Plasma Membrane H + -ATPase Regulation in the Center of Plant Physiology

Abstract

The plasma membrane (PM) H(+)-ATPase is an important ion pump in the plant cell membrane. By extruding protons from the cell and generating a membrane potential, this pump energizes the PM, which is a prerequisite for growth. Modification of the autoinhibitory terminal domains activates PM H(+)-ATPase activity, and on this basis it has been hypothesized that these regulatory termini are targets for physiological factors that activate or inhibit proton pumping. In this review, we focus on the posttranslational regulation of the PM H(+)-ATPase and place regulation of the pump in an evolutionary and physiological context. The emerging picture is that multiple signals regulating plant growth interfere with the posttranslational regulation of the PM H(+)-ATPase.

Early mannitol-triggered changes in the Arabidopsis leaf (phospho)proteome reveal growth regulators

“…Thr881 is situated in the conserved autoinhibitory region I of the C-terminal domain of AHA2 (Rudashevskaya et al , 2012; Falhof et al , 2016), and rapid PLANT PEPTIDE CONTAINING SULFATED TYROSINE 1 (PSY1)-induced in planta phosphorylation of AHA2 at Thr881 increases proton efflux (Fuglsang et al , 2014). To assess the role of AHA2 in growth inhibition upon mild osmotic stress, we characterized the strong knock-down aha2-4 mutant with only ~10% AHA2 expression compared to the wild type (Haruta et al , 2010).…”

Cellulose Synthesis and Cell Expansion Are Regulated by Different Mechanisms in Growing Arabidopsis Hypocotyls

“…Cell wall acidification mediated by plasma membrane H + -ATPases (Falhof et al, 2016) stimulates expansins due to their low-pH optima (Cosgrove, 2016b) and is also the driving force for solute uptake to generate cell turgor.…”

Proton pump and plant cell elongation

“…It was suggested that the activation of MHA1 occurs by another mechanism, or this isoform has another binding site for 14-3-3 proteins (Portillo, 2000). The protein kinase responsible for the phosphorylation of Thr947 H + -ATPase has not yet been identified (Gaxiola, Palmgren, and Schumacher, 2007;Falhof, Pedersen, Fuglsang, and Palmgren, 2016). Recently additional sites of phosphorylation have been revealed (Rudashevskaya et al, 2012;Haruta, Gray, and Sussman, 2015;Falhof, Pedersen, Fuglsang, and Palmgren, 2016).…”

“…The protein kinase responsible for the phosphorylation of Thr947 H + -ATPase has not yet been identified (Gaxiola, Palmgren, and Schumacher, 2007;Falhof, Pedersen, Fuglsang, and Palmgren, 2016). Recently additional sites of phosphorylation have been revealed (Rudashevskaya et al, 2012;Haruta, Gray, and Sussman, 2015;Falhof, Pedersen, Fuglsang, and Palmgren, 2016). Among those sites were Ser-899, Ser-904 and Ser-931 residues in AHA1 and AHA2 proteins of Arabidopsis.…”