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 Manlandro, C. M. A.
Right arrow Articles by Rosenwald, A. G.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Manlandro, C. M. A.
Right arrow Articles by Rosenwald, A. G.

 Previous Article  |  Next Article 

Eukaryotic Cell, June 2005, p. 1041-1049, Vol. 4, No. 6
1535-9778/05/$08.00+0     doi:10.1128/EC.4.6.1041-1049.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.

Ability of Sit4p To Promote K+ Efflux via Nha1p Is Modulated by Sap155p and Sap185p

Cara Marie A. Manlandro, Devon H. Haydon,{dagger} and Anne G. Rosenwald*

Department of Biology, Georgetown University, Washington, D.C. 20057

Received 8 November 2004/ Accepted 21 March 2005

We demonstrate here that SAP155 encodes a negative modulator of K+ efflux in the yeast Saccharomyces cerevisiae. Overexpression of SAP155 decreases efflux, whereas deletion increases efflux. In contrast, a homolog of SAP155, called SAP185, encodes a positive modulator of K+ efflux: overexpression of SAP185 increases efflux, whereas deletion decreases efflux. Two other homologs, SAP4 and SAP190, are without effect on K+ homeostasis. Both SAP155 and SAP185 require the presence of SIT4 for function, which encodes a PP2A-like phosphatase important for the G1-S transition through the cell cycle. Overexpression of either the outwardly rectifying K+ channel, Tok1p, or the putative plasma membrane K+/H+ antiporter, Kha1p, increases efflux in both wild-type and sit4{Delta} strains. However, overexpression of the Na+-K+/H+ antiporter, Nha1p, is without effect in a sit4{Delta} strain, suggesting that Sit4p signals to Nha1p. In summary, the combined activities of Sap155p and Sap185p appear to control the function of Nha1p in K+ homeostasis via Sit4p.

* Corresponding author. Mailing address: Department of Biology, Georgetown University, 406 Reiss Science Center, Box 571229, Washington, DC 20057-1229. Phone: (202) 687-5997. Fax: (202) 687-5662. E-mail: rosenwaa{at}georgetown.edu.

{dagger} Present address: University of Florida College of Medicine, Gainesville, Florida.

Eukaryotic Cell, June 2005, p. 1041-1049, Vol. 4, No. 6
1535-9778/05/$08.00+0     doi:10.1128/EC.4.6.1041-1049.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Jablonowski, D., Taubert, J.-E., Bar, C., Stark, M. J. R., Schaffrath, R. (2009). Distinct Subsets of Sit4 Holophosphatases Are Required for Inhibition of Saccharomyces cerevisiae Growth by Rapamycin and Zymocin. Eukaryot Cell 8: 1637-1647 [Abstract] [Full Text]  
  • Lockshon, D., Surface, L. E., Kerr, E. O., Kaeberlein, M., Kennedy, B. K. (2007). The Sensitivity of Yeast Mutants to Oleic Acid Implicates the Peroxisome and Other Processes in Membrane Function. Genetics 175: 77-91 [Abstract] [Full Text]  
  • Stefansson, B., Brautigan, D. L. (2006). Protein Phosphatase 6 Subunit with Conserved Sit4-associated Protein Domain Targets I{kappa}B{epsilon}. J. Biol. Chem. 281: 22624-22634 [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»