Saccharomyces cerevisiae (baker’s yeast) serves as an excellent model for studies on coenzyme Q biosynthesis and function because it is a simple model and is highly conserved with respect to human CoQ biosynthesis.
Coenzyme Q (Q or ubiquinone) is a redox-active lipid consisting of a fully substituted benzoquinone ring and a lipophilic polyisoprenoid “tail”, which serves to anchor Q in biological membranes. The reversible redox chemistry of Q allows it to function in mitochondrial electron transport and as a lipid-soluble antioxidant. Saccharomyces cerevisiae (baker’s yeast) serves as an excellent model for studies on CoQ biosynthesis and function because it is a simple model and is highly conserved with respect to human CoQ biosynthesis. “Q-less” yeast mutants harbouring mutations in COQ genes required for Q biosynthesis are respiratory defective and hypersensitive to treatment with polyunsaturated fatty acids. In yeast, several of the Coq polypeptides necessary for the biosynthesis of Q have been shown to be associated in a high molecular mass complex that localizes in the inner mitochondrial membrane, and has been termed the ‘CoQ-synthome’. Genetic, biochemical, and physical experiments have demonstrated the existence of this complex and have given insight to some of the particular protein-protein associations. Additionally, the stability of this complex has been shown to be dependent on Q and Q-intermediates, which are also associated with this complex. Elucidating the roles of the Coq polypeptides will aid our understanding and treatment of multiple diseases caused by Q-deficiencies and will provide insights regarding longevity and issues related to aging in humans.
Speaker: Professor Catherine Clarke received her B.S. and Ph.D. from UCLA. Following her postdoctoral work at Princeton, she returned to UCLA and in 1993 joined the Chemistry and Biochemistry Department. The research in her group elucidates the biosynthetic pathways of coenzyme Q (ubiquinone or Q) biosynthesis and probes the physiological roles of Q.