InterPro domain: IPR029669

This entry represents a group of plant proton pump-interactors, which may regulate plasma membrane ATPase activity. In Arabidopsis, proton pump-interactor 1 (PPI1, At4g27500) interacts with the C-terminal autoinhibitory domain of the membrane (PM) H(+)-ATPase [ 1 ]. It promotes plasma membrane ATPase (AHA1 isoform) activity by binding to a site different from the 14-3-3 binding site [ 2 ]. It is localised at the endoplasmic reticulum, from which it might be recruited to the plasma membrane [ 2 ].

1. Characterization of the interaction between the plasma membrane H-ATPase of Arabidopsis thaliana and a novel interactor (PPI1). FEBS J. 272, 5864-71
2. Intracellular localisation of PPI1 (proton pump interactor, isoform 1), a regulatory protein of the plasma membrane H(+)-ATPase of Arabidopsis thaliana. Plant Biol (Stuttg) 11, 869-77