion errors. Bending spindles frequently extruded both sets of segregating chromosomes into two separate polar bodies. Normal anaphase B velocity was observed after double depletion of KLP-19KIF4A and SPD-1PRC1. These results suggest that KLP-19KIF4A and SPD-1PRC1 act in different pathways, each redundant with a separate BMK-1Eg5 pathway in regulating meiotic spindle elongation. Depletion of ZYG-8, a doublecortin-related microtubule binding protein, led to slower anaphase B spindle elongation. We found that ZYG-8DCLK1 acts by excluding SPD-1PRC1 from the spindle. Thus, three mechanistically distinct microtubule regulation modules, two based on crosslinking, and one based on exclusion of crosslinkers, power the mechanism that drives spindle elongation and structural integrity during anaphase B of C.elegans female meiosis.
Collapse
Affiliation(s)
- Wenzhe Li
- Department of Molecular and Cellular Biology, University of California, Davis, California, United States of America
| | - Helena A. Crellin
- Wellcome Centre for Cell Biology & Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Dhanya Cheerambathur
- Wellcome Centre for Cell Biology & Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Francis J. McNally
- Department of Molecular and Cellular Biology, University of California, Davis, California, United States of America
| |
Collapse
|
4
|
Quiogue AR, Sumiyoshi E, Fries A, Chuang CH, Bowerman B. Microtubules oppose cortical actomyosin-driven membrane ingression during C. elegans meiosis I polar body extrusion. PLoS Genet 2023; 19:e1010984. [PMID: 37782660 PMCID: PMC10569601 DOI: 10.1371/journal.pgen.1010984] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 10/12/2023] [Accepted: 09/19/2023] [Indexed: 10/04/2023] Open
Abstract
During C. elegans oocyte meiosis I cytokinesis and polar body extrusion, cortical actomyosin is locally remodeled to assemble a contractile ring that forms within and remains part of a much larger and actively contractile cortical actomyosin network. This network both mediates contractile ring dynamics and generates shallow ingressions throughout the oocyte cortex during polar body extrusion. Based on our analysis of requirements for CLS-2, a member of the CLASP family of proteins that stabilize microtubules, we recently proposed that a balance of actomyosin-mediated tension and microtubule-mediated stiffness limits membrane ingression throughout the oocyte during meiosis I polar body extrusion. Here, using live cell imaging and fluorescent protein fusions, we show that CLS-2 is part of a group of kinetochore proteins, including the scaffold KNL-1 and the kinase BUB-1, that also co-localize during meiosis I to structures called linear elements, which are present within the assembling oocyte spindle and also are distributed throughout the oocyte in proximity to, but appearing to underlie, the actomyosin cortex. We further show that KNL-1 and BUB-1, like CLS-2, promote the proper organization of sub-cortical microtubules and also limit membrane ingression throughout the oocyte. Moreover, nocodazole or taxol treatment to destabilize or stabilize oocyte microtubules leads to, respectively, excess or decreased membrane ingression throughout the oocyte. Furthermore, taxol treatment, and genetic backgrounds that elevate the levels of cortically associated microtubules, both suppress excess membrane ingression in cls-2 mutant oocytes. We propose that linear elements influence the organization of sub-cortical microtubules to generate a stiffness that limits cortical actomyosin-driven membrane ingression throughout the oocyte during meiosis I polar body extrusion. We discuss the possibility that this regulation of sub-cortical microtubule dynamics facilitates actomyosin contractile ring dynamics during C. elegans oocyte meiosis I cell division.
