The 26-amino acid beta-motif of the Pit-1beta transcription factor is a dominant and independent repressor domain.

ABSTRACT: The POU-homeodomain transcription factor Pit-1 governs the pituitary cell-specific expression of Pit-1, GH, prolactin (PRL), and TSHbeta genes. Alternative splicing generates Pit-1beta, which contains a 26-amino acid beta-domain inserted at amino acid 48, in the middle of the Pit-1 transcription activation domain (TAD). Pit-1beta represses GH, PRL, and TSHbeta promoters in a pituitary-specific manner, because Pit-1beta activates these same promoters in HeLa nonpituitary cells. Here we comprehensively analyze the role of beta-domain sequence, position, and context, to elucidate the mechanism of beta-dependent repression. Repositioning the beta-motif to the Pit-1 amino terminus, hinge, linker, and carboxyl terminus did not affect its ability to repress basal rat (r) PRL promoter activity in

SUBMITTER: Jonsen MD 

PROVIDER: S-EPMC2737555 | biostudies-literature | 2009 Sep

REPOSITORIES: biostudies-literature