title: POLYAMINE OXIDASE 1 from rice (Oryza sativa) is a functional ortholog of Arabidopsis POLYAMINE OXIDASE 5.
abstract: POLYAMINE OXIDASE 1 (OsPAO1), from rice (Oryza sativa), and POLYAMINE OXIDASE 5 (AtPAO5), from Arabidopsis (Arabidopsis thaliana), are enzymes sharing high identity at the amino acid level and with similar characteristics, such as polyamine specificity and pH preference; furthermore, both proteins localize to the cytosol. A loss-of-function Arabidopsis mutant, Atpao5-2, was hypersensitive to low doses of exogenous thermospermine but this phenotype could be rescued by introduction of the wild-type AtPAO5 gene. Introduction of OsPAO1, under the control of a constitutive promoter, into Atpao5-2 mutants also restored normal thermospermine sensitivity, allowing growth in the presence of low levels of thermospermine, along with a concomitant decrease in thermospermine content in plants. By contrast, introduction of OsPAO3, which encodes a peroxisome-localized polyamine oxidase, into Atpao5-2 plants could not rescue any of the mutant phenotypes in the presence of thermospermine. These results suggest that OsPAO1 is the functional ortholog of AtPAO5.
authors.affiliation: a Graduate School of Life Sciences; Tohoku University; Sendai, Miyagi, Japan.
authors.forename: Taibo
authors.initials: T
authors.lastname: Liu
authors.forename: Dong
authors.initials: D
authors.lastname: Wook Kim
authors.forename: Masaru
authors.initials: M
authors.lastname: Niitsu
authors.forename: Thomas
authors.initials: T
authors.lastname: Berberich
authors.forename: Tomonobu
authors.initials: T
authors.lastname: Kusano
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017343:Genes, Plant; D005816:Genetic Complementation Test; D008958:Models, Molecular; D009154:Mutation; D012275:Oryza / Q000201:enzymology* / Q000235:genetics; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D017434:Protein Structure, Tertiary; D040681:Structural Homology, Protein; D000097667:Polyamine Oxidase
chemical_list: D029681:Arabidopsis Proteins; D000587:Oxidoreductases Acting on CH-NH Group Donors; D010940:Plant Proteins; D000097667:Polyamine Oxidase
keywords: Arabidopsis thaliana; AtPAO5; Oryza sativa; OsPAO1; polyamine oxidase; thermospermine