The plasma membrane ATPase of plants and fungi is a hydrogen ion pump. The proton gradient it generates drives the active transport of nutrients by H(+)-symport. The resulting external acidification and/or internal alkinization may mediate growth responses. ATP + H(+)(in) + H2O = ADP + 2 H(+)(out) + phosphate Interacts with its cargot receptor EXP1 for its transport within the cell and maturation. Phosphorylated on multiple Ser and Thr residues. The prion state [GAR+] is provoked by the interaction of the two proteins STD1 and PMA1. It involves a complex between a small fraction of the cellular complement of PMA1, and STD1, a much lower-abundance protein, and it is transmissible by non-Mendelian, cytoplasmic inheritance. [GAR+] makes cells resistant to the glucose-associated repression of alternative carbon sources. In contrast to other prion forms, [GAR+] cannot be cured by GdnHCl or by inactivation of the molecular chaperone HSP104. There are two plasma membrane ATPases in yeast. This is the major isoform. Present with 1260000 molecules/cell in log phase SD medium. Belongs to the cation transport ATPase (P-type) (TC 3.A.3) family. Type IIIA subfamily.