Protein kinase A-dependent and -independent activation of the V-ATPase in Malpighian tubules of Aedes aegypti
Autor(en): | Tiburcy, Felix Beyenbach, Klaus W. Wieczorek, Helmut |
Stichwörter: | Aedes aegypti; APICAL MEMBRANE; Biology; BLOWFLY SALIVARY-GLANDS; cAMP; DROSOPHILA-MELANOGASTER; EPITHELIAL TRANSPORT; FLUID SECRETION; INTRACELLULAR PH REGULATION; Life Sciences & Biomedicine - Other Topics; Malpighian tubule; PLASMA-MEMBRANE; protein kinase A; TOBACCO HORNWORM MIDGUT; V-ATPase activity; VACUOLAR H+-ATPASE; YELLOW-FEVER MOSQUITO | Erscheinungsdatum: | 2013 | Herausgeber: | COMPANY OF BIOLOGISTS LTD | Journal: | JOURNAL OF EXPERIMENTAL BIOLOGY | Volumen: | 216 | Ausgabe: | 5 | Startseite: | 881 | Seitenende: | 891 | Zusammenfassung: | 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 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. |
ISSN: | 00220949 | DOI: | 10.1242/jeb.078360 |
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