Affiliations: Centro Andaluz de Biología del Desarrollo,
Departamento de Ciencias Ambientales, Universidad Pablo de Olavide, Ctra.
Utrera, Km. 1, E-41013 Sevilla, Spain
Abstract: Ubiquinone (coenzyme Q, Q) is an essential lipid electron carrier in
the mitochondria respiratory chain, and also functions as antioxidant and
participates as a cofactor of mitochondrial uncoupling proteins.
Caernorhabditis elegans synthesize Q_9, but both dietary
Q_8intake and endogenous Q_9 biosynthesis
determine Q balance. Thus, it is of current interest to know the regulatory
mechanisms of Q_9 biosynthesis in this nematode. Here we
review results that leaded to identification of genes involved in
Q_9 biosynthesis in this nematode using the RNA interference
technology. C. elegans coq genes were silenced and depletion of Q content
was observed, indicating that the genes related here participate in
Q_9 biosynthesis. Silenced populations showed an extension
of adult life span, probably by the decrease of endogenous oxidative stress
produced in mitochondria. We also report the heterologous complementation of
C. elegans coq-5 and coq-7 genes in their homologue yeast coq
null mutants, leading to restore its ability to growth in non-fermentable
sugars. These complemented yeast strains accumulated Q_6 but
also the intermediate demethoxy-Q_6. These findings support
the conservative functional homology of these genes.
Keywords: coenzyme Q, aging, RNAi, superoxide, mitochondria
Journal: BioFactors, vol. 18, no. 1-4, pp. 237-244, 2003
