MOLECULAR-CLONING OF A HUMAN POLYPEPTIDE RELATED TO YEAST SDS22, A REGULATOR OF PROTEIN PHOSPHATASE-1

sds22 is a regulatory polypeptide of protein phosphatase-1 that is req uired for the completion of mitosis in both fission and budding yeast, We report here the cDNA cloning of a human polypeptide that is 46% id entical to yeast sds22. The human homolog of sds22 consists of 360 res idues, has a calculated molecular mass of 41.6 kDa and shows a tandem array of 11 leucine-rich repeat structures of 22 residues, Northern an alysis revealed a major transcript of 1.39 kb in all 8 investigated hu man tissues. sds22 was detected by western analysis in both the cytopl asm and the nucleus of rat liver cells as a polypeptide of 44 kDa.