PRKCA

PRKCA, or protein kinase C alpha, is a gene encoding the enzyme protein kinase C alpha (PKCα), a member of the conventional protein kinase C family. PKCα is a calcium- and diacylglycerol-dependent serine/threonine kinase that participates in diverse signal transduction pathways. In resting cells, PKCα resides mainly in the cytosol; upon activation by elevations in intracellular calcium and DAG, it translocates to cellular membranes where it becomes catalytically active and can phosphorylate substrate proteins.

PKCα phosphorylates numerous substrates that regulate cytoskeletal dynamics, vesicle trafficking, and gene expression. Notable substrates include MARCKS; through these phosphorylation events, PKCα influences cell shape, adhesion, migration, and proliferation. PKCα also modulates signaling cascades such as MAPK and transcription factor activity in a context-dependent manner, contributing to differentiation and survival decisions.

PKCα is one of several conventional PKCs requiring both calcium and DAG for activation, distinguishing it from other PKCs. Its activity is tightly regulated by phosphorylation, membrane localization, and feedback mechanisms; prolonged exposure to activating signals can lead to downregulation via degradation or sequestration.

Altered PRKCA expression or PKCα activity has been observed in various cancers and other diseases, and pharmacological modulation of PKCα has been explored in preclinical and clinical studies. The precise roles of PKCα in disease can be context-dependent, acting as a tumor promoter in some settings and a tumor suppressor in others.