Detection of suppressed maturation of the human COQ5 protein in the mitochondria following mitochondrial uncoupling by an antibody recognizing both precursor and mature forms of COQ5.
Yeast Coq5p is required for the biosynthesis of coenzyme Q6 (CoQ6), but its human homolog has not been studied. We purified soluble recombinant human COQ5 protein under native conditions and generated an antibody recognizing both precursor and mature forms of COQ5. Mitochondrial localization of the mature form in 143B cells was demonstrated with this antibody. Moreover, a chemical uncoupler in a dose that suppressed CoQ10 levels downregulated the mature form but augmented the precursor form of COQ5. The results that knockdown of the COQ5 gene reduced CoQ10 levels further indicated the critical role of COQ5 in the biosynthesis of CoQ10.
Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan.
Shih-Wei
SW
Chen
Chia-Chi
CC
Liu
Hsiu-Chuan
HC
Yen
D002460:Cell Line; D006801:Humans; D008780:Methyltransferases / Q000032:analysis* / Q000378:metabolism; D008928:Mitochondria / Q000737:chemistry* / Q000201:enzymology; D024101:Mitochondrial Proteins / Q000032:analysis* / Q000378:metabolism; D014451:Ubiquinone / Q000031:analogs & derivatives* / Q000096:biosynthesis
D024101:Mitochondrial Proteins; D014451:Ubiquinone; D008780:Methyltransferases; C583058:COQ5 protein, human; C024989:coenzyme Q10