Transcription of beta-casein (CSN2) Authored: Orlic-Milacic, M, 2011-11-04 ERBB4s80:STAT5A complex binds to and stimulates transcription from the beta-casein (CSN2) promoter, and it probably regulates transcription of other lactation-related genes in mammary cells. By over-expressing either human ERBB4cyt1s80 or ERBB4cyt2s80 in mouse mammary cell line HC11 or transgenic mice, Muraoka-Cook et al. showed differential effects of CYT1 and CYT2 isoforms on mammary epithelium. CYT1s80 over-expression decreases cell proliferation, promotes STAT5A-mediated transcription of beta-casein (CSN2) and lactogenic differentiation. In contrast, CYT2s80 over-expression causes epithelial hyperplasia, increased levels of Wnt and beta-catenin, as well as elevated expression of c-myc and cyclin D1 (Muraoka-Cook et al. 2009). Edited: Matthews, L, 2011-11-07 Pubmed15534001 Pubmed18653779 Pubmed19596786 Reactome Database ID Release 431254290 Reactome, http://www.reactome.org ReactomeREACT_116088 Reviewed: Earp HS, 3rd, 2012-02-20 Reviewed: Harris, RC, 2011-11-11 Reviewed: Misior, AM, 2012-02-20 Reviewed: Zeng, F, 2011-11-11