Human COQ10A and COQ10B are distinct putative StART domain proteins that restore Q biosynthesis and function in yeast

Abstract

Coenzyme Q (ubiquinone or Q) functions as an essential redox‐active lipid in respiratory electron and proton transport in cellular energy metabolism, and it is an important lipid‐soluble antioxidant in cellular membranes. In Saccharomyces cerevisiae, proteins Coq3‐Coq9, as well as Coq11, assemble into a multi‐subunit protein complex called the CoQ‐synthome, which is required for Q biosynthesis. Coq10, a putative steroidogenic acute regulatory (StAR)‐related lipid transfer (StART) domain protein is not a member of the CoQ‐synthome, but is required for the proper assembly of the CoQ‐synthome, efficient de novo Q biosynthesis during early‐log phase, and the function of Q in respiration and as an antioxidant. Humans possess two isoforms, namely COQ10A and COQ10B. Based on the RNA‐seq data from NCBI, COQ10A is predominantly expressed in heart while COQ10B is present in all tissues, suggesting that COQ10B is probably serving a more general role. Previous studies have shown rescue of S. cerevisiae coq10Δ respiration deficient phenotype by expression of human COQ10A. Here we present new evidence showing rescue of S. cerevisiae coq10Δ by expression of either the human COQ10A or COQ10B homolog, as determined by restoration of respiratory growth on non‐fermentable carbon sources, de novo Q biosynthesis, as well as restoration of the CoQ‐synthome.Support or Funding InformationThis research was supported by NSF MCB‐1330803 and Ruth L. Kirschstein National Research Service Award GM007185.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.