Collapse
Affiliation(s)
- Alyssa R. Quiogue
- Institute of Molecular Biology, University of Oregon, Eugen, Oregon, United States of America
| | - Eisuke Sumiyoshi
- Institute of Molecular Biology, University of Oregon, Eugen, Oregon, United States of America
| | - Adam Fries
- Institute of Molecular Biology, University of Oregon, Eugen, Oregon, United States of America
- Imaging Core, Office of the Vice President for Research University of Oregon, Eugene, Oregon, United States of America
| | - Chien-Hui Chuang
- Institute of Molecular Biology, University of Oregon, Eugen, Oregon, United States of America
| | - Bruce Bowerman
- Institute of Molecular Biology, University of Oregon, Eugen, Oregon, United States of America
| |
Collapse
|
5
|
Quiogue AR, Sumiyoshi E, Fries A, Chuang CH, Bowerman B. Cortical microtubules oppose actomyosin-driven membrane ingression during C. elegans meiosis I polar body extrusion. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.26.542508. [PMID: 37292632 PMCID: PMC10245968 DOI: 10.1101/2023.05.26.542508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
During C. elegans oocyte meiosis I, cortical actomyosin is locally remodeled to assemble a contractile ring near the spindle. In contrast to mitosis, when most cortical actomyosin converges into a contractile ring, the small oocyte ring forms within and remains part of a much larger and actively contractile cortical actomyosin network. This network both mediates contractile ring dynamics and generates shallow ingressions throughout the oocyte cortex during polar body extrusion. Based on our analysis of requirements for CLS-2, a member of the CLASP family of proteins that stabilize microtubules, we recently proposed that a balance of actomyosin-mediated tension and microtubule-mediated stiffness are required for contractile ring assembly within the oocyte cortical actomyosin network. Here, using live cell imaging and fluorescent protein fusions, we show that CLS-2 is part of a complex of kinetochore proteins, including the scaffold KNL-1 and the kinase BUB-1, that also co-localize to patches distributed throughout the oocyte cortex during meiosis I. By reducing their function, we further show that KNL-1 and BUB-1, like CLS-2, are required for cortical microtubule stability, to limit membrane ingression throughout the oocyte, and for meiotic contractile ring assembly and polar body extrusion. Moreover, nocodazole or taxol treatment to destabilize or stabilize oocyte microtubules, respectively, leads to excess or decreased membrane ingression throughout the oocyte and defective polar body extrusion. Finally, genetic backgrounds that elevate cortical microtubule levels suppress the excess membrane ingression in cls-2 mutant oocytes. These results support our hypothesis that CLS-2, as part of a sub-complex of kinetochore proteins that also co-localize to patches throughout the oocyte cortex, stabilizes microtubules to stiffen the oocyte cortex and limit membrane ingression throughout the oocyte, thereby facilitating contractile ring dynamics and the successful completion of polar body extrusion during meiosis I.
Collapse
Affiliation(s)
| | | | - Adam Fries
- Institute of Molecular Biology
- Imaging Core, Office of the Vice President for Research, University of Oregon, Eugene, OR USA 97403
| | | | | |
Collapse
|
6
|
Macaisne N, Bellutti L, Laband K, Edwards F, Pitayu-Nugroho L, Gervais A, Ganeswaran T, Geoffroy H, Maton G, Canman JC, Lacroix B, Dumont J. Synergistic stabilization of microtubules by BUB-1, HCP-1, and CLS-2 controls microtubule pausing and meiotic spindle assembly. eLife 2023; 12:e82579. [PMID: 36799894 PMCID: PMC10005782 DOI: 10.7554/elife.82579] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 02/16/2023] [Indexed: 02/18/2023] Open
Abstract
During cell division, chromosome segregation is orchestrated by a microtubule-based spindle. Interaction between spindle microtubules and kinetochores is central to the bi-orientation of chromosomes. Initially dynamic to allow spindle assembly and kinetochore attachments, which is essential for chromosome alignment, microtubules are eventually stabilized for efficient segregation of sister chromatids and homologous chromosomes during mitosis and meiosis I, respectively. Therefore, the precise control of microtubule dynamics is of utmost importance during mitosis and meiosis. Here, we study the assembly and role of a kinetochore module, comprised of the kinase BUB-1, the two redundant CENP-F orthologs HCP-1/2, and the CLASP family member CLS-2 (hereafter termed the BHC module), in the control of microtubule dynamics in Caenorhabditis elegans oocytes. Using a combination of in vivo structure-function analyses of BHC components and in vitro microtubule-based assays, we show that BHC components stabilize microtubules, which is essential for meiotic spindle formation and accurate chromosome segregation. Overall, our results show that BUB-1 and HCP-1/2 do not only act as targeting components for CLS-2 at kinetochores, but also synergistically control kinetochore-microtubule dynamics by promoting microtubule pause. Together, our results suggest that BUB-1 and HCP-1/2 actively participate in the control of kinetochore-microtubule dynamics in the context of an intact BHC module to promote spindle assembly and accurate chromosome segregation in meiosis.
