Novel Saccharomyces cerevisiae gene, MRK1, encoding a putative protein kinase with similarity to mammalian glycogen synthase kinase-3 and Drosophila Zeste-White3/Shaggy.

A Saccharomyces cerevisiae gene was identified that would encode a protein similar to the mammalian protein kinase glycogen synthase kinase-3 (GSK-3) and the Drosophila Zeste-White3/Shaggy gene product. The open reading frame predicts a 375 amino acid polypeptide with a putative protein kinase domain that displays 70% and 39% identity, respectively, to two known yeast proteins, Mds1p and Mck1p. The new gene, designated MRK1 (Mds1p Related Kinase), is located on chromosome IV. Disruption of MRK1 was not lethal and did not elicit any alteration in glycogen accumulation. In addition, an mck1 mds1 mrk1 triple disruptant was viable.