Regulation of plasma membrane H + -ATPase activity by the members of the V-SNARE VAMP7C family in arabidopsis thaliana.

The plasma membrane (PM) H+ -ATPase plays an important role in response to environmental stress, such as salt-alkaline stress. We have reported that the N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) protein Vesicle-associated membrane protein 711 (VAMP711) is involved in drought stress by regulating PM H+ -ATPase activity directly. In this study, we report that VAMP7C (VAMP711-14) represses PM H+ -ATPase activity in response to high-pH stress. The Arabidopsis PM H+ -ATPase AHA2 interacts with VAMP7C. The longin domain of VAMP711 interacts with AHA2 to inhibit PM H+ -ATPase activity on the plasma membrane. The alkaline phenotype of vamp711 and vamp711 vamp712 vamp713 triple mutants suggested that VAMP7C was functionally redundant in regulating PM H+ -ATPase activity in response to high-pH stress.