Effect of caffeine on recovery from DEB-induced cell inactivation in UV-sensitive mutants of Saccharomyces cerevisiae.

The UV-sensitive yeast mutants rad3 and rad6 are highly sensitive to diepoxybutane (DEB) as compared with the RAD strain. The two mutants show differential response to liquid holding (LH) after exposure to DEB and UV. The survival of rad3 increases markedly after DEB and decreases after UV. Caffeine significantly affects LH recovery of DEB-treated RAD strain, slightly decreases recovery of rad3 and has almost no effect on survival of rad6. When DEB-treated cultures are plated immediately on caffeine-containing medium, survival of rad3 decreases more significantly than that of the RAD strain, whereas survival of rad6 is only slightly decreased as compared with the untreated cultures. Possible mechanisms of recovery from DEB-induced cell damage are discussed.