Cloning of mouse Cited4, a member of the CITED family p300/CBP-binding transcriptional coactivators: induced expression in mammary epithelial cells.
Yahata T., Takedatsu H., Dunwoodie SL., Bragança J., Swingler T., Withington SL., Hur J., Coser KR., Isselbacher KJ., Bhattacharya S., Shioda T.
The CITED family proteins bind to CBP/p300 transcriptional integrators through their conserved C-terminal acidic domain and function as coactivators. The 21-kDa mouse Cited4 protein, a novel member of the CITED family, interacted with CBP/p300 as well as isoforms of the TFAP2 transcription factor, coactivating TFAP2-dependent transcription. The cited4 gene consisted of only a single exon located on chromosome 4 at 56.5-56.8 cM flanked by marker genes kcnq4 and scml1. Expression of Cited4 protein was strong and selective in embryonic hematopoietic tissues and endothelial cells. In adult animals, Cited4 showed strong milk cycle-dependent induction in pregnant and lactating mammary epithelial cells. Strong induction of Cited4 expression was also observed in SCp2 mouse mammary epithelial cells during their prolactin-dependent in vitro differentiation. These results implied possible roles for Cited4 in regulation of gene expression during development and differentiation of blood cells, endothelial cells, and mammary epithelial cells.