NCBI Summary:
This gene encodes a member of a family of proteins with two K homology (KH) RNA-binding domains and a C-terminal RING-finger domain. The protein interacts with mRNA via the KH domains, and the protein shuttles between the nucleus and cytoplasm. Polymorphisms in this gene may contribute to hypertension. [provided by RefSeq, Oct 2009]
General function
RNA processing, RNA binding
Comment
Cellular localization
Cytoplasmic, Nuclear
Comment
Ovarian function
Comment
Expression regulated by
Comment
Ovarian localization
Oocyte
Comment
Oocyte-Specific Expression of Mouse MEX3C652AA in the Ovary and Its Potential Role in Regulating Maternal Fos mRNA. Li X et al. (2016) Currently the humanMEX3Cgene is known to encode an RNA-binding protein of 659 amino acid residues. Here we show that theMEX3Cgene has alternative splicing forms giving rise to multiple MEX3C variants, and some cells expressMEX3Ctranscripts coding for short MEX3C isoforms but not transcripts for MEX3C(659AA) MEX3C(659AA)functions as an adaptor protein for Exportin 1 (XPO1)-mediated nuclear export, since it increases the cytoplasmic distribution of poly(A)(+)RNA, and since addition of the nuclear export signal (NES) sequence to a short MEX3C isoform MEX3C(464AA)confers similar cytoplasmic poly(A)(+)RNA accumulation activity as MEX3C(464AA)-NES.FOSmRNA is a potential MEX3C target mRNA. One mechanism by which MEX3C(659AA)could regulateFOSmRNA is by promoting its nuclear export. Overexpressing MEX3C(659AA)significantly increasedFOSmRNA expression, whereas mutating the NES of MEX3C(659AA)and treating cells with leptomycin B to inhibit XPO1-mediated nuclear export attenuatedFOSupregulation.FOSmRNA is unstable in somatic cells but less so in oocytes; how it is stabilized in the oocytes is unknown. Transcripts for the mouse counterpart of human MEX3C(659AA)(MEX3C(652AA)) are specifically expressed in developing oocytes in the ovary, although totalMex3ctranscripts are expressed in both granulosa cells and oocytes. The specific expression of this long MEX3C isoform in oocytes, its ability to enhanceFOSmRNA nuclear export, and its stability all suggest that MEX3C(464AA)-NES is an RNA-binding protein that preserves maternalFOSmRNA in oocytes.//////////////////