Roles of plasma membrane proton ATPases AHA2 and AHA7 in normal growth of roots and root hairs in Arabidopsis thaliana.

ABSTRACT: Plasma membrane H⁺ -ATPase pumps build up the electrochemical H⁺ gradients that energize most other transport processes into and out of plant cells through channel proteins and secondary active carriers. In Arabidopsis thaliana, the AUTOINHIBITED PLASMA MEMBRANE H⁺ -ATPases AHA1, AHA2 and AHA7 are predominant in root epidermal cells. In contrast to other H⁺ -ATPases, we find that AHA7 is autoinhibited by a sequence present in the extracellular loop between transmembrane segments 7 and 8. Autoinhibition of pump activity was regulated by extracellular pH, suggesting negative feedback regulation of AHA7 during establishment of an H⁺ gradient. Due to genetic redundancy, it has proven difficult to test the role of AHA2 and AHA7, and mutant

SUBMITTER: Hoffmann RD 

PROVIDER: S-EPMC7379730 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature