BIOSYNTHESIS OF LIPOIC ACID IN THE NEMATODE Caenorhabditis elegans

LAVATELLI, A; DE MENDOZA, D; MANSILLA, MC

Mar del Plata

Congreso; LI Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2015

SAIB

Lipoic acid (LA) is asulfur-containing cofactor derived from octanoic acid that is required for thefunction of several multienzymes complexes involved in oxidative and one-carbonmetabolism. It is also a potent antioxidant. As the information concerning LAmetabolism in eukaryotes is scarce, we initiated the use of Caenorhabditiselegans as a modelorganism to study it. By in silico analyses we found several wormenzymes possibly involved in lipoylation. We have already shown that a block ofthe expression of M01F1.3, an homolog to the bacterial and yeast lipoate synthases,by RNA interference (RNAi) caused a development arrest at L4 larvae of theanimals of the second generation. Using Western blot assays with anti-LAantibodies we proved that the treated worms showed reduced levels of proteinlipoylation than the controls, confirming that M01F1.3 is involved in lipoatemetabolism. The addition of neither free LA nor the products of the lipoylatedenzymes reverted the phenotype, which lead us to think that synthesis of LA isessential in the worm. RNAi experiments against the others proteins possiblyinvolved in LA metabolism were also performed, but no abnormal phenotype wasobserved. Mutant yeasts in LA biosynthesis were constructed to performcomplementation assays, in order to confirm if the worm proteins identified byhomology searches are indeed involved in lipoylation.