The two-component histidine kinase Chk1p of has been implicated in the regulation of cell wall biosynthesis. Deletion of results in avirulence that in part may be due to the increased sensitivity of mutant strains to polymorphonuclear leukocytes. The mutant also does not adhere to human oesophageal tissue , probably as a consequence of its altered cell wall. In the current study, a promoter- reporter () construct was expressed in wild-type strain CAI4 and in two-component signal transduction mutants to determine the effect of environmental stress conditions on the regulation of and the co-regulatory activities among these proteins. It is shown that expression varied according to the type of growth conditions and incubation time; expression was also influenced by the strain background. expression in CAI4 was greater at 37 °C and at a pH of 3·5 and in the presence of 4 mM HO, 0·1 mM menadione, 10 % serum or 1·5 M NaCl compared to cells grown at 30 or 42 °C. The increases in expression were time-dependent and not observed until cells were incubated for 120 min in these conditions (<0·05). As a correlate of the increase in transcription of - in the presence of HO, the mutant was more sensitive than wild-type and revertant cells to HO . In addition to strain CAI4, we also measured - reporter activity of mutants deleted in genes encoding other two-component proteins such as the response regulator gene , the histidine kinases, and , and the MAP kinase. Of these proteins, Ssk1p and Sln1p are presumed to mediate phosphotransfer to the HOG1 [ypersmotic lycerol] MAP kinase pathway during oxidative and perhaps osmotic stress in . Compared to strain CAI4, reporter activity increased significantly in the mutant under all growth conditions after a 10 and 120 min incubation (<0·0001). expression in the mutant was less at 42 °C compared to all other growth conditions (<0·05). Furthermore, reporter activity also increased in the mutant of . These data suggest that and indirectly or directly negatively regulate under most growth conditions tested. In the mutant, downregulation of was observed in all growth conditions compared to strain CAI4 (<0·05), while regulation of in the mutant was similar to strain CAI4 except when cells were incubated in the presence of 4 mM HO for 120 min (<0·05). Western blot analysis was used to determine the role of Chk1p in phosphorylation of Hog1p under oxidative or osmotic stress. It was found that Hog1p was phosphorylated in the mutant similar to wild-type CAF2-1 cells, although the temporal events of phosphorylation differed slightly in mutant cells. These results show that transcription of , as measured by the reporter assay, is statistically increased when cells are exposed to several types of stress or when incubated in 10 % serum in a mutant-specific background and at a specific time point. Of importance, our data also suggest that expression is indirectly or directly regulated by the HOG1 MAP kinase pathway, although a determination of its position in this pathway or in a cross-talking pathway awaits additional studies.


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  1. Alex, L. A., Korch, C., Selitrennikoff, C. P. & Simon, M. I.(1998).COS1, a two-component histidine kinase that is involved in hyphal development in the opportunistic pathogen, Candida albicans. Proc Natl Acad Sci U S A 95, 7069–7073.[CrossRef] [Google Scholar]
  2. Alonso-Monge, R., Navarro-García, F., Molero, G., Diez-Orejas, R., Gustin, M., Pla, J., Sanchez, M. & Nombela, C.(1999). Role of mitogen-activated protein kinase Hog1p in morphogenesis and virulence of Candida albicans. J Bacteriol 181, 3058–3068. [Google Scholar]
  3. Alonso-Monge, R., Navarro-García, F., Roman, E., Negredo, A., Eisman, B., Nombela, C. & Pla, J.(2003). The Hog1 MAP kinase is essential in the oxidative stress response and chlamydospore formation in Candida albicans. Eukaryot Cell 2, 351–361.[CrossRef] [Google Scholar]
