Protein kinase C phosphorylates tau and induces its functional alterations

Abstract

We found that tau, one of the major microtubule‐associated proteins, is a good substrate for protein kinase C. The phosphorylation occurred mainly on serine residues and the sites phosphorylated by protein kinase C were largely different from those phosphorylated by cAMP‐dependent protein kinase as analyzed by phosphopeptide mapping. The protein kinase C‐mediated phosphorylation of tau reduced its abilities to promote tubulin polymerization and to cross‐link actin filaments. The reduction in its abilities was in proportion to the number of phosphates incorporated into tau.