Decision letter: BUB-1 targets PP2A:B56 to regulate chromosome congression during meiosis I in C. elegans oocytes

ABSTRACTProtein Phosphatase 2A (PP2A) is an heterotrimer composed of scaffolding (A), catalytic (C), and regulatory (B) subunits with various key roles during cell division. While A and C subunits form the core enzyme, the diversity generated by interchangeable B subunits dictates substrate specificity. Within the B subunits, B56-type subunits play important roles during meiosis in yeast and mice by protecting centromeric cohesion and stabilising the kinetochore-microtubule attachments. These functions are achieved through targeting of B56 subunits to centromere and kinetochore by Shugoshin and BUBR1. In the nematode Caenorhabditis elegans (C. elegans) the closest BUBR1 ortholog lacks the B56 interaction domain and the Shugoshin orthologue is not required for normal segregation during oocyte meiosis. Therefore, the role of PP2A in C. elegans female meiosis is not known. Here, we report that PP2A is essential for meiotic spindle assembly and chromosome dynamics during C. elegans female meiosis. Specifically, B56 subunits PPTR-1 and PPTR-2 associate with chromosomes during prometaphase I and regulate chromosome congression. The chromosome localization of B56 subunits does not require shugoshin orthologue SGO-1. Instead we have identified the kinase BUB-1 as the key B56 targeting factor to the chromosomes during meiosis. PP2A BUB-1 recruits PP2A:B56 to the chromosomes via dual mechanism: 1) PPTR-1/2 interacts with the newly identified LxxIxE short linear motif (SLiM) within a disordered region in BUB-1 in a phosphorylation-dependent manner; and 2) PPTR-2 can also be recruited to chromosomes in a BUB-1 kinase domain-dependent manner. Our results highlight a novel, BUB-1-dependent mechanism for B56 recruitment, essential for recruiting a pool of PP2A required for proper chromosome congression during meiosis I.

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Author response: BUB-1 targets PP2A:B56 to regulate chromosome congression during meiosis I in C. elegans oocytes

10.7554/elife.65307.sa2 ◽

2020 ◽

Author(s):

Laura Bel Borja ◽

Flavie Soubigou ◽

Samuel J P Taylor ◽

Conchita Fraguas Bringas ◽

Jacqueline Budrewicz ◽

...

Keyword(s):

Author Response ◽

C Elegans ◽

Chromosome Congression ◽

Meiosis I

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BUB-1 targets PP2A:B56 to regulate chromosome congression during meiosis I in C. elegans oocytes

eLife ◽

10.7554/elife.65307 ◽

2020 ◽

Vol 9 ◽

Author(s):

Laura Bel Borja ◽

Flavie Soubigou ◽

Samuel J P Taylor ◽

Conchita Fraguas Bringas ◽

Jacqueline Budrewicz ◽

...

Keyword(s):

Meiotic Spindle ◽

Dependent Manner ◽

Female Meiosis ◽

Interaction Domain ◽

C Elegans ◽

Chromosome Congression ◽

Phosphatase 2A ◽

Main Chromosome ◽

Meiosis I

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.

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Phosphorylation of the synaptonemal complex protein SYP-1 promotes meiotic chromosome segregation

10.1101/211672 ◽

2017 ◽

Cited By ~ 1

Author(s):

Aya Sato-Carlton ◽

Chihiro Nakamura-Tabuchi ◽

Stephane Kazuki Chartrand ◽

Tomoki Uchino ◽

Peter Mark Carlton

Keyword(s):

