NCBI Summary:
This gene encodes a protein that may have acetyltransferase activity and may be required for the establishment of sister chromatid cohesion during the S phase of mitosis. Mutations in this gene have been associated with Roberts syndrome. [provided by RefSeq, Jul 2008]
General function
Chromosome organization, Enzyme
Comment
Cellular localization
Nuclear
Comment
Ovarian function
Germ cell development
Comment
Cohesin acetyltransferase Esco2 regulates SAC and kinetochore functions via maintaining H4K16 acetylation during mouse oocyte meiosis. Lu Y et al. (2017) Sister chromatid cohesion, mediated by cohesin complex and established by the acetyltransferases Esco1 and Esco2, is essential for faithful chromosome segregation. Mutations in Esco2 cause Roberts syndrome, a developmental disease characterized by severe prenatal retardation as well as limb and facial abnormalities. However, its exact roles during oocyte meiosis have not clearly defined. Here, we report that Esco2 localizes to the chromosomes during oocyte meiotic maturation. Depletion of Esco2 by morpholino microinjection leads to the precocious polar body extrusion, the escape of metaphase I arrest induced by nocodazole treatment and the loss of BubR1 from kinetochores, indicative of inactivated SAC. Furthermore, depletion of Esco2 causes a severely impaired spindle assembly and chromosome alignment, accompanied by the remarkably elevated incidence of defective kinetochore-microtubule attachments which consequently lead to the generation of aneuploid eggs. Notably, we find that the involvement of Esco2 in SAC and kinetochore functions is mediated by its binding to histone H4 and acetylation of H4K16 both in vivo and in vitro. Thus, our data assign a novel meiotic function to Esco2 beyond its role in the cohesion establishment during mouse oocyte meiosis.//////////////////
Identification and Expression of Potential Regulators of the Mammalian Mitotic-to-Meiotic Transition. Hogarth CA et al. Meiosis is unique to germ cells and occurs in a sex-specific manner. The genes regulating meiotic initiation in either sex are yet to be fully elucidated. Recent studies have revealed the importance of retinoic acid and one of its target genes, Stra8, in meiotic initiation in both sexes. Microarray analysis of whole murine embryonic ovary and postnatal testis time course data revealed a single peak of Stra8 expression in each organ at the onset of meiosis; at E14.5 in the ovary and 10 dpp in the testis. In order to identify other genes involved in the initiation of meiosis in mammals, murine testis and ovary microarray data were examined more closely for transcripts with expression profiles similar to Stra8. Three such candidates include establishment of cohesion 1 homolog 2 (Esco2), encoding a protein essential for sister chromatid cohesion, SET domain, bifurcated 2 (Setdb2), the mouse ortholog of Eggless which is essential for oogenesis in Drosophila, and ubiquitin activating enzyme 6 (Uba6), a gene with fivefold higher expression in human and mouse testes than any other organ. In situ hybridization and immunohistochemistry or immunofluorescence were performed to localize Esco2, Setbd2 and Uba6 expression in the developing testis. The cellular expression pattern localized all three of these transcripts and their respective proteins to germ cells transitioning from mitosis to meiosis, hence supporting the hypothesis of their involvement in the initiation of meiosis. Future research will be directed at determining a specific role for these three proteins in germ cell differentiation.
Expression regulated by
Comment
Ovarian localization
Primordial Germ Cell
Comment
Localization and Regulation of Murine Esco2 During Male and Female Meiosis. Evans EB et al. Meiosis is essential for generation of healthy gametes in both sexes and involves recombination and segregation of homologous chromosomes to produce haploid gametes. The initiation of meiosis in both sexes relies upon retinoic acid (RA) (Griswold MD, Hogarth CA, Bowles J, Koopman P. Initiating Meiosis: The Case for Retinoic Acid. Biol Reprod 2012; 86:35, 1-7). Previous studies demonstrated that stimulated by retinoic acid gene 8 (Stra8) was required for meiotic progression in both the mouse ovary and postnatal testis. To identify additional candidates that may play a role during meiosis, microarray databases were utilized to generate lists of transcripts with expression profiles similar to Stra8 in the embryonic ovary and postnatal testis. One such gene, establishment of cohesion 1 homolog 2 (S. cerevisiae) (Esco2), has been described as a regulator of sister chromatid cohesion during mitosis. This study describes the first in depth analysis of ESCO2 localization and regulation during meiosis in both males and females. ESCO2 colocalized with gamma H2A histone family, member X (H2AFX) in pachytene spermatocytes indicating that ESCO2 is a component of the XY body. In pachytene cells of the embryonic ovary, ESCO2 colocalized with H2AFX which is consistent with ESCO2 being present in the areas of double-stranded breaks. In addition the expression of Esco2 was found to be regulated by RA in the postnatal testis. These data indicate that ESCO2 may play a vital role in meiosis in both males and females.