Protein kinase C delta type (PKCδ) (PKCδ)

Protein kinase C delta type (PKCδ) is a calcium-independent, diacylglycerol-dependent serine/threonine kinase encoded by the PRKCD gene, belonging to the novel PKC family and playing contrasting roles in cell survival and death. It functions as a pro-apoptotic protein during DNA damage by activating pathways like BCLAF1-mediated p53 transcription, MAPK signaling, and BAX/BAK mitochondrial pathways, while acting anti-apoptotically in cytokine-induced death or certain cancers via AKT and NF-kappa-B activation. PKCδ regulates cell cycle progression at G1/S and G2/M phases, influences immune responses including B-cell tolerance and NADPH oxidase activity in neutrophils, and modulates platelet function and antifungal immunity. In disease, defects cause autoimmune lymphoproliferative syndrome, and it promotes tumor growth in breast, lung, and colorectal cancers by driving immunosuppressive mononuclear phagocytes, though it can suppress tumors in other contexts. Therapeutically, PKCδ inhibition reprograms tumor-associated myeloid cells to enhance anti-PD-1 immunotherapy and induces senescence in p53 wild-type colorectal cancer, but requires isoform-specific approaches to mitigate off-target risks.

Other names

Protein kinase C deltaPKCdeltanPKC-delta

Inhibition of protein kinase C isotypes, leading to reprogramming of mononuclear phagocytes and enhanced immunotherapy efficacy; induction of cellular senescence in colorectal cancer