title: Dynamics and environmental responses of PATROL1 in Arabidopsis subsidiary cells.
abstract: The Arabidopsis stomatal complex is composed of a pair of guard cells and surrounding anisocytic subsidiary cells. Subsidiary cells are thought to function as a supplier and receiver of bulk water and ions, and to assist turgor-driven stomatal movement, but the molecular mechanisms are largely unknown. In this work, we studied the dynamic behavior and environmental responses of PATROL1, which has been identified as a translocation factor of the plasma membrane proton pump ATPase (PM H(+)-ATPase) AHA1 in guard cells and subsidiary cells in Arabidopsis thaliana. Variable-angle epifluorescence microscopic observation revealed that green fluorescent protein (GFP)-PATROL1 localized on dot-like compartments that resided on plasma membranes for several seconds. The GFP-PATROL1-labeled dots were sensitive to phosphatidylinositol 4-kinase inhibitors but not to a phosphatidylinositol 3-kinase inhibitor. GFP-PATROL1 and red fluorescent protein (RFP)-AHA1 co-localized in hyperosmotic conditions, and a mutation of PATROL1 resulted in an increase in GFP-AHA1 internalization, suggesting a role in the translocation of PM H(+)-ATPase in subsidiary cells. Interestingly, subsidiary cells showed changes in localization of GFP-PATROL1 in response to environmental stimuli that were opposite to those in guard cells. Our observations suggested that PATROL1 may contribute to stomatal movement by translocations of PM H(+)-ATPase in subsidiary cells.
authors.affiliation: Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwanoha, Kashiwa, Chiba, 277-8562 Japan.
authors.forename: Takumi
authors.initials: T
authors.lastname: Higaki
authors.forename: Mimi
authors.initials: M
authors.lastname: Hashimoto-Sugimoto
authors.forename: Kae
authors.initials: K
authors.lastname: Akita
authors.forename: Koh
authors.initials: K
authors.lastname: Iba
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Hasezawa
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D017360:Arabidopsis / Q000166:cytology* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D004777:Environment; D049452:Green Fluorescent Proteins / Q000378:metabolism; D015778:Minor Histocompatibility Antigens; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000037:antagonists & inhibitors / Q000378:metabolism; D054046:Plant Stomata / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D021381:Protein Transport / Q000187:drug effects; D006180:Proton-Translocating ATPases / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D015778:Minor Histocompatibility Antigens; C585961:PATROL1 protein, Arabidopsis; D047428:Protein Kinase Inhibitors; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D000040:Abscisic Acid; D017853:Phosphotransferases (Alcohol Group Acceptor); C402182:phosphatidylinositol phosphate 4-kinase; D006180:Proton-Translocating ATPases; C544444:AHA1 protein, Arabidopsis
keywords: ABA; PATROL1; Proton pump ATPase; Stomata; Subsidiary cells; Variable-angle epifluorescence microscopy