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 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 Wang, Z.
Right arrow Articles by Szaniszlo, P. J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Wang, Z.
Right arrow Articles by Szaniszlo, P. J.

Infection and Immunity, December 1999, p. 6619-6630, Vol. 67, No. 12
0019-9567/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.

WdChs4p, a Homolog of Chitin Synthase 3 in Saccharomyces cerevisiae, Alone Cannot Support Growth of Wangiella (Exophiala) dermatitidis at the Temperature of Infection

Zheng Wang,1 Li Zheng,1 Melinda Hauser,2 Jeffery M. Becker,2 and Paul J. Szaniszlo1,*

Section of Molecular Genetics and Microbiology, School of Biological Science and Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas 78712,1 and Microbiology Department, University of Tennessee, Knoxville, Tennessee 379192

Received 21 April 1999/Returned for modification 14 June 1999/Accepted 3 September 1999

By using improved transformation methods for Wangiella dermatitidis, and a cloned fragment of its chitin synthase 4 structural gene (WdCHS4) as a marking sequence, the full-length gene was rescued from the genome of this human pathogenic fungus. The encoded chitin synthase product (WdChs4p) showed high homology with Chs3p of Saccharomyces cerevisiae and other class IV chitin synthases, and Northern blotting showed that WdCHS4 was expressed at constitutive levels under all conditions tested. Reduced chitin content, abnormal yeast clumpiness and budding kinetics, and increased melanin secretion resulted from the disruption of WdCHS4 suggesting that WdChs4p influences cell wall structure, cellular reproduction, and melanin deposition, respectively. However, no significant loss of virulence was detected when the wdchs4Delta strain was tested in an acute mouse model. Using a wdchs1Delta wdchs2Delta wdchs3Delta triple mutant of W. dermatitidis, which grew poorly but adequately at 25°C, we assayed WdChs4p activity in the absence of activities contributed by its three other WdChs proteins. Maximal activity required trypsin activation, suggesting a zymogenic nature. The activity also had a pH optimum of 7.5, was most stimulated by Mg2+, and was more inhibited by polyoxin D than by nikkomycin Z. Although the WdChs4p activity had a broad temperature optimum between 30 to 45°C in vitro, this activity alone did not support the growth of the wdchs1Delta wdchs2Delta wdchs3Delta triple mutant at 37°C, a temperature commensurate with infection.

* Corresponding author. Mailing address: Section of Molecular Genetics and Microbiology, School of Biological Sciences, University of Texas at Austin, Austin, TX 78712. Phone: (512) 471-3384. Fax: (512) 471-7088. E-mail: pjszaniszlo{at}mail.utexas.edu.

Infection and Immunity, December 1999, p. 6619-6630, Vol. 67, No. 12
0019-9567/99/$04.00+0
Copyright © 1999, 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 © 1999 by the American Society for Microbiology. All rights reserved.