LAG2, A GENE THAT DETERMINES YEAST LONGEVITY

Saccharomyces cerevisiae has a limited life span, measured by the repr oductive capacity of the individual cell. Several genes that are diffe rentially expressed during the yeast life span have been isolated. One of these genes, LAG2, has been characterized for its role in longevit y. LAG2 is preferentially expressed in young cells. It encodes a predi cted 680 amino acid protein with a putative transmembrane helix. The s equence does not show significant similarity to any other DNA or prote in sequences in the databases. Deletion of LAG2 in a haploid strain di d not affect growth, but it resulted in a 50% decrease in the mean and maximum life span. When LAG2 was overexpressed, the mean and maximum life span of the yeasts was extended by about 36% and 54%, respectivel y. These results indicate that this is a longevity-assurance gene in y east.