Compartmentalized Protein Kinase C Activation in Ovarian Carcinoma Cells

Protein kinase C (PKC), a family of phospholipid-dependent serine/threonine kinases, plays a cardinal role in malignancy (1-5). PKC isozymes can be categorized into three groups: Group A or conventional (c) PKC: α, βI, βII, and γ; Group B or novel (n) PKC: δ, ε, η, θ, and µ, and Group C or atypical (a) PKC: ζ and λ (ι) (1,3,4). Whereas cPKCs require Ca(2+)and diacylglycerol (DAG) phorbol esters for their activities, nPKCs and aPKCs are Ca(2+)-independent. aPKCs are also insensitive to diacylglycerol and phorbol esters (1,3,4).