Collapse
Affiliation(s)
- Nicolas Macaisne
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013ParisFrance
| | - Laura Bellutti
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013ParisFrance
| | - Kimberley Laband
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013ParisFrance
| | - Frances Edwards
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013ParisFrance
| | | | - Alison Gervais
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013ParisFrance
| | | | - Hélène Geoffroy
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013ParisFrance
| | - Gilliane Maton
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013ParisFrance
| | - Julie C Canman
- Columbia University; Department of Pathology and Cell BiologyNew YorkUnited States
| | - Benjamin Lacroix
- Centre de Recherche en Biologie Cellulaire de Montpellier (CRBM), CNRS UMR 5237, Université de MontpellierMontpellierFrance
| | - Julien Dumont
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013ParisFrance
| |
Collapse
|
7
|
Harvey AM, Chuang CH, Sumiyoshi E, Bowerman B. C. elegans XMAP215/ZYG-9 and TACC/TAC-1 act at multiple times during oocyte meiotic spindle assembly and promote both spindle pole coalescence and stability. PLoS Genet 2023; 19:e1010363. [PMID: 36608115 PMCID: PMC9851561 DOI: 10.1371/journal.pgen.1010363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 01/19/2023] [Accepted: 12/13/2022] [Indexed: 01/09/2023] Open
Abstract
The conserved two-component XMAP215/TACC modulator of microtubule stability is required in multiple animal phyla for acentrosomal spindle assembly during oocyte meiotic cell division. In C. elegans, XMAP215/zyg-9 and TACC/tac-1 mutant oocytes exhibit multiple and indistinguishable oocyte spindle assembly defects beginning early in meiosis I. To determine if these defects represent one or more early requirements with additional later and indirect consequences, or multiple temporally distinct and more direct requirements, we have used live cell imaging and fast-acting temperature-sensitive zyg-9 and tac-1 alleles to dissect their requirements at high temporal resolution. Temperature upshift and downshift experiments indicate that the ZYG-9/TAC-1 complex has multiple temporally distinct and separable requirements throughout oocyte meiotic cell division. First, we show that during prometaphase ZYG-9 and TAC-1 promote the coalescence of early pole foci into a bipolar structure, stabilizing pole foci as they grow and limiting their growth rate, with these requirements being independent of an earlier defect in microtubule organization that occurs upon nuclear envelope breakdown. Second, during metaphase, ZYG-9 and TAC-1 maintain spindle bipolarity by suppressing ectopic pole formation. Third, we show that ZYG-9 and TAC-1 also are required for spindle assembly during meiosis II, independently of their meiosis I requirements. The metaphase pole stability requirement appears to be important for maintaining chromosome congression, and we discuss how negative regulation of microtubule stability by ZYG-9/TAC-1 during oocyte meiotic cell division might account for the observed defects in spindle pole coalescence and stability.
Collapse
Affiliation(s)
- Austin M. Harvey
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon, United States of America
| | - Chien-Hui Chuang
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon, United States of America
| | - Eisuke Sumiyoshi
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon, United States of America
| | - Bruce Bowerman
- Institute of Molecular Biology, University of Oregon, Eugene, Oregon, United States of America
| |
Collapse
|
8
|
Cohesin is required for meiotic spindle assembly independent of its role in cohesion in C. elegans. PLoS Genet 2022; 18:e1010136. [PMID: 36279281 PMCID: PMC9632809 DOI: 10.1371/journal.pgen.1010136] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 11/03/2022] [Accepted: 10/10/2022] [Indexed: 11/06/2022] Open
Abstract
Accurate chromosome segregation requires a cohesin-mediated physical attachment between chromosomes that are to be segregated apart, and a bipolar spindle with microtubule plus ends emanating from exactly two poles toward the paired chromosomes. We asked whether the striking bipolar structure of C. elegans meiotic chromosomes is required for bipolarity of acentriolar female meiotic spindles by time-lapse imaging of mutants that lack cohesion between chromosomes. Both a spo-11 rec-8 coh-4 coh-3 quadruple mutant and a spo-11 rec-8 double mutant entered M phase with separated sister chromatids lacking any cohesion. However, the quadruple mutant formed an apolar spindle whereas the double mutant formed a bipolar spindle that segregated chromatids into two roughly equal masses. Residual non-cohesive COH-3/4-dependent cohesin on separated sister chromatids of the double mutant was sufficient to recruit haspin-dependent Aurora B kinase, which mediated bipolar spindle assembly in the apparent absence of chromosomal bipolarity. We hypothesized that cohesin-dependent Aurora B might activate or inhibit spindle assembly factors in a manner that would affect their localization on chromosomes and found that the chromosomal localization patterns of KLP-7 and CLS-2 correlated with Aurora B loading on chromosomes. These results demonstrate that cohesin is essential for spindle assembly and chromosome segregation independent of its role in sister chromatid cohesion.
