PRKCE and viral infectious disease: Using antibodies that specifically recognize PKD1 and PKD2 phosphorylated in their activation loop at S744/748 (indicative of the activation of the kinase by upstream effectors such as PKCε) and the autophosphorylation of PKD1 at S916 and of PKD2 at S876, it was clear that viral infection induced the phosphorylation of PKD1 and -2 at both sites in a highly reproducible manner in HeLa cells.