Endocrine Abstracts

Nuclear Receptors control many developmental and physiological processes by regulating the expression of networks of genes. Their ability to activate or repress gene transcription depends on the recruitment of coactivators and corepressors that function as scaffolds for the binding of chromatin remodelling enzymes. RIP140 is a ligand dependant corepressor for most, if not all, nuclear receptors with key roles in energy homeostasis and reproduction.RIP140...

The Estrogen Receptor (ER) is a well-studied, ligand dependent transcription factor. We have analysed, by kinetic chromatin immunoprecipitation (ChIP) assays, the mechanisms by which the ER modulates the permissiveness and transcriptional activity of the PS2 gene. Sequential ChIP assays were used to define the cyclical association of approximately 50 different proteins to the pS2 promoter. Key results from these studies are (i) that unliganded and liganded ER direct cycling on...

Rapid activation of diverse signal transduction pathways is thought to play an integral role in the cellular responses to many steroid hormones, including progesterone. This sex steroid is essential for normal reproduction in nearly all species. The recent cloning of a G-protein coupled receptor with the properties of a membrane progestin receptor (mPR) in fish and the subsequent identification of three mammalian homologues (mPR-alpha, -beta, and -gamma) raised the possibility...

Covalent modifications offer an efficient and fast means to modulate protein function. They play a key role in the regulation of steroid receptor-dependent transcription by remodeling the chromatin structural proteins. Steroid receptor coregulator proteins, coactivators and corepressors, which function as signaling intermediates between receptors and chromatin or transcription machinery, often possess or recruit activities that catalyze covalent lysine modifications, such as a...