1887

Abstract

Chitin is a structural polysaccharide present in most fungal cell walls, whose synthesis depends on a family of enzymic activities named chitin synthases (CSs). The specific role of each of them, as well as of their regulatory proteins, in cell morphogenesis and virulence is not well understood. Here, it is shown that most chitin synthesis in , one of the fungi most commonly isolated from opportunistic mycoses and infections, depends on . Thus, Δ null mutants showed reduced levels of chitin and CS activity, and were resistant to Calcofluor. Despite the sequence similarity and functional relationship with ScChs7p, CaChs7p was unable to restore CSIII activity in a Δ null mutant, because it was unable to direct ScChs3p export from the endoplasmic reticulum. Δ null mutants did not show any defect in growth rate, but yeast cells displayed minor morphogenetic defects affecting septum formation, and showed an increased tendency to form filaments. CaChs7p was not required for germ-tube emission, and null mutant strains underwent the dimorphic transition correctly. However, colony morphology appeared distinctively affected. Δ hyphae were very curved and had irregular lateral walls, resulting in very compact colonies that seemed unable to spread out radially on the surface, unlike the wild-type. This growth pattern may be associated with the reduced virulence and high clearance rate observed when the Δ strain was used in a murine model of infection. Therefore, CaChs7p is required for normal hyphal morphogenesis, suggesting that in CSIII plays an important role in maintaining cell wall integrity, being essential when invading surrounding tissues.

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2005-08-01
2019-10-20
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References

  1. Brand, A., MacCallum, D. M., Brown, A. J., Gow, N. A. & Odds, F. C. ( 2004; ). Ectopic expression of URA3 can influence the virulence phenotypes and proteome of Candida albicans but can be overcome by targeted reintegration of URA3 at the RPS10 locus. Eukaryot Cell 3, 900–909.[CrossRef]
    [Google Scholar]
  2. Braun, P. C. & Calderone, R. A. ( 1978; ). Chitin synthesis in Candida albicans: comparison of yeast and hyphal forms. J Bacteriol 133, 1472–1477.
    [Google Scholar]
  3. Brown, A. J. & Gow, N. A. ( 1999; ). Regulatory networks controlling Candida albicans morphogenesis. Trends Microbiol 7, 333–338.[CrossRef]
    [Google Scholar]
  4. Bulawa, C. E., Miller, D. W., Henry, L. K. & Becker, J. M. ( 1995; ). Attenuated virulence of chitin-deficient mutants of Candida albicans. Proc Natl Acad Sci U S A 92, 10570–10574.[CrossRef]
    [Google Scholar]
  5. Calderone, R. A. & Fonzi, W. A. ( 2001; ). Virulence factors of Candida albicans. Trends Microbiol 9, 327–335.[CrossRef]
    [Google Scholar]
  6. Cassone, A. ( 1986; ). Cell wall of pathogenic yeasts and implications for antimycotic therapy. Drugs Exp Clin Res 12, 635–643.
    [Google Scholar]
  7. Chaffin, W. L., Lopez-Ribot, J. L., Casanova, M., Gozalbo, D. & Martinez, J. P. ( 1998; ). Cell wall and secreted proteins of Candida albicans: identification, function, and expression. Microbiol Mol Biol Rev 62, 130–180.
    [Google Scholar]
  8. Choi, W. J. ( 1998; ). The determination of chitin synthases by varying pH and divalent cations in Candida albicans. J Microbiol Biotechnol 8, 613–617.
    [Google Scholar]
  9. Choi, W. & Cabib, E. ( 1994; ). The use of divalent cations and pH for the determination of specific yeast chitin synthases. Anal Biochem 219, 368–372.[CrossRef]
    [Google Scholar]
  10. Finney, D. J. ( 1964; ). The Spearman-Kärber method. In Statistical Methods Biological Assay, pp. 524–530. Edited by D. J. Finney. London: Charles Griffin.
  11. Fonzi, W. A. & Irwin, M. Y. ( 1993; ). Isogenic strain construction and gene mapping in Candida albicans. Genetics 134, 717–728.
    [Google Scholar]
  12. Gaughran, J. P., Lai, M. H., Kirsch, D. P. & Silverman, S. J. ( 1994; ). Nikkomycin Z is a specific inhibitor of Saccharomyces cerevisiae chitin synthase isozyme Chs3 in vitro and in vivo. J Bacteriol 176, 5857–5860.