Synaptonemal Complex ◽

Meiotic Chromosome ◽

C Elegans ◽

Chromosome Domains ◽

Chromatid Cohesion ◽

Complex Protein ◽

Chromosomal Passenger ◽

Synaptonemal Complex Protein ◽

A Site ◽

Meiosis I

AbstractChromosomes that have undergone crossing-over in meiotic prophase must maintain sister chromatid cohesion somewhere along their length between the first and second meiotic divisions. While many eukaryotes use the centromere as a site to maintain cohesion, the holocentric organism C. elegans instead creates two chromosome domains of unequal length termed the short arm and long arm, which become the first and second site of cohesion loss at meiosis I and II. The mechanisms that confer distinct functions to the short and long arm domains remain poorly understood. Here, we show that phosphorylation of the synaptonemal complex protein SYP-1 is required to create these domains. Once crossovers are made, phosphorylated SYP-1 and PLK-2 become cooperatively confined to short arms and guide phosphorylated histone H3 and the chromosomal passenger complex to the site of meiosis I cohesion loss. Our results show that PLK-2 and phosphorylated SYP-1 ensure creation of the short arm subdomain, promoting disjunction of chromosomes in meiosis I.

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Cortical recruitment of centralspindlin and RhoA effectors during meiosis I of Caenorhabditiselegans primary spermatocytes

Journal of Cell Science ◽

10.1242/jcs.238543 ◽

2021 ◽

Vol 134 (3) ◽

pp. jcs238543 ◽

Cited By ~ 1

Author(s):

Xiangchuan Wang ◽

Dandan Zhang ◽

Cunni Zheng ◽

Shian Wu ◽

Michael Glotzer ◽

...

Keyword(s):

Cell Biology ◽

Time Lapse ◽

Contractile Ring ◽

Cellular Division ◽

C Elegans ◽

Ring Assembly ◽

Male Gametes ◽

Spatiotemporal Regulation ◽

Haploid Male ◽

Meiosis I

ABSTRACTHaploid male gametes are produced through meiosis during gametogenesis. Whereas the cell biology of mitosis and meiosis is well studied in the nematode Caenorhabditis elegans, comparatively little is known regarding the physical division of primary spermatocytes during meiosis I. Here, we investigated this process using high-resolution time-lapse confocal microscopy and examined the spatiotemporal regulation of contractile ring assembly in C. elegans primary spermatocytes. We found that centralspindlin and RhoA effectors were recruited to the equatorial cortex of dividing primary spermatocytes for contractile ring assembly before segregation of homologous chromosomes. We also observed that perturbations shown to promote centralspindlin oligomerization regulated the cortical recruitment of NMY-2 and impacted the order in which primary spermatocytes along the proximal–distal axis of the gonad enter meiosis I. These results expand our understanding of the cellular division of primary spermatocytes into secondary spermatocytes during meiosis I.This article has an associated First Person interview with the first author of the paper.

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A degron-based strategy reveals new insights into Aurora B function in C. elegans

PLoS Genetics ◽

10.1371/journal.pgen.1009567 ◽

2021 ◽

Vol 17 (5) ◽

pp. e1009567

Author(s):

Nikita S. Divekar ◽

Amanda C. Davis-Roca ◽

Liangyu Zhang ◽

Abby F. Dernburg ◽

Sarah M. Wignall

Keyword(s):

Cell Cycle ◽

Kinase Activity ◽

Aurora B ◽

Cell Cycle Regulators ◽

Transgenic Expression ◽

C Elegans ◽

Chromosome Congression ◽

Independent Functions ◽

Ring Complex ◽

Sumo Pathway

The widely conserved kinase Aurora B regulates important events during cell division. Surprisingly, recent work has uncovered a few functions of Aurora-family kinases that do not require kinase activity. Thus, understanding this important class of cell cycle regulators will require strategies to distinguish kinase-dependent from independent functions. Here, we address this need in C. elegans by combining germline-specific, auxin-induced Aurora B (AIR-2) degradation with the transgenic expression of kinase-inactive AIR-2. Through this approach, we find that kinase activity is essential for AIR-2’s major meiotic functions and also for mitotic chromosome segregation. Moreover, our analysis revealed insight into the assembly of the ring complex (RC), a structure that is essential for chromosome congression in C. elegans oocytes. AIR-2 localizes to chromosomes and recruits other components to form the RC. However, we found that while kinase-dead AIR-2 could load onto chromosomes, other components were not recruited. This failure in RC assembly appeared to be due to a loss of RC SUMOylation, suggesting that there is crosstalk between SUMOylation and phosphorylation in building the RC and implicating AIR-2 in regulating the SUMO pathway in oocytes. Similar conditional depletion approaches may reveal new insights into other cell cycle regulators.

