Previously, we found evidence for linkage of insulin resistance and type 2 diabetes with a cluster of microsatellite markers at chromosomal 7q. Subsequently, we have mapped to this segment the PPP1R3 gene encoding the glycogen-targeting subunit of type-1 protein phosphatase that regulates glycogen synthesis in skeletal muscle. Furthermore, we found a polymorphism in this gene that seems to contribute to insulin resistance and type 2 diabetes in the Pima Indians by affecting the expression of this subunit (see project #Z01DK 69058). Project now terminated.
