The flip side of the Arabidopsis type I proton-pumping pyrophosphatase (AVP1): Using a transmembrane H⁺ gradient to synthesize pyrophosphate.

ABSTRACT: Energy partitioning and plant growth are mediated in part by a type I H⁺-pumping pyrophosphatase (H⁺-PPase). A canonical role for this transporter has been demonstrated at the tonoplast where it serves a job-sharing role with V-ATPase in vacuolar acidification. Here, we investigated whether the plant H⁺-PPase from Arabidopsis also functions in "reverse mode" to synthesize PP_i using the transmembrane H⁺ gradient. Using patch-clamp recordings on Arabidopsis vacuoles, we observed inward currents upon P_i application on the cytosolic side. These currents were strongly reduced in vacuoles from two independent H⁺-PPase mutant lines (vhp1-1 and fugu5-1) lacking the classical PP_i-indu

SUBMITTER: Scholz-Starke J 

PROVIDER: S-EPMC6349097 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature