TY  - JOUR
A1  - Dames, Petra
A1  - Zimmermann, Bernhard
A1  - Schmidt, Ruth
A1  - Rein, Julia
A1  - Voss, Martin
A1  - Schewe, Bettina
A1  - Walz, Bernd
A1  - Baumann, Otto
T1  - cAMP regulates plasma membrane vacuolar-type H+-ATPase assembly and activity in blowfly salivary glands
N2  - Reversible assembly of the V0V1 holoenzyme from V-0 and V-1 subcomplexes is a widely used mechanism for regulation of vacuolar-type H+-ATPases (V-ATPases) in animal cells. in the blowfly (Calliphora vicina) salivary gland, V- ATPase is located in the apical membrane of the secretory cells and energizes the secretion of a KCl-rich saliva in response to the hormone serotonin. We have examined whether the CAMP pathway, known to be activated by serotonin, controls V-ATPase assembly and activity. Fluorescence measurements of pH changes at the luminal surface of isolated glands demonstrate that CAMP, Sp-adenosine-3',5'-cyclic monophosphorothioate, or forskolin, similar to serotonin, cause V-ATPase-dependent luminal acidification. In addition, V-ATPase-dependent ATP hydrolysis increases upon treatment with these agents. Immunofluorescence microscopy and pelleting assays have demonstrated further that V, components become translocated from the cytoplasm to the apical membrane and V-ATPase holoenzymes are assembled at the apical membrane during conditions that increase intracellular cAMP. Because these actions occur without a change in cytosolic Ca2+, our findings suggest that the cAMP pathway mediates the reversible assembly and activation of V-ATPase molecules at the apical membrane upon hormonal stimulus
Y1  - 2006
UR  - http://www.pnas.org/
U6  - https://doi.org/10.1073/pnas.0600011103
SN  - 0027-8424
ER  -