Identification of pathways for the uptake of Coenzyme Q in Saccharomyces cerevisiae

Coenzyme Q (ubiquinone or Q) is an essential molecule required for aerobic respiration that helps transfer electrons and protons in the electron transport chain. Many eukaryotic cells, including the yeast Saccharomyces cerevisiae , are capable of de novo synthesis of Q. S. cerevisiae coq mutants lack the ability to synthesize Q, but respiration and growth on a nonfermentable carbon source is rescued when mutant yeast are supplied with exogenous Q containing 6 or 4 isoprenyl side chain groups in the tail (Q 6 or Q 4 ). Deletion of certain endocytosis genes prevents exogenous Q 6 from entering membranous organelles, including mitochondria (Padilla‐López et al. , Genetic evidence for the requirement of the endocytic pathway in the uptake of coenzyme Q 6 in Saccharomyces cerevisiae , 2009 BBA 1788, 1238). However, these same gene deletions do not affect rescue by less hydrophobic Q 4 (James et al. , Complementation of coenzyme Q‐deficient yeast by Q analogues requires the isoprenoid side chain, 2010 FEBS J 277, 2067). Here we examine selected yeast double mutants ( coq2Δ ORFΔ ) for the ability to grow on a nonfermentable carbon source in the presence of exogenously supplied Q 6 or Q 4 . These studies will identify genes and pathways required for trafficking of exogenously supplied Q to the mitochondria, potentially providing insights into mechanisms of Q 10 assimilation in humans. This research was supported by NSF MCB‐1330803.