TY  - JOUR
A1  - Fichtner, Franziska
A1  - Olas, Justyna Jadwiga
A1  - Feil, Regina
A1  - Watanabe, Mutsumi
A1  - Krause, Ursula
A1  - Hoefgen, Rainer
A1  - Stitt, Mark
A1  - Lunn, John Edward
T1  - Functional features of Trehalose-6-Phosphate Synthase 1
BT  - an essential enzyme in Arabidopsis
JF  - The Plant Cell
N2  - Tre6P synthesis by TPS1 is essential for embryogenesis and postembryonic growth in Arabidopsis, and appropriate Suc signaling by Tre6P is dependent on the noncatalytic domains of TPS1. In Arabidopsis (Arabidopsis thaliana), TREHALOSE-6-PHOSPHATE SYNTHASE1 (TPS1) catalyzes the synthesis of the sucrose-signaling metabolite trehalose 6-phosphate (Tre6P) and is essential for embryogenesis and normal postembryonic growth and development. To understand its molecular functions, we transformed the embryo-lethal tps1-1 null mutant with various forms of TPS1 and with a heterologous TPS (OtsA) from Escherichia coli, under the control of the TPS1 promoter, and tested for complementation. TPS1 protein localized predominantly in the phloem-loading zone and guard cells in leaves, root vasculature, and shoot apical meristem, implicating it in both local and systemic signaling of Suc status. The protein is targeted mainly to the nucleus. Restoring Tre6P synthesis was both necessary and sufficient to rescue the tps1-1 mutant through embryogenesis. However, postembryonic growth and the sucrose-Tre6P relationship were disrupted in some complementation lines. A point mutation (A119W) in the catalytic domain or truncating the C-terminal domain of TPS1 severely compromised growth. Despite having high Tre6P levels, these plants never flowered, possibly because Tre6P signaling was disrupted by two unidentified disaccharide-monophosphates that appeared in these plants. The noncatalytic domains of TPS1 ensure its targeting to the correct subcellular compartment and its catalytic fidelity and are required for appropriate signaling of Suc status by Tre6P.
KW  - cyanobacterial sucrose-phosphatase
KW  - trehalose 6-phosphate
KW  - vegetative growth
KW  - crystal-structure
KW  - gene-expression
KW  - thaliana
KW  - metabolism
KW  - phosphorylation
KW  - reveals
KW  - proteins
Y1  - 2020
U6  - https://doi.org/10.1105/tpc.19.00837
SN  - 0032-0781
SN  - 1471-9053
VL  - 32
IS  - 6
SP  - 1949
EP  - 1972
PB  - Oxford University Press
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Schmieder, Peter
A1  - Nitschke, Felix
A1  - Steup, Martin
A1  - Mallow, Keven
A1  - Specker, Edgar
T1  - Determination of glucan phosphorylation using heteronuclear H-1,C-13 double and H-1,C-13,P-31 triple-resonance NMR spectra
JF  - Magnetic resonance in chemistry
N2  - Phosphorylation and dephosphorylation of starch and glycogen are important for their physicochemical properties and also their physiological functions. It is therefore desirable to reliably determine the phosphorylation sites. Heteronuclear multidimensional NMR-spectroscopy is in principle a straightforward analytical approach even for complex carbohydrate molecules. With heterogeneous samples from natural sources, however, the task becomes more difficult because a full assignment of the resonances of the carbohydrates is impossible to obtain. Here, we show that the combination of heteronuclear H-1,C-13 and H-1,C-13,P-31 techniques and information derived from spectra of a set of reference compounds can lead to an unambiguous determination of the phosphorylation sites even in heterogeneous samples.
KW  - heteronuclear NMR
KW  - triple resonance
KW  - phosphorylation
KW  - starch
Y1  - 2013
U6  - https://doi.org/10.1002/mrc.3996
SN  - 0749-1581
VL  - 51
IS  - 10
SP  - 655
EP  - 661
PB  - Wiley-Blackwell
CY  - Hoboken
ER  -