Section on Hormonal Regulation

Head: Kevin J. Catt

This section investigates the molecular mechanisms of activation, signaling, and function of G protein-coupled receptors, particularly those for angiotensin II (AT1R and AT2R) and gonadotropin-releasing hormone (GnRHR), and their interactions with the EGFR. Studies in hepatic C9 cells identified specific and shared signaling pathways and interactions between the AT1R and the EGFR, and their dependence on caveolin. Also, the invariant chain (Ii/CD74) was identified as a novel interacting protein of the AT1R and is a negative regulator of its expression. In cultured GnRH neurons, pulsatile neurosecretion was dependent on their endogenous GIRK channels, activation of which prevents the firing of action potentials and inhibits episodic GnRH release. BRET analysis performed in GnRH neurons revealed heterodimerization of the GnRHR and GPR54, the receptor that mediates kisspeptin-induced activation of GnRH secretion. The laboratory also investigates the mechanisms by which GnRH activates multiple G proteins in the GnRH neuron. Current studies on GFP-expressing GnRH neurons in rat brain slices are addressing the regulatory roles of endogenous estrogen receptor subtypes in the control of GnRH secretion in the adult animal.

Resources

• Employee Listing
• E-Mail the Lab: catt@helix.nih.gov
• SHR Home Page