    [Google Scholar]
  13. Gillum, A. M., Tsay, E. Y. & Kirsch, D. R. ( 1984; ). Isolation of the Candida albicans gene for orotidine-5′-phosphate decarboxylase by complementation of S. cerevisiae ura3 and E. coli pyrF mutations. Mol Gen Genet 198, 179–182.[CrossRef]
    [Google Scholar]
  14. Gow, N. A. & Gooday, G. W. ( 1982; ). Growth kinetics and morphology of colonies of the filamentous form of Candida albicans. J Gen Microbiol 128, 2187–2194.
    [Google Scholar]
  15. Gow, N. A. R., Robbins, P. W., Lester, J. W., Brown, A. J. P., Fonzi, W. A., Chapman, T. & Kinsman, O. S. ( 1994; ). A hyphal-specific chitin synthase gene (CHS2) is not essential for growth, dimorphism, or virulence of Candida albicans. Proc Natl Acad Sci U S A 91, 6216–6220.[CrossRef]
    [Google Scholar]
  16. Kim, M. K., Park, H. S., Kim, C. H., Park, H. M. & Choi, W. ( 2002; ). Inhibitory effect of nikkomycin Z on chitin synthases in Candida albicans. Yeast 19, 341–349.[CrossRef]
    [Google Scholar]
  17. Klis, F. M., De Groot, P. & Hellingwerf, K. ( 2001; ). Molecular organization of the cell wall of Candida albicans. Med Mycol 39, 1–8.[CrossRef]
    [Google Scholar]
  18. Lee, K. L., Buckley, H. R. & Campbell, C. C. ( 1975; ). An amino acid liquid synthetic medium for the development of mycelial and yeast forms of Candida albicans. Sabouraudia 13, 148–153.[CrossRef]
    [Google Scholar]
  19. Liu, H., Kohler, J. & Fink, G. R. ( 1994; ). Suppression of hyphal formation in Candida albicans by mutation of a STE12 homolog. Science 266, 1723–1726.[CrossRef]
    [Google Scholar]
  20. Mattia, E., Carruba, G., Angiolella, L. & Cassone, A. ( 1982; ). Induction of germ tube formation by N-acetyl-d-glucosamine in Candida albicans: uptake of inducer and germinative response. J Bacteriol 152, 555–562.
    [Google Scholar]
  21. Mio, T., Yabe, T., Sudoh, M., Satoh, Y., Nakajima, T., Arisawa, M. & Yamada-Okabe, H. ( 1996; ). Role of three chitin synthase genes in the growth of Candida albicans. J Bacteriol 178, 2416–2419.
    [Google Scholar]
  22. Mumberg, D., Muller, R. & Funk, M. ( 1994; ). Regulatable promoters of Saccharomyces cerevisiae: comparison of transcriptional activity and their use for heterologous expression. Nucleic Acids Res 22, 5767–5768.[CrossRef]
    [Google Scholar]
  23. Munro, C. A. & Gow, N. A. R. ( 2001; ). Chitin synthesis in human pathogenic fungi. Med Mycol 39, 41–53.[CrossRef]
    [Google Scholar]
  24. Munro, C. A., Schofield, D. A., Gooday, G. W. & Gow, N. A. ( 1998; ). Regulation of chitin synthesis during dimorphic growth of Candida albicans. Microbiology 144, 391–401.[CrossRef]
    [Google Scholar]
  25. Munro, C. A. K. W., Buchan, A., Henry, K., Becker, J. M., Brown, A. J., Bulawa, C. E. & Gow, N. A. R. ( 2001; ). Chs1 of Candida albicans is an essential chitin synthase required for synthesis at the septum and for cell integrity. Mol Microbiol 39, 1414–1426.
    [Google Scholar]
  26. Munro, C. A., Whitton, R. K., Hughes, H. B., Rella, M., Selvaggini, S. & Gow, N. A. ( 2003; ). CHS8 a fourth chitin synthase gene of Candida albicans contributes to in vitro chitin synthase activity, but is dispensable for growth. Fungal Genet Biol 40, 146–158.[CrossRef]
    [Google Scholar]
  27. Murad, A. M., Lee, P. R., Broadbent, I. D., Barelle, C. J. & Brown, A. J. ( 2000; ). CIp10, an efficient and convenient integrating vector for Candida albicans. Yeast 16, 325–327.[CrossRef]
    [Google Scholar]
  28. Navarro-Garcia, F., Sanchez, M., Pla, J. & Nombela, C. ( 1995; ). Functional characterization of the MKC1 gene of Candida albicans, which encodes a mitogen-activated protein kinase homolog related to cell integrity. Mol Cell Biol 15, 2197–2206.
