MOLECULAR-CLONING AND CHROMOSOMAL LOCALIZATION OF A HUMAN SKELETAL-MUSCLE PP-1-GAMMA-1 CDNA

Type-1-protein phosphatase (PP-1) activity is reduced in skeletal musc le from human subjects with insulin resistance (Kida et al. 1990). Thi s reduced phosphatase activity probably leads to the abnormal insulin action for glucose storage observed in insulin-resistant subjects. In the present study, a human homolog of rat liver PP-1 gamma 1 cDNA was isolated from human skeletal muscle. The nucleotide sequence contains a 957-nucleotide open reading frame encoding an amino acid sequence id entical to that encoded by rat liver PP-1 gamma 1 cDNA. Northern blot analysis shows PP-1 gamma 1-specific mRNA is expressed in human heart, brain, placenta, lung, liver, skeletal muscle, kidney, and pancreas. PP-1 gamma 1 was localized to human Chromosome 12.