NCBI Summary:
This gene is a member of the Jumonji domain 2 (JMJD2) family and encodes a protein containing a JmjN domain, a JmjC domain, a JD2H domain, two TUDOR domains, and two PHD-type zinc fingers. This nuclear protein functions as a trimethylation-specific demethylase, converting specific trimethylated histone residues to the dimethylated form, and as a transcriptional repressor. [provided by RefSeq, Apr 2009]
General function
Enzyme
Comment
Cellular localization
Cytoplasmic, Nuclear
Comment
Ovarian function
Early embryo development
Comment
KDM4A regulates the maternal-to-zygotic transition by protecting broad H3K4me3 domains from H3K9me3 invasion in oocytes. Sankar A et al. (2020) The importance of germline-inherited post-translational histone modifications on priming early mammalian development is just emerging1-4. Histone H3 lysine 9 (H3K9) trimethylation is associated with heterochromatin and gene repression during cell-fate change5, whereas histone H3 lysine 4 (H3K4) trimethylation marks active gene promoters6. Mature oocytes are transcriptionally quiescent and possess remarkably broad domains of H3K4me3 (bdH3K4me3)1,2. It is unknown which factors contribute to the maintenance of the bdH3K4me3 landscape. Lysine-specific demethylase 4A (KDM4A) demethylates H3K9me3 at promoters marked by H3K4me3 in actively transcribing somatic cells7. Here, we report that KDM4A-mediated H3K9me3 demethylation at bdH3K4me3 in oocytes is crucial for normal pre-implantation development and zygotic genome activation after fertilization. The loss of KDM4A in oocytes causes aberrant H3K9me3 spreading over bdH3K4me3, resulting in insufficient transcriptional activation of genes, endogenous retroviral elements and chimeric transcripts initiated from long terminal repeats during zygotic genome activation. The catalytic activity of KDM4A is essential for normal epigenetic reprogramming and pre-implantation development. Hence, KDM4A plays a crucial role in preserving the maternal epigenome integrity required for proper zygotic genome activation and transfer of developmental control to the embryo.//////////////////
Expression regulated by
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Ovarian localization
Oocyte, Granulosa
Comment
Histone demethylase KDM4A and KDM4B expression in granulosa cells from women undergoing in vitro fertilization. Krieg AJ et al. (2018) To assess expression of the histone demethylases KDM4A and KDM4B in granulosa collected from women undergoing oocyte retrieval and to determine if expression was related to pregnancy outcome. Cumulus and mural granulosa cells were obtained from women undergoing oocyte retrieval. KDM4A and KDM4B mRNA expression was determined by qRT-PCR. KDM4A and KDM4B proteins were immunohistochemically localized in ovarian tissue sections obtained from archival specimens. KDM4A and KDM4B protein was localized to oocytes, granulosa cells, and theca and luteal cells in ovaries from reproductive-aged women. KDM4A and KDM4B mRNA expression was overall higher in cumulus compared to mural granulosa. When comparing granulosa demethylase gene expression, KDM4A and KDM4B mRNA expression was higher in both cumulus and mural granulosa from not pregnant patients compared to patients in the pregnant-live birth group. Histone demethylases KDM4A and KDM4B mRNA are differentially expressed in cumulus and mural granulosa. Expression of both KDM4A and KDM4B mRNA was lower in cumulus granulosa and mural granulosa from pregnant compared to not pregnant patients. These findings suggest that altered expression of histone demethylases may impact epigenetic changes in granulosa cells associated with pregnancy.//////////////////
Follicle stages
Comment
Phenotypes
Mutations
1 mutations
Species: mouse
Mutation name: type: null mutation fertility: infertile - non-ovarian defect Comment: Maternal expression of the JMJD2A/KDM4A histone demethylase is critical for pre-implantation development. Sankar A et al. (2017) Regulation of chromatin composition through post-translational modifications of histones contributes to transcriptional regulation and is essential for many cellular processes, including differentiation and development. JMJD2A/KDM4A is a lysine demethylase with specificity towards di- and tri-methylated lysine 9 and lysine 36 of histone H3 (H3K9me2/me3 and H3K36me2/me3). Here, we report that Kdm4a as a maternal factor plays a key role in embryo survival and is vital for female fertility. Kdm4a(-/-) female mice ovulate normally with comparable fertilization but poor implantation rates, and cannot support healthy transplanted embryos to term. This is due to a role for Kdm4a in uterine function, where its loss causes reduced expression of key genes involved in ion transport, nutrient supply and cytokine signalling, that impact embryo survival. In addition, a significant proportion of Kdm4a deficient oocytes displays a poor intrinsic ability to develop into blastocysts. These embryos cannot compete with healthy embryos for implantation in vivo, highlighting Kdm4a as a maternal effect gene. Thus, our study dissects an important dual role for maternal Kdm4a in determining faithful early embryonic development and the implantation process.//////////////////