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

 Previous Article  |  Next Article 

Mol Cell Biol, February 1998, p. 926-935, Vol. 18, No. 2
0270-7306/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.

Trinucleotide Insertions, Deletions, and Point Mutations in Glucose Transporters Confer K+ Uptake in Saccharomyces cerevisiae

Hong Liang, Christopher H. Ko, Todd Herman, and Richard F. Gaber*

Department of Biochemistry, Molecular Biology and Cell Biology, Northwestern University, Evanston, Illinois 60208

Received 16 July 1997/Returned for modification 23 October 1997/Accepted 24 November 1997

Deletion of TRK1 and TRK2 abolishes high-affinity K+ uptake in Saccharomyces cerevisiae, resulting in the inability to grow on typical synthetic growth medium unless it is supplemented with very high concentrations of potassium. Selection for spontaneous suppressors that restored growth of trk1Delta trk2Delta cells on K+-limiting medium led to the isolation of cells with unusual gain-of-function mutations in the glucose transporter genes HXT1 and HXT3 and the glucose/galactose transporter gene GAL2. 86Rb uptake assays demonstrated that the suppressor mutations conferred increased uptake of the ion. In addition to K+, the mutant hexose transporters also conferred permeation of other cations, including Na+. Because the selection strategy required such gain of function, mutations that disrupted transporter maturation or localization to the plasma membrane were avoided. Thus, the importance of specific sites in glucose transport could be independently assessed by testing for the ability of the mutant transporter to restore glucose-dependent growth to cells containing null alleles of all of the known functional glucose transporter genes. Twelve sites, most of which are conserved among eukaryotic hexose transporters, were revealed to be essential for glucose transport. Four of these have previously been shown to be essential for glucose transport by animal or plant transporters. Eight represented sites not previously known to be crucial for glucose uptake. Each suppressor mutant harbored a single mutation that altered an amino acid(s) within or immediately adjacent to a putative transmembrane domain of the transporter. Seven of 38 independent suppressor mutations consisted of in-frame insertions or deletions. The nature of the insertions and deletions revealed a striking DNA template dependency: each insertion generated a trinucleotide repeat, and each deletion involved the removal of a repeated nucleotide sequence.

* Corresponding author. Mailing address: Department of Biochemistry, Molecular Biology and Cell Biology, Northwestern University, 2153 Sheridan Rd., Evanston, IL 60208. Phone: (847) 491-5452. Fax: (847) 467-1422. E-mail: r-gaber{at}nwu.edu.




This article has been cited by other articles:

  • Vargas, R. C., Garcia-Salcedo, R., Tenreiro, S., Teixeira, M. C., Fernandes, A. R., Ramos, J., Sa-Correia, I. (2007). Saccharomyces cerevisiae Multidrug Resistance Transporter Qdr2 Is Implicated in Potassium Uptake, Providing a Physiological Advantage to Quinidine-Stressed Cells. Eukaryot Cell 6: 134-142 [Abstract] [Full Text]  
  • Thornton, G., Wilkinson, C. R. M., Toone, W. M., Jones, N. (2005). A novel pathway determining multidrug sensitivity in Schizosaccharomyces pombe. GENES CELLS 10: 941-951 [Abstract] [Full Text]  
  • Gaber, R. F., Ottow, K., Andersen, H. A., Kielland-Brandt, M. C. (2003). Constitutive and Hyperresponsive Signaling by Mutant Forms of Saccharomyces cerevisiae Amino Acid Sensor Ssy1. Eukaryot Cell 2: 922-929 [Abstract] [Full Text]  
  • Wagner, R., Straub, M.-L., Souciet, J.-L., Potier, S., de Montigny, J. (2001). New Plasmid System To Select for Saccharomyces cerevisiae Purine-Cytosine Permease Affinity Mutants. J. Bacteriol. 183: 4386-4388 [Abstract] [Full Text]  
  • Kasahara, T., Kasahara, M. (2000). Three Aromatic Amino Acid Residues Critical for Galactose Transport in Yeast Gal2 Transporter. J. Biol. Chem. 275: 4422-4428 [Abstract] [Full Text]  
  • Mulet, J. M., Leube, M. P., Kron, S. J., Rios, G., Fink, G. R., Serrano, R. (1999). A Novel Mechanism of Ion Homeostasis and Salt Tolerance in Yeast: the Hal4 and Hal5 Protein Kinases Modulate the Trk1-Trk2 Potassium Transporter. Mol. Cell. Biol. 19: 3328-3337 [Abstract] [Full Text]  
  • Kasahara, M., Maeda, M. (1998). Contribution to Substrate Recognition of Two Aromatic Amino Acid Residues in Putative Transmembrane Segment 10 of the Yeast Sugar Transporters Gal2 and Hxt2. J. Biol. Chem. 273: 29106-29112 [Abstract] [Full Text]  
  • Ganster, R. W., McCartney, R. R., Schmidt, M. C. (1998). Identification of a Calcineurin-Independent Pathway Required for Sodium Ion Stress Response in Saccharomyces cerevisiae. Genetics 150: 31-42 [Abstract] [Full Text]  
  • Madrid, R., Gomez, M. J., Ramos, J., Rodriguez-Navarro, A. (1998). Ectopic Potassium Uptake in trk1 trk2 Mutants of Saccharomyces cerevisiae Correlates with a Highly Hyperpolarized Membrane Potential. J. Biol. Chem. 273: 14838-14844 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»