title: A dual-targeted purple acid phosphatase in Arabidopsis thaliana moderates carbon metabolism and its overexpression leads to faster plant growth and higher seed yield.
abstract: • Overexpression of AtPAP2, a purple acid phosphatase (PAP) with a unique C-terminal hydrophobic motif in Arabidopsis, resulted in earlier bolting and a higher seed yield. Metabolite analysis showed that the shoots of AtPAP2 overexpression lines contained higher levels of sugars and tricarboxylic acid (TCA) metabolites. Enzyme assays showed that sucrose phosphate synthase (SPS) activity was significantly upregulated in the overexpression lines. The higher SPS activity arose from a higher level of SPS protein, and was independent of SnRK1. • AtPAP2 was found to be targeted to both plastids and mitochondria via its C-terminal hydrophobic motif. Ectopic expression of a truncated AtPAP2 without this C-terminal motif in Arabidopsis indicated that the subcellular localization of AtPAP2 is essential for its biological actions. • Plant PAPs are generally considered to mediate phosphorus acquisition and redistribution. AtPAP2 is the first PAP shown to modulate carbon metabolism and the first shown to be dual-targeted to both plastids and mitochondria by a C-terminal targeting signal. • One PAP-like sequence carrying a hydrophobic C-terminal motif could be identified in the genome of the smallest free-living photosynthetic eukaryote, Ostreococcus tauri. This might reflect a common ancestral function of AtPAP2-like sequences in the regulation of carbon metabolism.
authors.affiliation: School of Biological Sciences, the University of Hong Kong, Pokfulam, Hong Kong, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Sun
authors.affiliation: School of Biological Sciences, the University of Hong Kong, Pokfulam, Hong Kong, China.
authors.forename: Pui Kit
authors.initials: PK
authors.lastname: Suen
authors.affiliation: School of Biological Sciences, the University of Hong Kong, Pokfulam, Hong Kong, China.
authors.forename: Youjun
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: School of Biological Sciences, the University of Hong Kong, Pokfulam, Hong Kong, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Liang
authors.affiliation: Australian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley WA 6009, Australia.
authors.forename: Chris
authors.initials: C
authors.lastname: Carrie
authors.affiliation: Australian Research Council Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley WA 6009, Australia.
authors.forename: James
authors.initials: J
authors.lastname: Whelan
authors.affiliation: National Centre for Plant and Microbial Metabolomics, Rothamsted Research, West Common, Harpenden, Herts, AL5 2JQ, UK.
authors.forename: Jane L
authors.initials: JL
authors.lastname: Ward
authors.affiliation: National Centre for Plant and Microbial Metabolomics, Rothamsted Research, West Common, Harpenden, Herts, AL5 2JQ, UK.
authors.forename: Nathaniel D
authors.initials: ND
authors.lastname: Hawkins
authors.affiliation: School of Life Sciences, Centre for Cell and Developmental Biology, the Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Liwen
authors.initials: L
authors.lastname: Jiang
authors.affiliation: School of Biological Sciences, the University of Hong Kong, Pokfulam, Hong Kong, China.
authors.forename: Boon Leong
authors.initials: BL
authors.lastname: Lim
mesh_terms: D000135:Acid Phosphatase / Q000737:chemistry / Q000378:metabolism*; D020816:Amino Acid Motifs; D017360:Arabidopsis / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000378:metabolism*; D015153:Blotting, Western; D002241:Carbohydrates / Q000494:pharmacology; D002244:Carbon / Q000378:metabolism*; D002736:Chloroplasts / Q000187:drug effects / Q000378:metabolism; D017124:Conserved Sequence; D004269:DNA, Bacterial / Q000235:genetics; D057075:Enzyme Assays; D006023:Glycoproteins / Q000737:chemistry / Q000378:metabolism*; D057927:Hydrophobic and Hydrophilic Interactions / Q000187:drug effects; D055432:Metabolomics; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D008954:Models, Biological; D010641:Phenotype; D010758:Phosphorus / Q000494:pharmacology; D010788:Photosynthesis / Q000187:drug effects; D030821:Plants, Genetically Modified; D018087:Plastids / Q000187:drug effects / Q000378:metabolism; D021381:Protein Transport / Q000187:drug effects; D012639:Seeds / Q000187:drug effects / Q000254:growth & development*; D012995:Solubility / Q000187:drug effects
chemical_list: D029681:Arabidopsis Proteins; D002241:Carbohydrates; D004269:DNA, Bacterial; D006023:Glycoproteins; C036483:T-DNA; D010758:Phosphorus; D002244:Carbon; C091137:purple acid phosphatase; D000135:Acid Phosphatase