Function of the cytosolic N-terminus of sucrose transporter AtSUT2 in substrate affinity

被引：70

作者：

Schulze, W ^{[1
]}

Weise, A ^{[1
]}

Frommer, WB ^{[1
]}

Ward, JM ^{[1
]}

机构：

[1] Univ Tubingen, ZMBP, D-72076 Tubingen, Germany

来源：

FEBS LETTERS | 2000年 / 485卷 / 2-3期

关键词：

sucrose transporter; sucrose sensor; protein chimera;

D O I：

10.1016/S0014-5793(00)02180-3

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

AtSUT2 was found to be a low-affinity sucrose transporter (K-M = 11.7 mM at pH 4), Chimeric proteins between AtSUT2 and the high-affinity StSUT1 were constructed in which the extended N-terminus and central loop of AtSUT2 were exchanged with those domains of StSUT1 and vice versa. Chimeras containing the N-terminus of AtSUT2 showed significantly lower affinity for sucrose compared to chimeras containing the N-terminus of StSUT1, The results indicate a significant function of the N-terminus but not the central cytoplasmic loop in determining substrate affinity. Expression of AtSUT2 in major veins of source leaves and in flowers is compatible with a role as a second low-affinity sucrose transporter or as a sucrose sensor. (C) 2000 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.

引用

页码：189 / 194

页数：6

共 33 条

[1] ISOLATION OF YEAST MUTANTS DEFECTIVE IN PROTEIN TARGETING TO THE VACUOLE [J].