IAI FigSearch
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 Gaur, N. K.
Right arrow Articles by Henderson, R. L.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Gaur, N. K.
Right arrow Articles by Henderson, R. L.

 Previous Article  |  Next Article 

Infection and Immunity, November 1999, p. 6040-6047, Vol. 67, No. 11
0019-9567/99/$04.00+0

Overexpression of the Candida albicans ALA1 Gene in Saccharomyces cerevisiae Results in Aggregation following Attachment of Yeast Cells to Extracellular Matrix Proteins, Adherence Properties Similar to Those of Candida albicans

Nand K. Gaur,1,2 Stephen A. Klotz,1,2,3,4,* and Ramona L. Henderson1

Research1 and Specialty Medicine,3 Veterans Affairs Medical Center, Kansas City, Missouri 64128, and Departments of Medicine4 and Microbiology and Immunology,2 University of Kansas School of Medicine, Kansas City, Kansas 66160

Received 13 May 1999/Returned for modification 19 June 1999/Accepted 13 July 1999

Candida albicans maintains a commensal relationship with human hosts, probably by adhering to mucosal tissue in a variety of physiological conditions. We show that adherence due to the C. albicans gene ALA1 when transformed into Saccharomyces cerevisiae, is comprised of two sequential steps. Initially, C. albicans rapidly attaches to extracellular matrix (ECM) protein-coated magnetic beads in small numbers (the attachment phase). This is followed by a relatively slower step in which cell-to-cell interactions predominate (the aggregation phase). Neither of these phases is observed in S. cerevisiae. However, expression of the C. albicans ALA1 gene from a low-copy vector causes S. cerevisiae transformants to attach to ECM-coated magnetic beads without appreciable aggregation. Expression of ALA1 from a high-copy vector results in both attachment and aggregation. Moreover, transcriptional fusion of ALA1 with the galactose-inducible promoters GALS, GALL, and GAL1, allowing for low, moderate, and high levels of inducible transcription, respectively, causes attachment and aggregation that correlates with the strength of the GAL promoter. The adherence of C. albicans and S. cerevisiae overexpressing ALA1 to a number of protein ligands occurs over a broad pH range, is resistant to shear forces generated by vortexing, and is unaffected by the presence of sugars, high salt levels, free ligands, or detergents. Adherence is, however, inhibited by agents that disrupt hydrogen bonds. The similarities in the adherence and aggregation properties of C. albicans and S. cerevisiae overexpressing ALA1 suggest a role in adherence and aggregation for ALA1 and ALA1-like genes in C. albicans.

* Corresponding author. Mailing address: Veterans Affairs Medical Center, 4801 Linwood Blvd., Kansas City, MO 64128. Phone: (816) 861-4700. Fax: (816) 861-1110. E-mail: nkgaur{at}kuhub.cc.ukans.edu.

Infection and Immunity, November 1999, p. 6040-6047, Vol. 67, No. 11
0019-9567/99/$04.00+0


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 © 1999 by the American Society for Microbiology. All rights reserved.