  4. Barrett, J. F. & Hoch, J.(1998). Two-component signal transduction as a target for microbial anti-infective therapy. Antimicrob Agents Chemother 42, 1529–1536. [Google Scholar]
  5. Berman, J. & Sudbery, P. E.(2002).Candida albicans: a molecular revolution built on lessons from budding yeast. Nature Rev 3, 918–930. [Google Scholar]
  6. Bernhardt, J., Herman, D., Sheridan, M. & Calderone, R. A.(2001). Adherence and invasion studies of Candida albicans strains utilizing in vitro models of esophageal candidiasis. J Infect Dis 184, 1170–1175.[CrossRef] [Google Scholar]
  7. Bodey, G. P., Buckley, M., Sathe, Y. S. & Freirch, E. J.(1966). Quantitative relationship between circulating leukocytes and infections in patients with acute leukemia. Ann Intern Med 64, 328–340.[CrossRef] [Google Scholar]
  8. Buck, V., Quinn, J., Pine, T., Martin, H., Saldanka, J., Makino, K., Morgan, B. & Millar, J. B. A.(2001). Peroxide sensors for the fission yeast stress activated mitogen-activated kinase pathway. Mol Cell Biol 12, 407–419.[CrossRef] [Google Scholar]
  9. Calderone, R. A. & Fonzi, W. A.(2001). Virulence factors of Candida albicans. Trends Microbiol 9, 327–335.[CrossRef] [Google Scholar]
  10. Calera, J. A. & Calderone, R. A.(1999a). Flocculation of hyphae is associated with a deletion in the putative CaHK1 two-component histidine kinase gene from Candida albicans. Microbiology 145, 1431–1442.[CrossRef] [Google Scholar]
  11. Calera, J. A. & Calderone, R. A.(1999b). Histidine kinase, two-component signal transduction proteins of Candida albicans and the pathogenesis of candidosis. Mycoses 42, 49–53. [Google Scholar]
  12. Calera, J. A., Cho, G. & Calderone, R. A.(1998). Identification of a putative histidine kinase two-component phosphorelay gene (CaCHK1) in Candida albicans. Yeast 14, 665–674.[CrossRef] [Google Scholar]
  13. Calera, J. A., Zhao, X.-J., Sheridan, M. & Calderone, R. A.(1999). Avirulence of Candida albicans CaHK1 mutants in a murine model of hematogenously disseminated candidiasis. Infect Immun 67, 4280–4284. [Google Scholar]
  14. Calera, J. A., Zhao, X.-J. & Calderone, R. A.(2000a). Defective hyphal formation and avirulence caused by a deletion of the CSSK1 response regulator gene in Candida albicans. Infect Immun 68, 518–525.[CrossRef] [Google Scholar]
  15. Calera, J. A., Herman, D. & Calderone, R. A.(2000b). Identification of YPD1, a gene of Candida albicans which encodes a two-component phospho-histidine intermediate protein. Yeast 16, 1053–1059.[CrossRef] [Google Scholar]
  16. Chauhan, N., Inglis, D., Roman, E., Pla, J., Li, D., Calera, J. & Calderone, R. A.(2003).Candida albicans response regulator gene SSK1 regulates a subset of genes whose functions are associated with cell wall biosynthesis and adaptation to oxidative stress. Eukaryot Cell 2, 1018–1024.[CrossRef] [Google Scholar]
  17. Fonzi, W. A. & Irwin, M. Y.(1993). Isogenic strain construction and gene mapping in Candida albicans. Genetics 134, 717–728. [Google Scholar]
  18. Hohmann, S.(2002). Osmotic stress signaling and osmoadaptation in yeasts. Microbiol Mol Biol Rev 66, 300–372.[CrossRef] [Google Scholar]
  19. Kapteyn, J. C., Hoyer, L. L., Hecht, J. E., Muller, W. H., Andel, A., Verkleij, A. J., Makarow, M., Van den Ende, H. & Klis, F. M.(2000). The cell wall architecture of Candida albicans wild-type cells and cell wall-deficient mutants. Mol Microbiol 35, 601–611. [Google Scholar]
  20. Koretke, K. K., Lupas, A. N., Warren, P. V., Rosenberg, M. & Brown, J. R.(2000). Evolution of two-component signal transduction. Mol Biol Evol 17, 1956–1970.[CrossRef] [Google Scholar]
  21. Kruppa, M., Goins, T., Cutler, J. E. & 7 other authors(2003). The role of the Candida albicans histidine kinase (CHK1) gene in the regulation of cell wall mannan and glucan biosynthesis. FEMS Yeast Res 3, 289–299. [Google Scholar]
