Diadenosine 5'5"-PI,P4-tetraphosphate (Ap4A), a dinucleoside polyphosphate present in all organisms examined including humans, has several properties expected of a regulatory nucleotide. Ap4A has been proposed to function in cell proliferation and the adaptive response to oxidative stress. The major goal is to determine the function(s) of Ap4A in the yeast, Saccharomyces cerevisiae, during growth, starvation-induced arrest and the cellular response to oxidative stress. The processes that will be examined are growth under different conditions including catabolite repression, arrest of cell growth by deprivation of specific nutrients, and cellular responses to oxidative stress induced by several agents and conditions.
