Protein kinase A-dependent and -independent activation of the V-ATPase in Malpighian tubules of Aedes aegypti

F. Tiburcy, K. W. Beyenbach, H. Wieczorek
2012 Journal of Experimental Biology  
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
more » ... d activate ATP-dependent transport processes. In parallel, membrane association of the V 1 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.
doi:10.1242/jeb.078360 pmid:23197085 fatcat:l2gxdksz5vewham6j4brv6suzq