A tissue-specific transcription factor containing a homeodomain specifies a pituitary phenotype

摘要: Multiple related cis-active elements required for cell-specific activation of the rat prolactin gene appear to bind a pituitary-specific positive transcription factor(s), referred as Pit-1. DNA complementary Pit-1 mRNA, cloned on basis specific binding AT-rich in and growth hormone genes, encodes 33 kd protein with significant similarity at its carboxyl terminus homeodomains encoded by Drosophila developmental genes. mRNA is expressed exclusively anterior pituitary gland both somatotroph lactotroph cell types, which produce prolactin, respectively. expression heterologous cells (HeLa) selectively activates fusion expression, suggesting that sufficient confer characteristic phenotype. The structure recognition suggests metazoan tissue phenotype controlled family factors contain several highly conserved domains.