Module 2: Figure protein kinase A (PKA)
The functional organization of protein kinase A (PKA).
There are two types of PKA, type I PKA (PKA I) and type II PKA (PKA II), which differ primarily in the type of R subunits that associate with the C subunits. There are four R subunit isoforms (RIα, RIβ, RIIα and RIIβ), which have somewhat different properties with regard to their affinity for cyclic AMP and their ability to associate with the A-kinase-anchoring proteins (AKAPs). It is these different R subunits that define the properties of the two types of PKA.