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Trans-generational inheritance of centromere identity requires the CENP-A N-terminal tail in the C. elegans maternal germ line

10.1101/2020.10.05.325985 ◽

2020 ◽

Author(s):

Reinier F. Prosée ◽

Joanna M. Wenda ◽

Caroline Gabus ◽

Kamila Delaney ◽

Francoise Schwager ◽

...

Keyword(s):

De Novo ◽

Germ Line ◽

Protein A ◽

Histone H3 ◽

Centromeric Chromatin ◽

C Elegans ◽

Centromere Function ◽

Centromere Protein A ◽

Histone H3 Variant ◽

Meiosis I

AbstractCentromere protein A (CENP-A) is a histone H3 variant that defines centromeric chromatin and is essential for centromere function. In most eukaryotes CENP-A-containing chromatin is epigenetically maintained, and centromere identity is inherited from one cell cycle to the next. In the germ line of the holocentric nematode Caenorhabditis elegans, this inheritance cycle is disrupted. CENP-A is removed at the mitosis-to-meiosis transition and is established de novo on chromatin during diplotene of meiosis I. Here we show that the N-terminal tail of CENP-A is required for the de novo establishment of centromeres, but dispensable for centromere maintenance during embryogenesis. Worms homozygous for a CENP-A tail deletion maintain a functional centromere during development, but give rise to inviable offspring because they fail to re-establish centromeres in the maternal germ line. We identify the N-terminal tail of CENP-A as a critical domain for the interaction with the conserved kinetochore protein KNL-2, and argue that this interaction plays an important role in setting centromere identity in the germ line. We conclude that centromere establishment and maintenance are functionally distinct in C. elegans.

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Aurora B/C-dependent phosphorylation promotes Rec8 cleavage in mammalian oocytes

10.1101/2021.10.22.465153 ◽

2021 ◽

Author(s):

Elvira Nikalayevich ◽

Safia El Jailani ◽

Damien Cladiere ◽

Yulia Gryaznova ◽

Celia Fosse ◽

...

Keyword(s):

Chromosome Segregation ◽

Kinase Activity ◽

Model Systems ◽

Aurora B ◽

Dependent Manner ◽

Centromere Region ◽

C Elegans ◽

Sister Chromatids ◽

Turn Over ◽

Meiosis I

To generate haploid gametes, cohesin is removed in a stepwise manner from chromosome arms in meiosis I and the centromere region in meiosis II, to segregate chromosomes and sister chromatids, respectively. Meiotic cohesin removal requires cleavage of the meiosis-specific kleisin subunit Rec8 by the protease Separase[1, 2]. In yeast, Rec8 is kept in a non-phosphorylated state by the action of PP2A-B56, which is localised to the centromere region, thereby preventing cohesin removal from this region in meiosis I[3-5]. However, it is unknown whether Rec8 has to be equally phosphorylated for cleavage, and whether centromeric cohesin protection is indeed brought about by dephosphorylation of Rec8 preventing cleavage, in mammalian meiosis. The identity of one or several potential Rec8-specific kinase(s) is also unknown. This is due to technical challenges, as Rec8 is poorly conserved preventing a direct translation of the knowledge gained from model systems such as yeast and C. elegans to mammals, and additionally, there is no turn-over of Rec8 after cohesion establishment, preventing phospho mutant analysis of functional Rec8. To address how Rec8 cleavage is brought about in mammals, we adapted a biosensor for Separase to study Rec8 cleavage in single mouse oocytes by live imaging, and identified phosphorylation sites promoting cleavage. We found that Rec8 cleavage by Separase depends on Aurora B/C kinase activity, and identified a residue promoting cleavage and being phosphorylated in an Aurora B/C kinase-dependent manner. Accordingly, inhibition of Aurora B/C kinase during meiotic maturation impairs endogenous Rec8 phosphorylation and chromosome segregation.

