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 Mao, Y.
Right arrow Articles by Wong, B.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Mao, Y.
Right arrow Articles by Wong, B.

 Previous Article  |  Next Article 

Journal of Bacteriology, December 1999, p. 7235-7242, Vol. 181, No. 23
0021-9193/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.

Overexpression of a Dominant-Negative Allele of SEC4 Inhibits Growth and Protein Secretion in Candida albicans

Yuxin Mao,1 Vernon F. Kalb,1 and Brian Wong2,*

Infectious Diseases Section, Department of Internal Medicine, Yale University School of Medicine, New Haven,1 and Infectious Diseases Section, VA Connecticut Healthcare System, West Haven,2 Connecticut

Received 5 April 1999/Accepted 15 September 1999

Candida albicans SEC4 was cloned by complementing the Saccharomyces cerevisiae sec4-8 mutation, and its deduced protein product (Sec4p) was 63% identical to S. cerevisiae Sec4p. One chromosomal SEC4 allele in C. albicans CAI4 was readily disrupted by homologous gene targeting, but efforts to disrupt the second allele yielded no viable null mutants. Although this suggested that C. albicans SEC4 was essential, it provided no information about this gene's functions. Therefore, we constructed a mutant sec4 allele encoding an amino acid substitution (Ser-28right-arrowAsn) analogous to the Ser-17right-arrowAsn substitution in a trans-dominant inhibitor of mammalian Ras protein. GAL1-regulated expression plasmids carrying the mutant sec4 allele (pS28N) had minimal effects in glucose-incubated C. albicans transformants, but six of nine transformants tested grew very slowly in galactose. Incubation of pS28N transformants in galactose also inhibited secretion of aspartyl protease (Sap) and caused 90-nm secretory vesicles to accumulate intracellularly, and plasmid curing restored growth and Sap secretion to wild-type levels. These results imply that C. albicans SEC4 is required for growth and protein secretion and that it functions at a later step in the protein secretion pathway than formation of post-Golgi secretory vesicles. They also demonstrate the feasibility of using inducible dominant-negative alleles to define the functions of essential genes in C. albicans.

* Corresponding author. Mailing address: Infectious Diseases Section, VA Connecticut Healthcare System, 950 Campbell Ave. (111-I), West Haven, CT 06516. Phone: (203) 937-3446. Fax: (203) 937-3476. E-mail: brian.wong{at}yale.edu.

Journal of Bacteriology, December 1999, p. 7235-7242, Vol. 181, No. 23
0021-9193/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:

  • Yoneda, A., Doering, T. L. (2006). A Eukaryotic Capsular Polysaccharide Is Synthesized Intracellularly and Secreted via Exocytosis. Mol. Biol. Cell 17: 5131-5140 [Abstract] [Full Text]  
  • Siriputthaiwan, P., Jauneau, A., Herbert, C., Garcin, D., Dumas, B. (2005). Functional analysis of CLPT1, a Rab/GTPase required for protein secretion and pathogenesis in the plant fungal pathogen Colletotrichum lindemuthianum. J. Cell Sci. 118: 323-329 [Abstract] [Full Text]  
  • Lee, S. A., Mao, Y., Zhang, Z., Wong, B. (2001). Overexpression of a dominant-negative allele of YPT1 inhibits growth and aspartyl protease secretion in Candida albicans. Microbiology 147: 1961-1970 [Abstract] [Full Text]  
  • Weber, Y., Santore, U. J., Ernst, J. F., Swoboda, R. K. (2001). Divergence of Eukaryotic Secretory Components: the Candida albicans Homolog of the Saccharomyces cerevisiae Sec20 Protein Is N Terminally Truncated, and Its Levels Determine Antifungal Drug Resistance and Growth. J. Bacteriol. 183: 46-54 [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»