NCBI Summary:
Centromeres are the differentiated chromosomal domains that specify the mitotic behavior of chromosomes. This gene encodes a centromere protein which contains a histone H3 related histone fold domain that is required for targeting to the centromere. Centromere protein A is proposed to be a component of a modified nucleosome or nucleosome-like structure in which it replaces 1 or both copies of conventional histone H3 in the (H3-H4)2 tetrameric core of the nucleosome particle. The protein is a replication-independent histone that is a member of the histone H3 family. Alternative splicing results in multiple transcript variants encoding distinct isoforms. [provided by RefSeq, Nov 2015]
General function
Cell organization, Chromosome organization
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Cellular localization
Nuclear, centrosome
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Ovarian function
Oocyte maturation
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Quiescent Cells Actively Replenish CENP-A Nucleosomes to Maintain Centromere Identity and Proliferative Potential. Swartz SZ et al. (2019) Centromeres provide a robust model for epigenetic inheritance as they are specified by sequence-independent mechanisms involving the histone H3-variant centromere protein A (CENP-A). Prevailing models indicate that the high intrinsic stability of CENP-A nucleosomes maintains centromere identity indefinitely. Here, we demonstrate that CENP-A is not stable at centromeres but is instead gradually and continuously incorporated in quiescent cells including G0-arrested tissue culture cells and prophase I-arrested oocytes. Quiescent CENP-A incorporation involves the canonical CENP-A deposition machinery but displays distinct requirements from cell cycle-dependent deposition. We demonstrate that Plk1 is required specifically for G1 CENP-A deposition, whereas transcription promotes CENP-A incorporation in quiescent oocytes. Preventing CENP-A deposition during quiescence results in significantly reduced CENP-A levels and perturbs chromosome segregation following the resumption of cell division. In contrast to quiescent cells, terminally differentiated cells fail to maintain CENP-A levels. Our work reveals that quiescent cells actively maintain centromere identity providing an indicator of proliferative potential.//////////////////
CENP-A regulates chromosome segregation during the first meiosis of mouse oocytes. Li L et al. (2017) Proper chromosome separation in both mitosis and meiosis depends on the correct connection between kinetochores of chromosomes and spindle microtubules. Kinetochore dysfunction can lead to unequal distribution of chromosomes during cell division and result in aneuploidy, thus kinetochores are critical for faithful segregation of chromosomes. Centromere protein A (CENP-A) is an important component of the inner kinetochore plate. Multiple studies in mitosis have found that deficiencies in CENP-A could result in structural and functional changes of kinetochores, leading to abnormal chromosome segregation, aneuploidy and apoptosis in cells. Here we report the expression and function of CENP-A during mouse oocyte meiosis. Our study found that microinjection of CENP-A blocking antibody resulted in errors of homologous chromosome segregation and caused aneuploidy in eggs. Thus, our findings provide evidence that CENP-A is critical for the faithful chromosome segregation during mammalian oocyte meiosis.//////////////////: Ageing Oocyte Chromosomes Rely on Amazing Protein Stability. Toth A et al. (2016) Meiotic chromosome segregation in mouse oocytes seems to rely on highly stable cohesins and CENP-A produced in the fetus and not replenished during postnatal life. Hence, demise of these proteins may underpin declining oocyte quality in ageing mammals and thus marks a major problem of reproductive health in humans.//////////////////
Long-Term Retention of CENP-A Nucleosomes in Mammalian Oocytes Underpins Transgenerational Inheritance of Centromere Identity. Smoak EM et al. (2016) Centromeres control genetic inheritance by directing chromosome segregation but are not genetically encoded themselves. Rather, centromeres are defined by nucleosomes containing CENP-A, a histone H3 variant [1]. In cycling somatic cells, centromere identity is maintained by an established cell-cycle-coupled CENP-A chromatin assembly pathway, but how centromeres are inherited through the mammalian female germline is unclear because of the long (months to decades) prophase I arrest. Here we show that mouse oocytes retain the pool of CENP-A nucleosomes assembled before birth, and that this pool is sufficient for centromere function, fertility, and genome transmission to embryos. Indeed, oocytes lack any measurable CENP-A nucleosome assembly through the entire fertile lifespan of the female (>1 year). Thus, the remarkable stability of CENP-A nucleosomes confers transgenerational centromere identity in mammals.//////////////////
Expression regulated by
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Ovarian localization
Oocyte
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The human cumulus-oocyte complex gene-expression profile. Assou S et al. BACKGROUND: The understanding of the mechanisms regulating human oocyte maturation is still rudimentary. We have identified transcripts differentially expressed between immature and mature oocytes and cumulus cells.
Follicle stages
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Phenotypes
Mutations
1 mutations
Species: human
Mutation name: type: naturally occurring fertility: subfertile Comment: Array-CGH diagnosis in ovarian failure: identification of new molecular actors for ovarian physiology. Jaillard S et al. (2016) Ovarian failure (OF) is considered premature if it occurs before the age of 40. This study investigates the genetic aetiology underlying OF in women under the age of 40 years. We conducted an experimental prospective study performing all genome microarrays in 60 patients younger than 40 years presenting an OF revealed by a decrease of circulating Anti-Müllerian Hormone (AMH) and leading to an oocyte donation program. We identified nine significant copy number variations (CNVs) including candidate genes potentially implicated in reproductive function. These genes are principally involved in cell division and chromosome segregation (SYCE1, CLASP1, CENP-A, CDC16), in ciliary development and/or function (RSPH1, KIF24), are linked with known gonadal genes or expressed in female genital tract (CSMD1, SEMA6D, KIAA1324). Our data strengthen the idea that microarrays should be used in combination with karyotype for aetiological assessment of patients with OF. This analysis may have a therapeutic impact as the identification of new molecular actors for gonadal development or ovarian physiology is useful for the prediction of an ovarian reserve decline and makes possible preventive fertility preservation.//////////////////