title: Peroxisomal plant nitric oxide synthase (NOS) protein is imported by peroxisomal targeting signal type 2 (PTS2) in a process that depends on the cytosolic receptor PEX7 and calmodulin.
abstract: Nitric oxide (NO) production in plant peroxisomes by l-arginine-dependent NO synthase activity has been proven. The PEX5 and PEX7 PTS receptors, which recognize PTS1- and PTS2-containing proteins, are localized in the cytosol. Using AtPex5p and AtPex7p knockdown in Arabidopsis by RNA interference (RNAi) designated as pex5i and pex7i, we found that the l-arginine-dependent protein responsible for NO generation in peroxisomes appears to be imported through an N-terminal PTS2. Pharmacological analyzes using a calcium channel blocker and calmodulin (CaM) antagonist show that the import of the peroxisomal NOS protein also depends on calcium and calmodulin.
authors.affiliation: Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín, CSIC, Apartado 419, E-18080 Granada, Spain. Electronic address: javier.corpas@eez.csic.es.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Corpas
authors.affiliation: Group of Biochemistry and Cell Signaling in Nitric Oxide, Department of Biochemistry and Molecular Biology, University of Jaén, Campus "Las Lagunillas", E-23071 Jaén, Spain.
authors.forename: Juan B
authors.initials: JB
authors.lastname: Barroso
mesh_terms: D017360:Arabidopsis / Q000166:cytology* / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D002147:Calmodulin / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism*; D009154:Mutation; D009569:Nitric Oxide / Q000096:biosynthesis; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D000074437:Peroxisomal Targeting Signal 2 Receptor; D020675:Peroxisomes / Q000378:metabolism*; D021381:Protein Transport; D034622:RNA Interference; D018160:Receptors, Cytoplasmic and Nuclear / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D002147:Calmodulin; C000614267:PEX7 protein, Arabidopsis; D000074437:Peroxisomal Targeting Signal 2 Receptor; D018160:Receptors, Cytoplasmic and Nuclear; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D002118:Calcium
keywords: Arabidopsis thaliana; Nitric oxide; Nitric oxide synthase; Peroxin; Peroxisomal targeting signal; Peroxisome