Functional analysis of Beta-ATP synthase as a lipophorin-binding protein in the midgut of Panstrongylus megistus (Hemiptera: Reduviidae)

FRUTTERO, L.L.; CARLINI, C.R.; RUBIOLO, E.R.; CANAVOSO, L.E.

La Falda, Córdoba.

Jornada; XIX Jornadas Científicas de la Sociedad de Biología de Córdoba; 2013

Sociedad de Biología de Córdoba

Lipophorin (Lp), the main insect lipoprotein, is a reusable shuttle that takes up or delivers lipids to tissues without being internalized and degraded. The process of lipid transfer involves the interaction of Lp with specific sites in the plasma membrane of the cells. Despite the relevance of this event in the physiology of the insects, the identification of non-endocytic Lp receptors is still lacking. The aim of this work was to characterize the role of the Beta subunit of the ATP synthase (Beta-ATPase) as an Lp-binding protein in the midgut as well as its involvement in the transfer of lipids. Fifth instar nymphs of Panstrongylus megistus, an important vector of Chagas´ disease, were used for the experiments. Ligand blotting followed by mass spectrometry allowed to identify the Beta-ATPase as an Lp-binding protein. After subcellular fractionation and western blot assays, Beta-ATPase was detected in cell membranes. The immunofluorescence analysis evidenced co-localization of Beta-ATPase and Lp in the membrane of midgut cells. Functional in vivo studies injecting anti-Beta-ATPase to block the Lp-Beta-ATPase interaction resulted in an important inhibition of the lipid transfer from Lp to the midgut. Taken together, these findings supported the role of Beta-ATPase as a non-endocytic Lp receptor in the midgut of P. megistus.