title: Characterization of the plastidic phosphate translocators in the inducible crassulacean acid metabolism plant Mesembryanthemum crystallinum.
abstract: In plant Mesembryanthemum crystallinum, which has the inducible crassulacean acid metabolism (CAM), isoforms of plastidic phosphate translocators (pPTs) are categorized into three subfamilies: the triose phosphate/phosphate translocator (McTPT1), the phosphoenolpyruvate/phosphate translocator (McPPT1), and the glucose 6-phosphate/phosphate translocator (McGPT1 and McGPT2). In order to elucidate the physiological roles of these pPTs in M. crystallinum, we determined the substrate specificity of each pPT isoform. The substrate specificities of McTPT1, McPPT1, and McGPT1 showed overall similarities to those of orthologs that have been characterized. In contrast, for glucose 6-phosphate, McGPT2 showed higher selectivity than McGPT1 and other GPT orthologs. Because the expression of McGTP2 is specific to CAM while that of McGTP1 is constitutively expressed in both the C3- and the CAM-state in M. crystallinum, we propose that McGPT2 functions as a CAM system-specific GPT in this plant.
authors.affiliation: Comprehensive Analysis Center for Science, Saitama University, Saitama, Saitama 338-8570, Japan.
authors.forename: Shin
authors.initials: S
authors.lastname: Kore-eda
authors.forename: Akira
authors.initials: A
authors.lastname: Nozawa
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Okada
authors.forename: Kazuki
authors.initials: K
authors.lastname: Takashi
authors.forename: Muhammad Abul Kalam
authors.initials: MA
authors.lastname: Azad
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Ohnishi
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Nishiyama
authors.forename: Yuzuru
authors.initials: Y
authors.lastname: Tozawa
mesh_terms: D007700:Kinetics; D026901:Membrane Transport Proteins / Q000378:metabolism*; D035723:Mesembryanthemum / Q000166:cytology* / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism*; D010788:Photosynthesis; D010802:Phylogeny; D018087:Plastids / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D026901:Membrane Transport Proteins; D010710:Phosphates