The human skeletal muscle glycogenin gene: cDNA, tissue expression and chromosomal localization.

Glycogen synthesis is impaired in first degree relatives of subjects with non-insulin-dependent diabetes mellitus and genes relevant to this metabolic pathway are considered reasonable candidates in the pathogenesis of the disease. In skeletal muscle the de novo synthesis of glycogen in primed by an enzyme named glycogenin. We have cloned the glycogenin cDNA from human skeletal muscle mRNA: human glucogenin is a 333 amino acid protein exhibiting 93% identity with rabbit glycogenin. A single transcript of about 2.4 kb, prominent in skeletal muscle, was detected by Northern blot analysis. In situ hybridization unequivocally located the human glycogenin gene to chromosome 3q25.1. Furthermore, we mapped two intronless glycogenin-related sequences to human chromosomes 12 and 13.