INVESTIGADORES
ALVAREZ Hector Manuel
congresos y reuniones científicas
Título:
Identification of a novel lipid ABC transporter of Rhodococcus jostii RHA1 and its role in triacylglycerols accumulation
Autor/es:
ALVAREZ HM; VILLALBA MS
Lugar:
Montpellier
Reunión:
Congreso; 12th Euro Fed Lipid Congress (Oils, Fats and Lipids: from Lipidomics to Industrial Innovation); 2014
Institución organizadora:
Euro Fed Lipid
Resumen:
Rhodococcus jostii RHA1 is able to synthesize and accumulate significant amounts of triacylglycerols (TAG). We performed a broad survey of genes coding for putative lipid transporter proteins, since no transporter related with TAG metabolism has been characterized until now in these oleaginous bacteria. Among seven putative transporters, a gene (ro05645) (called ltp1: lipid transporter protein) coding for an ABC protein is clustered with other genes encoding putative enzymes catalyzing the three acylation reactions of the Kennedy pathway for TAG synthesis. Overexpression of ro05645) gene in strain RHA1 led to an increase of approximately six- and three-folds in biomass and TAG production; respectively, when cells were cultivated on palmitic acid and oleic acid. Moreover, gene overexpression promoted a significant increase in the uptake of the fluorescently labeled long chain fatty acid in comparison to the wild type, and its incorporation into phospholipids, diacylglycerols and TAG fractions. Gluconate-grown cells showed increasing amounts of intracellular free fatty acids, but not of TAG, after overexpressing ltp1 gene. Thus, for the first time, a transporter functionally related to TAG metabolism was identified in oleaginous rhodococci. Our results suggest that Ltp1 is an importer of long chain fatty acids, which plays a functional role in lipid homeostasis of R. jostii RHA1. In this context, Ltp1 transporter may contribute with the fatty acid recycling, managing of membrane and envelope lipids, and the maintenance of internal fatty acids pools for the production of a large variety of lipids with different complexity and functions.