Intracellular cAMP content and the induction of alternative oxidase in theyeast Yarrowia lipolytica

The effect of cyanide, antimycin A, ethanol, and acetate on the induction o f alternative oxidase in the yeast Yarrowia lipolytica VKM Y-155 was studie d. The aerobic incubation of logarithmic-phase cells, whose respiration is sensitive to cyanide, in the presence of the aforementioned compounds led t o the development of cyanide-resistant respiration, which could be suppress ed by benzohydroxamic acid, an inhibitor of alternative oxidases. The incub ation of cells with cyanide, ethanol, or acetate raised the intracellular p ool of cAMP, which attained maximal values after a 2- to 3-min incubation p eriod, then rapidly decreased to the initial value and bid not change over the next three hours of incubation. The possible role of cAMP in the induct ion of alternative oxidase in yeast cells is discussed.