  22. Kruppa, M., Krom, B., Chauhan, N., Bambach, A., Cihlar, R. & Calderone, R.(2004a). The two-component signal transduction protein, Chk1p, regulates quorum sensing in Candida albicans. Eukaryot Cell 3, 1062–1065.[CrossRef] [Google Scholar]
  23. Kruppa, M., Jabra-Rizk, M., Meiller, T. F. & Calderone, R. A.(2004b). The histidine kinases of Candida albicans: regulation of cell wall mannan biosynthesis. FEMS Yeast Res 4, 409–416.[CrossRef] [Google Scholar]
  24. Lengler, K. B., Davidson, R. C., D'Souza, C., Harashima, T., Shen, W.-C., Wang, P., Pan, X., Waugh, M. & Heitman, J.(2000). Signal transduction cascades regulating fungal development and virulence. Microbiol Mol Biol Rev 64, 746–785.[CrossRef] [Google Scholar]
  25. Leuker, C. E., Hahn, A. & Ernst, J. F.(1992).β-Galactosidase of Kluyveromyces lactis (Lac4p) as reporter of gene expression in Candida albicans and C. tropicalis. Mol Gen Genet 235, 235–241.[CrossRef] [Google Scholar]
  26. Li, D., Bernhardt, J. & Calderone, R.(2002). Temporal expression of the Candida albicans genes CHK1 and CSSK1, adherence and morphogenesis in a model of reconstituted human esophageal epithelial candidiasis. Infect Immun 70, 1558–1565.[CrossRef] [Google Scholar]
  27. Nagahashi, S., Mio, T., Ono, N., Yamada-Okabe, T., Arisawa, M., Bussey, H. & Yamada-Okabe, H.(1998). Isolation of CaSLN1 and CaNIK1, the genes for osmosensing histidine kinase homologues, from the pathogenic fungus Candida albicans. Microbiology 144, 425–432.[CrossRef] [Google Scholar]
  28. 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]
  29. Pott, G. B., Miller, T. K., Bartlett, J. A., Palas, J. S. & Selitrennikoff, C. P.(2000). The isolation of FOS-1, a gene encoding a putative two-component histidine kinase from Aspergillus fumigatus. Fungal Genet Biol 31, 55–67.[CrossRef] [Google Scholar]
  30. Santos, J. L. & Shiozaki, K.(2001). Fungal histidine kinases. Sci Stke 98, RE1. [Google Scholar]
  31. Selitrennikoff, C. P., Alex, L., Miller, T. K., Clemons, K., Simon, M. I. & Stevens, D. A.(2001).COS-1, a putative two-component histidine kinase of Candida albicans, is an in vivo virulence factor. Med Mycol 39, 69–75.[CrossRef] [Google Scholar]
  32. Singh, P., Chauhan, N., Ghosh, A., Dixon, F. & Calderone, R.(2004). The SKN7 of Candida albicans: mutant construction and phenotype analysis. Infect Immun 72, 2390–2394.[CrossRef] [Google Scholar]
  33. Srikantha, T.(1996). The sea pansy Renilla reniformis luciferase serves as a sensitive bioluminescent reporter for differential gene expression in Candida albicans. J Bacteriol 178, 121–129. [Google Scholar]
  34. Srikantha, T., Tsai, L., Daniels, K., Enger, L., Highley, K. & Soll, D. R.(1998). The two-component hybrid kinase regulator CaNIK1 of Candida albicans. Microbiology 144, 2715–2729.[CrossRef] [Google Scholar]
  35. Torosantucci, A., Chiani, P., DeBernardis, F., Cassone, A., Calera, J. A. & Calderone, R. A.(2002). Deletion of the two-component histidine kinase gene (CHK1) of Candida albicans contributes to enhanced growth inhibition and killing by human neutrophils in vitro. Infect Immun 70, 985–987.[CrossRef] [Google Scholar]
  36. Uhl, M. A. & Johnson, A. D.(2001). Development of Streptococcus thermophilus lacZ as a reporter gene for Candida albicans. Microbiology 147, 1189–1195. [Google Scholar]
  37. Wenzel, R. P.(1995). Nosocomial candidiasis: risk factors and attributable mortality. Clin Infect Dis 20, 1531–1534.[CrossRef] [Google Scholar]
  38. Yamada-Okabe, T., Mio, T., Ono, N., Kashima, Y., Matsui, M., Arisawa, M. & Yamada-Okabe, H.(1999). Roles of three histidine kinase genes in hyphal development and virulence of the pathogenic fungus, Candida albicans. J Bacteriol 181, 7243–7247. [Google Scholar]

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vol. , part 10, pp. 3305-3313

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