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Spatial and temporal control of targeting Polo-like kinase during meiotic prophase

The Journal of Cell Biology ◽

10.1083/jcb.202006094 ◽

2020 ◽

Vol 219 (11) ◽

Author(s):

James N. Brandt ◽

Katarzyna A. Hussey ◽

Yumi Kim

Keyword(s):

Chromosome Segregation ◽

Meiotic Prophase ◽

Meiotic Chromosome ◽

Holocentric Chromosomes ◽

Cyclin Dependent Kinase ◽

Chromosome Dynamics ◽

C Elegans ◽

Meiotic Progression ◽

Crossover Site ◽

Meiosis I

Polo-like kinases (PLKs) play widely conserved roles in orchestrating meiotic chromosome dynamics. However, how PLKs are targeted to distinct subcellular localizations during meiotic progression remains poorly understood. Here, we demonstrate that the cyclin-dependent kinase CDK-1 primes the recruitment of PLK-2 to the synaptonemal complex (SC) through phosphorylation of SYP-1 in C. elegans. SYP-1 phosphorylation by CDK-1 occurs just before meiotic onset. However, PLK-2 docking to the SC is prevented by the nucleoplasmic HAL-2/3 complex until crossover designation, which constrains PLK-2 to special chromosomal regions known as pairing centers to ensure proper homologue pairing and synapsis. PLK-2 is targeted to crossover sites primed by CDK-1 and spreads along the SC by reinforcing SYP-1 phosphorylation on one side of each crossover only when threshold levels of crossovers are generated. Thus, the integration of chromosome-autonomous signaling and a nucleus-wide crossover-counting mechanism partitions holocentric chromosomes relative to the crossover site, which ultimately defines the pattern of chromosome segregation during meiosis I.

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NIMA-related kinase 1 (NEK1) regulates the localization and phosphorylation of α-Adducin (ADD1) and Myosin X (MYO10) during meiosis

10.1101/110098 ◽

2017 ◽

Cited By ~ 1

Author(s):

Miguel A. Brieño-Enríquez ◽

Stefannie L. Moak ◽

J. Kim Holloway ◽

Paula E. Cohen

Keyword(s):

Meiotic Spindle ◽

Mitotic Spindles ◽

Spindle Formation ◽

Protein Levels ◽

Chromosome Congression ◽

Multipolar Spindles ◽

Summary Statement ◽

Myosin X ◽

And Function ◽

Meiosis I

Summary statement:NEK1 kinase regulates the assembly and function of the meiosis I spindle by phosphorylating α-adducin (ADD1) and thereby facilitating its interaction with Myosin X (MYO10)Abstract:NIMA-related kinase 1 (NEK1) is a serine/threonine and tyrosine kinase that is highly expressed in mammalian germ cells. Mutations in Nek1 induce anemia, polycystic kidney and infertility. In this study we evaluated the role of NEK1 in meiotic spindle formation in both male and female gametes. Our results show that the lack of NEK1 provokes an abnormal organization of the meiosis I spindle characterized by elongated and/or multipolar spindles, and abnormal chromosome congression. The aberrant spindle structure is concomitant with the disruption in localization and protein levels of myosin X (MYO10) and α-adducin (ADD1), both of which are implicated in the regulation of spindle formation during mitosis. Interaction of ADD1 with MYO10 is dependent on phosphorylation, whereby phosphorylation of ADD1 enables its binding to MYO10 on mitotic spindles. Reduction in ADD1 protein in NEK1 mutant mice is associated with hyperphosphorylation of ADD1, thereby preventing the interaction with MYO10 during meiotic spindle formation. Our results reveal a novel regulatory role for NEK1 in the regulation of spindle architecture and function during meiosis.

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