Functional proteomic analysis of protein kinase C epsilon signaling complexes in the normal heart and during cardioprotection.

Using two-dimensional electrophoresis, mass spectrometry, immunoblotting, and affinity pull-down assays, we found that myocardial protein kinase C epsilon (PKCepsilon) is physically associated with at least 36 known proteins that are organized into structural proteins, signaling molecules, and stress-responsive proteins. Furthermore, we found that the cardioprotection induced by activation of PKCepsilon is coupled with dynamic modulation and recruitment of PKCepsilon-associated proteins. The results suggest heretofore-unrecognized functions of PKCepsilon and provide an integrated framework for the understanding of PKCepsilon-dependent signaling architecture and cardioprotection.