Separase cleaves the kinetochore protein Meikin at the meiosis I/II transition

Maier, Nolan K.; Ma, Jun; Lampson, Michael A.; Cheeseman, Iain M.

doi:10.1016/j.devcel.2021.06.019

Cited by 23 publications

(18 citation statements)

References 72 publications

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“…For this, a sensor construct containing full length Rec8 was cloned and in vivo cleavage by Separase was analysed by quantifying loss of co-localization of the two fluorophores in oocytes. A recent 5 study had shown that a Rec8 sensor spanning 297-506aa is not cleaved in vivo, with the caveat that cleavage assays were performed in mitotic cells 29 . In our hands, full-length Rec8 sensor was cleaved in vivo in meiosis I oocytes (Figure 3A).…”

Section: Resultsmentioning

confidence: 99%

“…Accordingly, cleavage was Separase dependent, because it did not take place in conditional Separase knock-out oocytes 31 (Figure 3C, Figure S2C). Therefore, a biosensor containing a Rec8 fragment can be used to dissect the requirements for Separase cleavage in oocytes, unlike expression of a truncated sensor in mitotic cells, which needed to be fused with the protein Meikin to be cleaved in a recent study 29 .…”

Section: Resultsmentioning

confidence: 99%

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

et al. 2022

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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

et al. 2022

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“…Here, we report on the establishment of a system enabling controllable expression of a meiosisspecific complex in mitosis. Similar approaches have been used previously to investigate different aspects of meiosis, such as HR repair and chromosome segregation [8][9][10][11][12] . We express components of the trimeric, meiosis-specific Red1, Hop1 and Mek1 complex (i.e., the RHM complex), and show that this complex can self-assemble even when expressed outside of its natural, physiological environment, i.e., in mitotically-dividing cells.…”

Section: Discussionmentioning

confidence: 99%

“…Meiosis can thus be seen as an adaptation of the mitotic cell cycle. One approach to understand meiosis-specific mechanisms is via reconstitution in non-physiological environments, for example via in vitro biochemical reconstitutions (e.g., [2][3][4][5][6][7] ), or by expressing meiosis-specific factors in non-meiotic cells (e.g., [8][9][10][11][12] ).…”

Section: Introductionmentioning

confidence: 99%

Studying meiosis in mitosis: Activating the meiosis-specific Red1-Hop1-Mek1 complex in mitotic budding yeast cells

Nivsarkar

Chen

Funk

et al. 2022

Preprint

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In mitosis, sequences on sister chromatids are preferred as DNA repair templates, whereas in meiosis interhomolog-based repair is promoted. The switch of template preference during homologous recombinational (HR) repair of DNA breaks is a defining event in sexual reproduction. This preference is needed to establish linkages between homologous chromosomes that support meiotic chromosome segregation. In budding yeast, a central activity that enforces meiotic interhomolog bias is encoded in a meiosis-specific protein kinase complex, consisting of Red1, Hop1 and Mek1 (i.e., the RHM complex). Activation of Mek1 kinase in meiosis - dictated by complex formation and upstream DNA break-dependent signaling - leads to modification of HR factors and the establishment of interhomolog HR repair bias. How meiotic repair bias is established is a central question with implications for sexual reproduction, genetic diversity and genome stability. Studying the role of the RHM complex in DNA repair is complicated by the fact that Red1 and Hop1 are required for efficient meiotic DNA break formation. Here, we conditionally express RHM components in mitotically-dividing cells to show that these factors can autonomously establish the RHM complex outside of its physiological environment. In vivo analysis is complemented with in vitro biochemical reconstitution to analyze the composition of a Red1-Hop1 subcomplex. The RHM complex can be activated under DNA damaging conditions in mitotically-dividing cells, and activation depends on upstream Mec1 kinase function. We use this system to perform a structure-function analysis of RHM complex formation and Mek1 activation. Finally, we demonstrate that expressing active Mek1 in mitosis leads to rad51Δ-like DNA break sensitivity, suggesting that activation of the RHM complex is sufficient to reconstitute (parts of) its physiological function in mediating HR-based repair. This system should enable querying downstream effects of RHM complex action on DNA repair dynamics and template bias. Human homologs of Red1 and Hop1 are often aberrantly re-expressed in cancer cells. Our system has the potential to inform on (dys)functional effects of these genes on genome stability during human tumorigenesis.

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“…Besides the crucial role of separase in mitosis, this enzyme in somatic cells has other functions-for example, in the separation of centrioles [91,92]. Separase also has a specific role in oocytes besides cohesion cleavage, which is to cleave the kinetochore protein Meikin involved in Rec8 protection during meiosis I [93]. To our knowledge, there is no information about the regulation of separase mRNA or the protein levels during the somatic cell cycle, though more so in embryos; however, recent data from yeasts suggest that the translation of separase is not very efficient [94].…”

Section: The Control Of Chromosome Separation In Oocytes and Early Embryosmentioning

confidence: 99%

Impact of Global Transcriptional Silencing on Cell Cycle Regulation and Chromosome Segregation in Early Mammalian Embryos

Anger

Radonova

Horakova

et al. 2021

IJMS

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The onset of an early development is, in mammals, characterized by profound changes of multiple aspects of cellular morphology and behavior. These are including, but not limited to, fertilization and the merging of parental genomes with a subsequent transition from the meiotic into the mitotic cycle, followed by global changes of chromatin epigenetic modifications, a gradual decrease in cell size and the initiation of gene expression from the newly formed embryonic genome. Some of these important, and sometimes also dramatic, changes are executed within the period during which the gene transcription is globally silenced or not progressed, and the regulation of most cellular activities, including those mentioned above, relies on controlled translation. It is known that the blastomeres within an early embryo are prone to chromosome segregation errors, which might, when affecting a significant proportion of a cell within the embryo, compromise its further development. In this review, we discuss how the absence of transcription affects the transition from the oocyte to the embryo and what impact global transcriptional silencing might have on the basic cell cycle and chromosome segregation controlling mechanisms.

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Separase cleaves the kinetochore protein Meikin at the meiosis I/II transition

Cited by 23 publications

References 72 publications

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

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

Studying meiosis in mitosis: Activating the meiosis-specific Red1-Hop1-Mek1 complex in mitotic budding yeast cells

Impact of Global Transcriptional Silencing on Cell Cycle Regulation and Chromosome Segregation in Early Mammalian Embryos

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