title: A phospholipid uptake system in the model plant Arabidopsis thaliana.
abstract: Plants use solar energy to produce lipids directly from inorganic elements and are not thought to require molecular systems for lipid uptake from the environment. Here we show that Arabidopsis thaliana Aminophospholipid ATPase10 (ALA10) is a P4-type ATPase flippase that internalizes exogenous phospholipids across the plasma membrane, after which they are rapidly metabolized. ALA10 expression and phospholipid uptake are high in the epidermal cells of the root tip and in guard cells, the latter of which regulate the size of stomatal apertures to modulate gas exchange. ALA10-knockout mutants exhibit reduced phospholipid uptake at the root tips and guard cells and are affected in growth and transpiration. The presence of a phospholipid uptake system in plants is surprising. Our results suggest that one possible physiological role of this system is to internalize lysophosphatidylcholine, a signalling lipid involved in root development and stomatal control.
authors.affiliation: Department of Plant and Environmental Sciences, Centre for Membrane Pumps in Cells and Disease-PUMPKIN, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark.
authors.forename: Lisbeth R
authors.initials: LR
authors.lastname: Poulsen
authors.affiliation: Department of Plant and Environmental Sciences, Centre for Membrane Pumps in Cells and Disease-PUMPKIN, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark.
authors.forename: Rosa L
authors.initials: RL
authors.lastname: López-Marqués
authors.affiliation: Department of Plant and Environmental Sciences, Centre for Membrane Pumps in Cells and Disease-PUMPKIN, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark.
authors.forename: Pai R
authors.initials: PR
authors.lastname: Pedas
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Nevada, Reno, 1664 N. Virginia Street-MS330, Reno, Nevada 89557, USA.
authors.forename: Stephen C
authors.initials: SC
authors.lastname: McDowell
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Nevada, Reno, 1664 N. Virginia Street-MS330, Reno, Nevada 89557, USA.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Brown
authors.affiliation: Dahlem Centre of Plant Sciences (DCPS), Freie Universität Berlin, Institut für Biologie - Angewandte Genetik, Albrecht-Thaer-Weg 6, D-14195 Berlin, Germany.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Kunze
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Nevada, Reno, 1664 N. Virginia Street-MS330, Reno, Nevada 89557, USA.
authors.forename: Jeffrey F
authors.initials: JF
authors.lastname: Harper
authors.affiliation: Department of Plant and Environmental Sciences, Centre for Membrane Pumps in Cells and Disease-PUMPKIN, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark.
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Pomorski
authors.affiliation: Department of Plant and Environmental Sciences, Centre for Membrane Pumps in Cells and Disease-PUMPKIN, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark.
authors.forename: Michael
authors.initials: M
authors.lastname: Palmgren
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics* / Q000378:metabolism; D017360:Arabidopsis; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D018519:Meristem / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D008861:Microsomes / Q000378:metabolism; D030781:Organisms, Genetically Modified; D049294:Phospholipid Transfer Proteins / Q000235:genetics* / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism*; D018515:Plant Leaves; D054046:Plant Stomata / Q000378:metabolism*; D012441:Saccharomyces cerevisiae; D014026:Nicotiana
chemical_list: D029681:Arabidopsis Proteins; D049294:Phospholipid Transfer Proteins; D010743:Phospholipids; D000251:Adenosine Triphosphatases; C000606653:ALA10 protein, Arabidopsis