Protein kinase A-dependent and -independent activation of the V-ATPase in Malpighian tubules of Aedes aegypti
Autor(es): Tiburcy, Felix; Beyenbach, Klaus W.; Wieczorek, Helmut
Resumo: Transepithelial ion transport in insect Malpighian tubules is energized by an apical V-ATPase. In hematophagous insects, a blood meal during which the animal ingests huge amounts of salt and water stimulates transepithelial transport processes linked to V-ATPase activation, but how this is accomplished is still unclear. Here we report that membrane-permeant derivatives of cAMP increase the bafilomycin-sensitive ATPase activity in Malpighian tubules of Aedes aegypti twofold and activate ATP-dependent transport processes. In parallel, membrane association of the V1 subunits C and D increases, consistent with the assembly of the holoenzyme. The protein kinase A inhibitor H-89 abolishes all cAMP-induced effects, consistent with protein kinase A (PKA) being involved in V-ATPase activation. Metabolic inhibition induced by KCN, azide and 2,4-dinitrophenol, respectively, also induces assembly of functional V-ATPases at the membrane without PKA involvement, indicating a phosphorylation-independent activation mechanism.
Palavras-Chave: Ion transport; Salt advection; Proteins; Inhibitors; Transport processes; Aquatic insects; Public health; Salts; Protein kinase A; Adenosinetriphosphatase; Protein kinase A inhibitors; Malpighian tubules; Cyclic AMP; Metabolic rate; Blood meals; Aedes aegypti
Imprenta: Journal of Experimental Biology, v. 216, n. 5, p. 881-891, 2013.
Descritores: Aedes aegypti - Proteins ; Aedes aegypti - Public health
Data de publicação: 2013
