Which Is NOT Typically a Step in the CAMP Second-Messenger

Multiple Choice

Which is NOT typically a step in the cAMP second-messenger system?

A) A first messenger binds to a transmembrane receptor.
B) There is dissociation of G-protein subunits.
C) An activated G-protein subunit phosphorylates cAMP-dependent protein kinase.
D) Adenylyl cyclase converts ATP into cAMP.
E) Active cAMP-dependent protein kinase phosphorylates cell proteins.