NCBI Summary:
This gene encodes a protein that belongs to the E2F family of transcription factors. This protein regulates E2F-dependent transcriptional activation and cell proliferation, mainly through the E2F/retinoblastoma protein pathway. It also functions in the regulation of JUN oncogene expression. This protein shows distinctive nuclear-mitotic apparatus distribution, it is involved in spindle organization from prometaphase, and may also play a role as a midzone factor involved in chromosome segregation or cytokinesis. Two alternatively spliced transcript variants encoding the same protein have been noted for this gene. Two pseudogenes have also been identified on chromosome 1. [provided by RefSeq, May 2014]
General function
Transcription factor
Comment
Cellular localization
Nuclear
Comment
Ovarian function
Comment
Expression regulated by
mir424
Comment
PCOS follicular fluid derived exosomal miR-424-5p induces granulosa cells senescence by targeting CDCA4 expression. Yuan D et al. (2021) Polycystic ovary syndrome (PCOS) is a heterogeneous reproductive disease, characterized by increased ovarian androgen biosynthesis, chronic anovulation and polycystic ovaries. The objective of this study was to identify the altered miRNA expression profiles in follicular fluid derived exosomes isolated from PCOS patients and to investigate the molecular functions of exosomal miR-424-5p. Herein, small RNA sequencing showed that twenty-five miRNAs were differentially expressed between control and PCOS group. The alterations in the miRNA profile were related to the endocrine resistance, cell growth and proliferation, cellular senescence and insulin signaling pathway. Among these differentially expressed miRNAs, we found that the expression of miR-424-5p was significantly decreased in PCOS exosomes and primary granulosa cells (GCs). Exosome-enriched miR-424-5p significantly promoted GCs senescence and suppressed cell proliferation. Similar to the results obtained in the cells transfected with miR-424-5p mimic, miR-424-5p mimic significantly decreased cell proliferation ability and induced senescence, but treatment with miR-424-5p inhibitor got the opposite results. In addition, cell division cycle associated 4 (CDCA4) gene displayed an inverse expression pattern to those of miR-424-5p, was identified as the direct target of miR-424-5p. Overexpression of CDCA4 reversed the effects of exosomal miR-424-5p on GCs via activation of Rb/E2F1 signaling pathway. These results demonstrate that exosomal miR-424-5p inhibits GCs proliferation and induces cellular senescence in PCOS through blocking CDCA4-mediated Rb/E2F1 signaling. Our findings provide new information on abnormal follicular development in PCOS.//////////////////