Molecular cloning and chromosomal localization of a human skeletal muscle PP-1?1 cDNA

Type-1-protein phosphatase (PP-1) activity is reduced in skeletal muscle from human subjects with insulin resistance (Kida et al. 1990). This 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-1γ1 cDNA was isolated from human skeletal muscle. The nucleotide sequence contains a 957-nucleotide open reading frame encoding an amino acid sequence identical to that encoded by rat liver PP-1γ1 cDNA. Northern blot analysis shows PP-1γ1-specific mRNA is expressed in human heart, brain, placenta, lung, liver, skeletal muscle, kidney, and pancreas. PP-1γ1 was localized to human Chromosome 12.