Anaerobic growth of Saccharomyces cerevisiae alleviates the lethal effect of phosphotyrosyl phosphatase activators depletion.

Saccharomyces cerevisiae homologues of phosphotyrosyl phosphatase activator(PTPA) are encoded by RRD1 and RRD2, genes whose combined deletion is synthetic lethal. Previously we have shown that the lethality of rrd1,2Δ can be suppressed by increasing the osmolarity of the medium. Here we show that the lethality of rrd1,2Δ is also suppressed under oxygen-limited conditions. The absence of respiration per se is not responsible for the suppression since elimination of the mitochondrial genome or a block in heme biosynthesis fail to rescue the rrd1,2Δ double mutation.