TY  - JOUR
A1  - Malinova, Irina
A1  - Mahto, Harendra
A1  - Brandt, Felix
A1  - AL-Rawi, Shadha
A1  - Qasim, Hadeel
A1  - Brust, Henrike
A1  - Hejazi, Mahdi
A1  - Fettke, Jörg
T1  - EARLY STARVATION1 specifically affects the phosphorylation action of starch-related dikinases
JF  - The plant journal
N2  - Starch phosphorylation by starch-related dikinases glucan, water dikinase (GWD) and phosphoglucan, water dikinase (PWD) is a key step in starch degradation. Little information is known about the precise structure of the glucan substrate utilized by the dikinases and about the mechanisms by which these structures may be influenced. A 50-kDa starch-binding protein named EARLY STARVATION1 (ESV1) was analyzed regarding its impact on starch phosphorylation. In various invitro assays, the influences of the recombinant protein ESV1 on the actions of GWD and PWD on the surfaces of native starch granules were analyzed. In addition, we included starches from various sources as well as truncated forms of GWD. ESV1 preferentially binds to highly ordered, -glucans, such as starch and crystalline maltodextrins. Furthermore, ESV1 specifically influences the action of GWD and PWD at the starch granule surface. Starch phosphorylation by GWD is decreased in the presence of ESV1, whereas the action of PWD increases in the presence of ESV1. The unique alterations observed in starch phosphorylation by the two dikinases are discussed in regard to altered glucan structures at the starch granule surface.
KW  - Arabidopsis thaliana
KW  - EARLY STARVATION1
KW  - glucan
KW  - phosphoglucan
KW  - starch granule surface
KW  - starch phosphorylation
KW  - water dikinase
Y1  - 2018
U6  - https://doi.org/10.1111/tpj.13937
SN  - 0960-7412
SN  - 1365-313X
VL  - 95
IS  - 1
SP  - 126
EP  - 137
PB  - Wiley
CY  - Hoboken
ER  -