Catabolite inactivation of the high‐affinity hexose transporters Hxt6 and Hxt7 of Saccharomyces cerevisiae occurs in the vacuole after internalization by endocytosis 1

FEBS Letters

Boles, Eckhard¹  Stamm, Olaf¹  Krampe, Stefanie¹  Hollenberg, Cornelis P¹ 

[1] Institut für Mikrobiologie, Heinrich-Heine-Universität, Universitätsstr. 1, Geb. 26.12.01, D-40225 Düsseldorf, Germany

关键词: Sugar transport;    Glucose;    Endocytosis;    Vacuole;    Ubiquitination;    Yeast;   

DOI  :  10.1016/S0014-5793(98)01583-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

After addition of high concentrations of glucose, rates of high-affinity glucose uptake in Saccharomyces cerevisiae decrease rapidly. We found that the high-affinity hexose transporters Hxt6 and Hxt7 are subject to glucose-induced proteolytic degradation (catabolite inactivation). Degradation occurs in the vacuole, as Hxt6/7 were stabilized in proteinase A-deficient mutant cells. Degradation was independent of the proteasome. The half-life of Hxt6 and Hxt7 strongly increased in end4, ren1 and act1 mutant strains, indicating that the proteins are delivered to the vacuole by endocytosis. Moreover, both proteins were also stabilized in mutants defective in ubiquitination. However, the initial signal that triggers catabolite inactivation is not relayed via the glucose sensors Snf3 and Rgt2.

【 授权许可】

Unknown