Plasma membrane (PM) P2-type H+-ATPase; pumps protons out of the cell; major regulator of cytoplasmic pH and PM potential; long-lived hexameric protein asymmetrically distributed between mother cells and buds; buds emerge with very low levels of Pma1p, while newborn cells contain low levels, and mothers accumulate high levels during aging; has several calcium-binding sites in the nucleotide binding domain; regulated by Hsp30p; atypical yeast prion [GAR+] is derived from the Pma1p-Std1p complex