Activation by ligands of G-protein coupled receptors that interact with the trimeric G-protein alpha-12/beta/gamma causes the exchange of GDP for GTP bound to G protein alpha subunits followed by dissociation of the beta/gamma heterodimers. Free alpha and beta/gamma subunits are active and ...

Protein kinase cAMP-dependent (PKA) is an enzyme playing key role in a number of cellular processes. In its inactivated state, PKA exists as a tetrameric complex of two catalytic subunits (PKA-cat alpha and PKA-cat beta) and two regulatory subunits (PKA-reg) (alpha ...