    [Google Scholar]
  29. Navarro-Garcia, F., Sanchez, M., Nombela, C. & Pla, J. ( 2001; ). Virulence genes in the pathogenic yeast Candida albicans. FEMS Microbiol Rev 25, 245–268.[CrossRef]
    [Google Scholar]
  30. Roncero, C. ( 2002; ). The genetic complexity of chitin synthesis in fungi. Curr Genet 41, 367–378.[CrossRef]
    [Google Scholar]
  31. Roncero, C., Valdivieso, M. H., Ribas, J. C. & Durán, A. ( 1988; ). Isolation and characterization of Saccharomyces cerevisiae mutants resistant to Calcofluor white. J Bacteriol 170, 1950–1954.
    [Google Scholar]
  32. Santos, B. & Snyder, M. ( 1997; ). Targeting of chitin synthase 3 to polarized growth sites in yeast requires Chs5p and Myo2p. J Cell Biol 136, 95–110.[CrossRef]
    [Google Scholar]
  33. Sanz, M., Trilla, J. A., Durán, A. & Roncero, C. ( 2002; ). Control of chitin synthesis through Shc1p, a functional homologue of Chs4p specifically induced during sporulation. Mol Microbiol 43, 1183–1195.[CrossRef]
    [Google Scholar]
  34. Smits, G. J., van den Ende, H. & Klis, F. M. ( 2001; ). Differential regulation of cell wall biogenesis during growth and development in yeast. Microbiology 147, 781–784.
    [Google Scholar]
  35. Staib, P., Kretschmar, M., Nichterlein, T., Hof, H. & Morschhauser, J. ( 2002; ). Host versus in vitro signals and intrastrain allelic differences in the expression of a Candida albicans virulence gene. Mol Microbiol 44, 1351–1366.[CrossRef]
    [Google Scholar]
  36. Sudoh, M., Tatsuno, K., Ono, N., Chibana, H., Yamada-Okabe, H. & Arisawa, M. ( 1999; ). The Candida albicans CHS4 gene complements a Saccharomyces cerevisiae skt5/chs4 mutation and is involved in chitin biosynthesis. Microbiology 145, 1613–1622.[CrossRef]
    [Google Scholar]
  37. Thompson, J. R., Register, E., Curotto, J., Kurtz, M. & Kelly, R. ( 1998; ). An improved protocol for the preparation of yeast cells for transformation by electroporation. Yeast 14, 565–571.[CrossRef]
    [Google Scholar]
  38. Trilla, J. A., Durán, A. & Roncero, C. ( 1999; ). Chs7p, a new protein involved in the control of protein export from the endoplasmic reticulum that is specifically engaged in the regulation of chitin synthesis in Saccharomyces cerevisiae. J Cell Biol 145, 1153–1163.[CrossRef]
    [Google Scholar]
  39. Valdivieso, M. H., Durán, A. & Roncero, C. ( 2004; ). Chitin biosynthesis and morphogenetic processes. In The Mycota, vol. III, Biochemistry and Molecular Biology, pp. 275–290. Edited by R. Brambl & G.A. Marzluf. Berlin & Heildelberg: Springer.
  40. Warenda, A. J. & Konopka, J. B. ( 2002; ). Septin function in Candida albicans morphogenesis. Mol Biol Cell 13, 2732–2746.[CrossRef]
    [Google Scholar]
  41. Warenda, A. J., Kauffman, S., Sherrill, T. P., Becker, J. M. & Konopka, J. B. ( 2003; ). Candida albicans septin mutants are defective for invasive growth and virulence. Infect Immun 71, 4045–4051.[CrossRef]
    [Google Scholar]
  42. Zaragoza, O., de Virgilio, C., Ponton, J. & Gancedo, C. ( 2002; ). Disruption in Candida albicans of the TPS2 gene encoding trehalose-6-phosphate phosphatase affects cell integrity and decreases infectivity. Microbiology 148, 1281–1290.
    [Google Scholar]
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