This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Wendell, D L Articles by Bisson, L F Search for Related Content PubMed PubMed Citation Articles by Wendell, D L Articles by Bisson, L F

research-article

Physiological characterization of putative high-affinity glucose transport protein Hxt2 of Saccharomyces cerevisiae by use of anti-synthetic peptide antibodies.

Department of Viticulture and Enology, University of California, Davis 95616-8749.

ABSTRACT

Characterization and quantification of the Hxt2 (hexose transport) protein of Saccharomyces cerevisiae indicate that it is one of a set of differentially expressed high-affinity glucose transporters. The protein product of the HXT2 gene was specifically detected by antibodies raised against a synthetic peptide encompassing the 13 carboxyl-terminal amino acids predicted by the HXT2 gene sequence. Hxt2 migrated in sodium dodecyl sulfate-polyacrylamide gel electrophoresis as a broad band or closely spaced doublet with an average M(r) of 47,000. Hxt2 cofractionated with the plasma membrane ATPase, Pma1, indicating that it is a plasma membrane protein. Hxt2 was not solubilized by high pH or urea but was solublized by detergents, which is characteristic of an integral membrane protein. Expression of the Hxt2 protein was measured under two different conditions that produce expression of high-affinity glucose transport: a medium shift from a high (2.0%) to a low (0.05%) glucose concentration (referred to below as high and low glucose) and growth from high to low glucose. Hxt2 as measured by immunoblotting increased 20-fold upon a shift from high-glucose to low-glucose medium, and the high-affinity glucose transport expressed had a strong HXT2-dependent component. Surprisingly, Hxt2 was not detectable when S. cerevisiae growing in high glucose approached glucose exhaustion, and the high-affinity glucose transport expressed under these conditions did not have an HXT2-dependent component. The role of Hxt2 in growth during aerobic batch culture in low-glucose medium was examined. An hxt2 null mutant grew and consumed glucose significantly more slowly than the wild type, and this phenotype correlated directly with appearance of the Hxt2 protein.

This article has been cited by other articles:

• Jansen, M. L. A., De Winde, J. H., Pronk, J. T. (2002). Hxt-Carrier-Mediated Glucose Efflux upon Exposure of Saccharomyces cerevisiae to Excess Maltose. Appl. Environ. Microbiol. 68: 4259-4265 [Abstract] [Full Text]  
• Ozcan, S., Johnston, M. (1999). Function and Regulation of Yeast Hexose Transporters. Microbiol. Mol. Biol. Rev. 63: 554-569 [Abstract] [Full Text]  
• Diderich, J. A., Schepper, M., van Hoek, P., Luttik, M. A. H., van Dijken, J. P., Pronk, J. T., Klaassen, P., Boelens, H. F. M., de Mattos, M. J. T., van Dam, K., Kruckeberg, A. L. (1999). Glucose Uptake Kinetics and Transcription of HXT Genes in Chemostat Cultures of Saccharomyces cerevisiae. J. Biol. Chem. 274: 15350-15359 [Abstract] [Full Text]  
• Meijer, M. M. C., Boonstra, J., Verkleij, A. J., Verrips, C. T. (1998). Glucose Repression in Saccharomyces cerevisiae Is Related to the Glucose Concentration Rather Than the Glucose Flux. J. Biol. Chem. 273: 24102-24107 [Abstract] [Full Text]