PKA regulates processes as diverse as growth, sperm motility, memory, and metabolism. In its inactive state, PKA exists as a tetrameric complex of two catalytic (C) subunits and a regulatory (R) subunit dimer. When the intracellular signaling molecule cyclic adenosine monophosphate (cAMP) binds to the R subunit, it facilitates dissociation and activation of the C subunits.
We have identified, cloned and characterized all four human genes encoding the R subunits RIα, RIβ,RIIα and RIIβ and all three human genes encoding the C subunits Cα, Cβ and Cγ.
Furthermore, we have identified several splice variants of the R and C subunits and their potential functions. The splice variants Cα1 and Cβ1 appear to be ubiquitously expressed, whereas the splice variant CαS is only expressed in sperm cells, and the splice variant Cβ2 is highly expressed in lymphoid tissue.