NCBI Summary:
The protein encoded by this gene contains a zinc finger and a Kruppel-associated box (KRAB) domain. KRAB domain is known to be involved in the transcriptional repression of a number of zinc finger proteins. [provided by RefSeq]
General function
Nucleic acid binding, DNA binding, Transcription factor
Comment
Cellular localization
Nuclear
Comment
Ovarian function
Comment
Expression regulated by
FSH
Comment
Ovarian localization
Granulosa
Comment
Co-activation of ER{beta} by a gonadotropin-induced cofactor GIOT-4. Kouzu-Fujita M et al. Estrogen exerts its diverse effects through two subtypes of estrogen receptors (ER), ERalpha and ERbeta. Each subtype has its own distinct function and expression pattern in its target tissues. Little, however, is known about the transcriptional regulatory mechanism of ERbeta in the major ERbeta expressing tissues. Using biochemical methods, we identified and described a novel ERbeta co-activator. This protein, designated GIOT-4, was biochemically purified from 293F cells. It co-activated ERbeta in ovarian granulosa cells. GIOT-4 expression was induced by FSH stimulation. GIOT-4 recruited a SWI/SNF-type complex in ligand-independent manner to ERbeta as a ER subtype-specific physical bridging factor, and induced the following histone modifications in the ERbeta target gene promoters in a human ovarian granulosa cell line (KGN). Indeed, two ERbeta specific target genes were up-regulated by FSH at a specific stage of a normal ovulatory cycle in intact mice. These findings imply the presence of a novel regulatory convergence between the gonadotropin signaling cascade and ERbeta-mediated transcription in the ovary.