A Ca(2+)-independent protein kinase C from fission yeast

A protein kinase C homologue of Schizosaccharomyces pombe, pkc1+, was isolated from a genomic library by screening with the Saccharomyces cerevisiae PKC1 probe. From its primary sequence and biochemical properties, we conclude that S. pombe pkc1+ encodes a phospholipid-activated Ca(2+)-independent protein kinase, homologous to the delta/epsilon classes of mammalian protein kinase C. Gene disruption experiments show that pkc1+ is not essential for cell viability; however, overexpression of the protein leads to an abnormal cell morphology and a block in cell separation following mitosis suggestive of a role in cell division. In vitro phosphorylation experiments reveal several potential pkc1+ substrates.