MCB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
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 El Barkani, A.
Right arrow Articles by Mühlschlegel, F. A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by El Barkani, A.
Right arrow Articles by Mühlschlegel, F. A.

 Previous Article  |  Next Article 

Molecular and Cellular Biology, July 2000, p. 4635-4647, Vol. 20, No. 13
0270-7306/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.

Dominant Active Alleles of RIM101 (PRR2) Bypass the pH Restriction on Filamentation of Candida albicans

Abdelmalic El Barkani,1 Oliver Kurzai,1 William A. Fonzi,2 Ana Ramon,2 Amalia Porta,2,3 Matthias Frosch,1 and Fritz A. Mühlschlegel1,*

Institut für Hygiene und Mikrobiologie, Universität Würzburg, 97080 Würzburg, Germany1; Department of Microbiology and Immunology, School of Medicine, Georgetown University Medical Center, Washington, D.C. 20007-21972; and International Institute of Genetics and Biophysics, 80125 Naples, Italy3

Received 29 November 1999/Returned for modification 13 January 2000/Accepted 11 April 2000

Morphological development of the fungal pathogen Candida albicans is profoundly affected by ambient pH. Acidic pH restricts growth to the yeast form, whereas neutral pH permits development of the filamentous form. Superimposed on the pH restriction is a temperature requirement of approximately 37°C for filamentation. The role of pH in development was investigated by selecting revertants of phr2Delta mutants that had gained the ability to grow at acid pH. The extragenic suppressors in two independent revertants were identified as nonsense mutations in the pH response regulator RIM101 (PRR2) that resulted in a carboxy-terminal truncation of the open reading frame. These dominant active alleles conferred the ability to filament at acidic pH, to express PHR1, an alkaline-expressed gene, at acidic pH, and to repress the acid-expressed gene PHR2. It was also observed that both the wild-type and mutant alleles could act as multicopy suppressors of the temperature restriction on filamentation, allowing extensive filamentation at 29°C. The ability of the activated alleles to promote filamentation was dependent upon the developmental regulator EFG1. The results suggest that RIM101 is responsible for the pH dependence of hyphal development.


* Corresponding author. Mailing address: Institut für Hygiene und Mikrobiologie, Universität Würzburg, Josef-Schneider-Strasse 2, 97080 Würzburg, Germany. Phone: 49-931-201-3901. Fax: 49-931-201-3445. E-mail: fmuehlschlegel{at}hygiene.uni-wuerzburg.de.


Molecular and Cellular Biology, July 2000, p. 4635-4647, Vol. 20, No. 13
0270-7306/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.



This article has been cited by other articles:




Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. J. Virol. Eukaryot. Cell
Microbiol. Mol. Biol. Rev. Clin. Vaccine Immunol. All ASM Journals

Copyright © 2000 by the American Society for Microbiology. All rights reserved.