title: Trehalose-6-phosphate synthase 1 is not the only active TPS in Arabidopsis thaliana.
abstract: Trehalose metabolism is essential for normal growth and development in higher plants. It is synthesized in a two-step pathway catalysed by TPS (trehalose-6-phosphate synthase) and trehalose phosphatase. Arabidopsis thaliana has 11 TPS or TPS-like proteins, which belong to two distinct clades: class I (AtTPS1-AtTPS4) and class II (AtTPS5-AtTPS11). Only AtTPS1 has previously been shown to have TPS activity. A. thaliana tps1∆ mutants fail to complete embryogenesis and rescued lines have stunted growth and delayed flowering, indicating that AtTPS1 is important throughout the life cycle. In the present study, we show that expression of AtTPS2 or AtTPS4 enables the yeast tps1∆ tps2∆ mutant to grow on glucose and accumulate Tre6P (trehalose 6-phosphate) and trehalose. Class II TPS genes did not complement the yeast mutant. Thus A. thaliana has at least three catalytically active TPS isoforms, suggesting that loss of Tre6P production might not be the only reason for the growth defects of A. thaliana tps1 mutants.
authors.affiliation: *Department of Molecular Microbiology, VIB, KU Leuven, 3001 Leuven, Belgium.
authors.forename: Ines
authors.initials: I
authors.lastname: Delorge
authors.affiliation: ‡Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany.
authors.forename: Carlos M
authors.initials: CM
authors.lastname: Figueroa
authors.affiliation: ‡Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany.
authors.forename: Regina
authors.initials: R
authors.lastname: Feil
authors.affiliation: ‡Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany.
authors.forename: John E
authors.initials: JE
authors.lastname: Lunn
authors.affiliation: *Department of Molecular Microbiology, VIB, KU Leuven, 3001 Leuven, Belgium.
authors.forename: Patrick
authors.initials: P
authors.lastname: Van Dijck
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017124:Conserved Sequence; D005964:Glucosyltransferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D007527:Isoenzymes / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000737:chemistry / Q000378:metabolism; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D013403:Sugar Phosphates / Q000378:metabolism; D014199:Trehalose / Q000031:analogs & derivatives / Q000378:metabolism; D020798:Two-Hybrid System Techniques
chemical_list: D029681:Arabidopsis Proteins; D007527:Isoenzymes; D050505:Mutant Proteins; D011994:Recombinant Proteins; D013403:Sugar Phosphates; C082722:trehalose-6-phosphate; D014199:Trehalose; D005964:Glucosyltransferases; C023180:trehalose-6-phosphate synthase