THE HUMAN SKELETAL-MUSCLE GLYCOGENIN GENE - CDNA, TISSUE EXPRESSION, AND CHROMOSOMAL LOCALIZATION

Glycogen synthesis is impaired in first degree relatives of subjects w ith non-insulin-dependent diabetes mellitus and genes relevant to this metabolic pathway are considered reasonable candidates in the pathoge nesis of the disease. In skeletal muscle the de novo synthesis of glyc ogen is primed by an enzyme named glycogenin. We have cloned the glyco genin cDNA from human skeletal muscle mRNA: human glycogenin is a 333 amino acid protein exhibiting 93% identity with rabbit glycogenin. A s ingle transcript of about 2.4 kb, prominent in skeletal muscle, was de tected by Northern blot analysis. Iii situ hybridization unequivocally located the human glycogenin gene to chromosome 3q25.1. Furthermore, we mapped two intronless glycogenin-related sequences to human chromos omes 12 and 13. (C) 1996 Academic Press, Inc.