Function in G protein signaling

Some G proteins stimulate adenylate cyclase that results in elevation of cAMP. cAMP stimulates PKA, which consists of four subunits, two regulatory and two catalytic. Binding of cAMP to the regulatory subunits causes release of the catalytic subunits. These subunits can then enter the nucleus to interact with transcriptional factors, thus affecting gene transcription. The transcription factor CREB, which interacts with a DNA sequence called a cAMP response element (or CRE), is phosphorylated on a serine (Ser 133) in the KID domain. This modification is PKA mediated, and promotes the interaction of the KID domain of CREB with the KIX domain of CBP or p300 and enhances transcription of CREB target genes, including genes that aid gluconeogenesis. This pathway can be initiated by adrenaline activating β-adrenergic receptors on the cell surface.

• Mayr B, Montminy M (Aug 2001). “Transcriptional regulation by the phosphorylation-dependent factor CREB”. Nature Reviews. Molecular Cell Biology. 2 (8): 599–609. doi:10.1038/35085068. PMID 11483993. S2CID 1056720.