The plasma membrane H(+) ATPase of plants and fungi generates a proton gradient that drives the active transport of nutrients by H(+)-symport. The resulting external acidification and/or internal alkinization may mediate growth responses (By similarity). ATP + H(+)(in) + H2O = ADP + 2 H(+)(out) + phosphate Binds to 14-3-3 proteins. The binding is induced by phosphorylation of Thr-947. Binding to 14-3-3 proteins activates the H(+)-ATPase (By similarity). Belongs to the cation transport ATPase (P-type) (TC 3.A.3) family. Type IIIA subfamily.