aPKC
aPKC (atypical protein kinase C) refers to a subgroup of the protein kinase C (PKC) family that lacks the calcium‑ and diacylglycerol‑binding domains characteristic of conventional and novel PKCs. The atypical isoforms, primarily PKCζ (encoded by PRKCZ) and PKCι/λ (encoded by PRKCI), are activated primarily through protein–protein interactions and phosphoinositide binding rather than by second‑messenger lipids. Both isoforms possess an N‑terminal regulatory region containing a pseudosubstrate motif and a C‑terminal catalytic domain with conserved serine/threonine kinase activity.
Cell‑biological functions of aPKC are centered on the establishment and maintenance of cell polarity. In epithelial
Regulation of aPKC activity involves phosphorylation of the activation loop (Thr410 in PKCζ, Thr403 in PKCι)
Dysregulation of aPKC has been implicated in cancer, where overexpression or constitutive activation promotes oncogenic signaling,
Because of its central role in polarity and signaling, aPKC remains a focus of pharmacological research, with