Control of 5‐FOA and 5‐FU resistance by Saccharomyces cerevisiae YJL055W

Abstract In a URA3 /5‐FOA‐based dosage‐suppressor screen, we isolated a plasmid containing the little‐characterized ORF YJL055W . Further analysis showed that this gene did not suppress the mutation of interest. Instead, overexpression of Yjl055Wp directly suppressed the non‐viability of URA3 + cells in the presence of 5‐FOA. Overexpression of Yjl055Wp also suppressed the lethality induced by 5‐FU, but deletion of YJL055W had no detectable effect on resistance to either 5‐FOA or 5‐FU. Based on these observations and a previous report that a yjl055wΔ mutant has increased sensitivity to purine‐analogue mutagens, we suggest that Yjl055Wp may function in one of several pathways for the detoxification of base analogues. However, its precise mechanism of action remains unknown. Copyright © 2008 John Wiley & Sons, Ltd.