Collapse
|
9
|
Lu T, Smit RB, Soueid H, Mains PE. STRIPAK regulation of katanin microtubule severing in the Caenorhabditis elegans embryo. Genetics 2022; 221:iyac043. [PMID: 35298637 PMCID: PMC9071564 DOI: 10.1093/genetics/iyac043] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 03/15/2022] [Indexed: 11/14/2022] Open
Abstract
Microtubule severing plays important role in cell structure and cell division. The microtubule severing protein katanin, composed of the MEI-1/MEI-2 subunits in Caenorhabditis elegans, is required for oocyte meiotic spindle formation; however, it must be inactivated for mitosis to proceed as continued katanin expression is lethal. Katanin activity is regulated by 2 ubiquitin-based protein degradation pathways. Another ubiquitin ligase, HECD-1, the homolog of human HECTD1/HECT domain E3 ubiquitin protein ligase 1, regulates katanin activity without affecting katanin levels. In other organisms, HECD-1 is a component of the striatin-interacting kinase phosphatase complex, which affects cell proliferation and a variety of signaling pathways. Here we conducted a systematic screen of how mutations in striatin-interacting kinase phosphatase components affect katanin function in C. elegans. Striatin-interacting kinase phosphatase core components (FARL-11, CASH-1, LET-92, and GCK-1) were katanin inhibitors in mitosis and activators in meiosis, much like HECD-1. By contrast, variable components (SLMP-1, OTUB-2) functioned as activators of katanin activity in mitosis, indicating they may function to alter striatin-interacting kinase phosphatase core function. The core component CCM-3 acted as an inhibitor at both divisions, while other components (MOB-4, C49H3.6) showed weak interactions with katanin mutants. Additional experiments indicate that katanin may be involved with the centralspindlin complex and a tubulin chaperone. HECD-1 shows ubiquitous expression in the cytoplasm throughout meiosis and early development. The differing functions of the different subunits could contribute to the diverse functions of the striatin-interacting kinase phosphatase complex in C. elegans and other organisms.
Collapse
Affiliation(s)
- Tammy Lu
- Department of Biochemistry and Molecular Biology, Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, AL T2N 4N1, Canada
| | - Ryan B Smit
- Department of Biochemistry and Molecular Biology, Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, AL T2N 4N1, Canada
| | - Hanifa Soueid
- Department of Biochemistry and Molecular Biology, Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, AL T2N 4N1, Canada
| | - Paul E Mains
- Department of Biochemistry and Molecular Biology, Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, AL T2N 4N1, Canada
| |
Collapse
|
10
|
Bel Borja L, Soubigou F, Taylor SJP, Fraguas Bringas C, Budrewicz J, Lara-Gonzalez P, Sorensen Turpin CG, Bembenek JN, Cheerambathur DK, Pelisch F. BUB-1 targets PP2A:B56 to regulate chromosome congression during meiosis I in C. elegans oocytes. eLife 2020; 9:65307. [PMID: 33355089 PMCID: PMC7787666 DOI: 10.7554/elife.65307] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 12/17/2020] [Indexed: 12/17/2022] Open
Abstract
Protein Phosphatase 2A (PP2A) is a heterotrimer composed of scaffolding (A), catalytic (C), and regulatory (B) subunits. PP2A complexes with B56 subunits are targeted by Shugoshin and BUBR1 to protect centromeric cohesion and stabilise kinetochore-microtubule attachments in yeast and mouse meiosis. In Caenorhabditis elegans, the closest BUBR1 orthologue lacks the B56-interaction domain and Shugoshin is not required for meiotic segregation. Therefore, the role of PP2A in C. elegans female meiosis is unknown. We report that PP2A is essential for meiotic spindle assembly and chromosome dynamics during C. elegans female meiosis. BUB-1 is the main chromosome-targeting factor for B56 subunits during prometaphase I. BUB-1 recruits PP2A:B56 to the chromosomes via a newly identified LxxIxE motif in a phosphorylation-dependent manner, and this recruitment is important for proper chromosome congression. Our results highlight a novel mechanism for B56 recruitment, essential for recruiting a pool of PP2A involved in chromosome congression during meiosis I.
Collapse
Affiliation(s)
- Laura Bel Borja
- Centre for Gene Regulation and Expression, Sir James Black Centre, School of Life Sciences, University of DundeeDundeeUnited Kingdom
| | - Flavie Soubigou
- Centre for Gene Regulation and Expression, Sir James Black Centre, School of Life Sciences, University of DundeeDundeeUnited Kingdom
| | - Samuel J P Taylor
- Centre for Gene Regulation and Expression, Sir James Black Centre, School of Life Sciences, University of DundeeDundeeUnited Kingdom
| | - Conchita Fraguas Bringas
- Centre for Gene Regulation and Expression, Sir James Black Centre, School of Life Sciences, University of DundeeDundeeUnited Kingdom
| | - Jacqueline Budrewicz
- Ludwig Institute for Cancer ResearchSan DiegoUnited States,Department of Cellular and Molecular Medicine, University of California, San DiegoSan DiegoUnited States
| | - Pablo Lara-Gonzalez
- Ludwig Institute for Cancer ResearchSan DiegoUnited States,Department of Cellular and Molecular Medicine, University of California, San DiegoSan DiegoUnited States
| | | | - Joshua N Bembenek
- Department of Molecular, Cellular, and Developmental Biology, University of MichiganAnn ArborUnited States
| | - Dhanya K Cheerambathur
- Wellcome Centre for Cell Biology & Institute of Cell Biology, School of Biological Sciences, The University of EdinburghEdinburghUnited Kingdom
| | - Federico Pelisch
- Centre for Gene Regulation and Expression, Sir James Black Centre, School of Life Sciences, University of DundeeDundeeUnited Kingdom
| |
Collapse
|