Overview:

PKCζ is an atypical isoform of the PKC family. PKCζ is found in both particulate and soluble fractions and cannot be activated by phorbol ester. Overexpression of PKCζ and subsequent phorbol ester treatment abolished phorbol ester-induced reduction in cell proliferation (1). Overexpression of PKCζ also potentiates phorbol ester-induced mitogen-activated protein (MAP) kinase activation in a PKC-dependent manner. PKCζ is an upstream modulator of p70S6K, an important regulator of cell proliferation (2).

References:

1. Kim, SJ. Et al: Phorbol ester effects in atypical protein kinase C zeta overexpressing NIH3T3 cells: possible evidence for crosstalk between protein kinase C isoforms. Biochem Biophys Res Commun. 1997 Aug 18;237(2):336-9.

2. Romanelli, A. et al: p70 S6 kinase is regulated by protein kinase Czeta and participates in a phosphoinositide 3-kinase-regulated signalling complex. Mol Cell Biol. 1999 Apr;19(4):2921-8.