Current view of mechanism of cAMP activation . No hormone bound to receptor. GDP bound to a -subunit of G protein. Adenylate cyclase is inactive. Consequences of hormone binding to receptor.
Conformational change occurs in receptor.
Activated receptor binds to G protein. Alfred Gilman and Martin Rodbell received Nobel Prize in 1994 for their discoveries related to G-proteins. Others regulate ion channels. Cyclic AMP cascade . Cyclic AMP activates a protein kinase .