Degradation of the hexose transporter Hxt5p in Saccharomyces cerevisiae

Details

Serval ID
serval:BIB_EC4CC79ACD94
Type
Article: article from journal or magazin.
Collection
Publications
Title
Degradation of the hexose transporter Hxt5p in Saccharomyces cerevisiae
Journal
Biology of the Cell
Author(s)
van Suylekom D., van Donselaar E., Blanchetot C., Do Ngoc L.N., Humbel B.M., Boonstra J.
ISSN
0248-4900 (Print)
ISSN-L
0248-4900
Publication state
Published
Issued date
2007
Volume
99
Number
1
Pages
13-23
Language
english
Abstract
BACKGROUND INFORMATION: Hxt5p is a member of a multigene family of hexose transporter proteins which translocate glucose across the plasma membrane of the yeast Saccharomyces cerevisiae. In contrast with other major hexose transporters of this family, Hxt5p expression is regulated by the growth rate of the cells and not by the external glucose concentration. Furthermore, Hxt5p is the only glucose transporter expressed during stationary phase. These observations suggest a different role for Hxt5p in S. cerevisiae. Therefore we studied the metabolism and localization of Hxt5p in more detail. RESULTS AND CONCLUSIONS: Inhibition of HXT5 expression in stationary-phase cells by the addition of glucose, which increases the growth rate, led to a decrease in the amount of Hxt5 protein within a few hours. Addition of glucose to stationary-phase cells resulted in a transient phosphorylation of Hxt5p on serine residues, but no ubiquitination was detected. The decrease in Hxt5p levels is caused by internalization of the protein, as observed by immunofluorescence microscopy. In stationary-phase cells, Hxt5p was localized predominantly at the cell periphery and upon addition of glucose to the cells the protein translocated to the cell interior. Electron microscopy demonstrated that the internalized Hxt5p-HA (haemagglutinin) protein was localized to small vesicles, multivesicular bodies and the vacuole. These results suggest that internalization and degradation of Hxt5p in the vacuole occur in an ubiquitination-independent manner via the endocytic pathway.
Keywords
Monosaccharide Transport Proteins/metabolism, Monosaccharide Transport Proteins/ultrastructure, Phosphorylation, Protein Processing, Post-Translational, Protein Transport, Recombinant Fusion Proteins/metabolism, Recombinant Fusion Proteins/ultrastructure, Saccharomyces cerevisiae/cytology, Saccharomyces cerevisiae/growth & development, Saccharomyces cerevisiae Proteins/metabolism, Saccharomyces cerevisiae Proteins/ultrastructure, Ubiquitin/metabolism
Pubmed
Web of science
Open Access
Yes
Create date
28/02/2012 18:45
Last modification date
20/08/2019 16:14
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