title: Receptor kinase-mediated control of primary active proton pumping at the plasma membrane.
abstract: Acidification of the cell wall space outside the plasma membrane is required for plant growth and is the result of proton extrusion by the plasma membrane-localized H+-ATPases. Here we show that the major plasma membrane proton pumps in Arabidopsis, AHA1 and AHA2, interact directly in vitro and in planta with PSY1R, a receptor kinase of the plasma membrane that serves as a receptor for the peptide growth hormone PSY1. The intracellular protein kinase domain of PSY1R phosphorylates AHA2/AHA1 at Thr-881, situated in the autoinhibitory region I of the C-terminal domain. When expressed in a yeast heterologous expression system, the introduction of a negative charge at this position caused pump activation. Application of PSY1 to plant seedlings induced rapid in planta phosphorylation at Thr-881, concomitant with an instantaneous increase in proton efflux from roots. The direct interaction between AHA2 and PSY1R observed might provide a general paradigm for regulation of plasma membrane proton transport by receptor kinases.
authors.affiliation: Department of Plant and Environmental Science, Center for Membrane Pumps in Cells and Disease - PUMPKIN, Danish National Research Foundation, University of Copenhagen, DK-1871, Frederiksberg, Denmark.
authors.forename: Anja T
authors.initials: AT
authors.lastname: Fuglsang
authors.forename: Astrid
authors.initials: A
authors.lastname: Kristensen
authors.forename: Tracey A
authors.initials: TA
authors.lastname: Cuin
authors.forename: Waltraud X
authors.initials: WX
authors.lastname: Schulze
authors.forename: Jörgen
authors.initials: J
authors.lastname: Persson
authors.forename: Kristina H
authors.initials: KH
authors.lastname: Thuesen
authors.forename: Cecilie K
authors.initials: CK
authors.lastname: Ytting
authors.forename: Christian B
authors.initials: CB
authors.lastname: Oehlenschlæger
authors.forename: Khalid
authors.initials: K
authors.lastname: Mahmood
authors.forename: Teis E
authors.initials: TE
authors.lastname: Sondergaard
authors.forename: Sergey
authors.initials: S
authors.lastname: Shabala
authors.forename: Michael G
authors.initials: MG
authors.lastname: Palmgren
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002473:Cell Wall / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D010766:Phosphorylation; D018517:Plant Roots / Q000201:enzymology / Q000235:genetics; D006180:Proton-Translocating ATPases / Q000235:genetics / Q000378:metabolism*; D018000:Receptors, Peptide / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D036226:Seedlings / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; C000588888:PSY1R protein, Arabidopsis; D018000:Receptors, Peptide; D006180:Proton-Translocating ATPases; C544444:AHA1 protein, Arabidopsis; C479903:AHA2 protein, Arabidopsis
keywords: H+ pump; LRR kinase; apoplastic pH; cell elongation; peptide signalling