G1/S Cyclins Interact with Regulatory Subunit of PKA via A-Kinase Anchoring Protein, AKAP95

The mechanisms by which cyclins promote mammalian cell cycle progression havebeen a topic of intense investigation over the last decade. We previously described aninteraction between D-type cyclins and A-kinase anchoring protein, AKAP95. Here, wedemonstrate that AKAP95 can also bind cyclin E1. Association between AKAP95 andcyclins is displaced by CDKs. We show that these G1/S cyclins can interact with RIIsubunit of PKAα through AKAP95. The presence of alternate complexes cyclin-CDKand cyclin D/E-AKAP95-PKA.RIIα suggest different roles of G1/S cyclins and a widerbiological importance of these interactions in cells.