The isoform of protein kinase C (PKC) has been identified as a central signaling element in the genesis of cardioprotection against ischemia. However, the detailed infrastructure of PKC-dependent signaling on the heart is not known. Our laboratory has designed and implemented a novel proteomic platform for the characterization of PKC signaling complexes in the heart. We found that these complexes are dynamically regulated in the normal heart and in the heart protected against ischemic insult. Furthermore, we have characterized numerous modules within these PKC signaling complexes that accomplish specific subcellular tasks during cardioprotection.

So far, the subproteome defined by these PKC complexes has been characterized by our laboratory to contain at least 93 proteins. The long term goal of the laboratory is to characterize the roles of all proteins within the PKC signaling system in the heart on four fundamental levels: 1) spatial localization; 2) temporal regulation; 3) expression and post-translational modification; and 4) functional importance. This will include the generation of cell culture and live animal models to verify the contribution of individual molecules in the PKC subproteome to the phenotypes of ischemic injury and cardioprotection (see Ping et al. J Clin Invest. 2002). Importantly, we are also in the process of developing non-denaturing methods to examine native protein complexes in the heart. In addition, we are implementing this proteomic platform to map other signaling systems important to cardiac function in health and disease.