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

Waltraud Schulze, Andreas Weise, Wolf B. Frommer, John M. Ward

Research output: Contribution to journalArticlepeer-review

69 Scopus citations

Abstract

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.

Original languageEnglish (US)
Pages (from-to)189-194
Number of pages6
JournalFEBS Letters
Volume485
Issue number2-3
DOIs
StatePublished - Nov 24 2000

Keywords

  • Protein chimera
  • Sucrose sensor
  • Sucrose transporter

Fingerprint Dive into the research topics of 'Function of the cytosolic N-terminus of sucrose transporter AtSUT2 in substrate affinity'. Together they form a unique fingerprint.

Cite this