Abstract
Histoplasma capsulatum is a pathogenic fungus with two distinct morphologies and lifestyles. The saprophytic form of this organism, a mold, thrives in soil and is especially abundant in the Ohio and Mississippi River valleys. Its parasitic counterpart, a yeast, colonizes phagolysosomes of mammalian macrophages. We have observed a major difference in the calcium requirements of the two forms of Histoplasma, potentially implicating the phagolysosome as a calcium-limiting compartment. Deprivation of calcium by the addition of EGTA to culture media inhibited the growth of mycelial H. capsulatum but had no effect on yeast growth in vitro. In addition, yeasts released a calcium-binding protein (CBP) detectable by a 45CaCl2 blotting technique. CBP was a major component of yeast culture supernatant and was also detectable by ruthenium red staining, another assay for calcium-binding activity. Conversely, mycelial H. capsulatum did not produce CBP, a finding that correlates with the dependence of mycelia on calcium for growth. We also describe here the purification of CBP from yeast culture supernatant by reversed-phase high-pressure liquid chromatography.
Full Text
The Full Text of this article is available as a PDF (678.4 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Burgess W. H., Jemiolo D. K., Kretsinger R. H. Interaction of calcium and calmodulin in the presence of sodium dodecyl sulfate. Biochim Biophys Acta. 1980 Jun 26;623(2):257–270. doi: 10.1016/0005-2795(80)90254-8. [DOI] [PubMed] [Google Scholar]
- Charuk J. H., Pirraglia C. A., Reithmeier R. A. Interaction of ruthenium red with Ca2(+)-binding proteins. Anal Biochem. 1990 Jul;188(1):123–131. doi: 10.1016/0003-2697(90)90539-l. [DOI] [PubMed] [Google Scholar]
- Davis T. N., Urdea M. S., Masiarz F. R., Thorner J. Isolation of the yeast calmodulin gene: calmodulin is an essential protein. Cell. 1986 Nov 7;47(3):423–431. doi: 10.1016/0092-8674(86)90599-4. [DOI] [PubMed] [Google Scholar]
- Eissenberg L. G., Goldman W. E. Histoplasma variation and adaptive strategies for parasitism: new perspectives on histoplasmosis. Clin Microbiol Rev. 1991 Oct;4(4):411–421. doi: 10.1128/cmr.4.4.411. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Eissenberg L. G., Goldman W. E., Schlesinger P. H. Histoplasma capsulatum modulates the acidification of phagolysosomes. J Exp Med. 1993 Jun 1;177(6):1605–1611. doi: 10.1084/jem.177.6.1605. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Eissenberg L. G., Schlesinger P. H., Goldman W. E. Phagosome-lysosome fusion in P388D1 macrophages infected with Histoplasma capsulatum. J Leukoc Biol. 1988 Jun;43(6):483–491. doi: 10.1002/jlb.43.6.483. [DOI] [PubMed] [Google Scholar]
- Eissenberg L. G., West J. L., Woods J. P., Goldman W. E. Infection of P388D1 macrophages and respiratory epithelial cells by Histoplasma capsulatum: selection of avirulent variants and their potential role in persistent histoplasmosis. Infect Immun. 1991 May;59(5):1639–1646. doi: 10.1128/iai.59.5.1639-1646.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- García Véscovi E., Soncini F. C., Groisman E. A. Mg2+ as an extracellular signal: environmental regulation of Salmonella virulence. Cell. 1996 Jan 12;84(1):165–174. doi: 10.1016/s0092-8674(00)81003-x. [DOI] [PubMed] [Google Scholar]
- Klimpel K. R., Goldman W. E. Isolation and characterization of spontaneous avirulent variants of Histoplasma capsulatum. Infect Immun. 1987 Mar;55(3):528–533. doi: 10.1128/iai.55.3.528-533.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Levitz S. M., Diamond R. D. A rapid colorimetric assay of fungal viability with the tetrazolium salt MTT. J Infect Dis. 1985 Nov;152(5):938–945. doi: 10.1093/infdis/152.5.938. [DOI] [PubMed] [Google Scholar]
- Maruyama K., Mikawa T., Ebashi S. Detection of calcium binding proteins by 45Ca autoradiography on nitrocellulose membrane after sodium dodecyl sulfate gel electrophoresis. J Biochem. 1984 Feb;95(2):511–519. doi: 10.1093/oxfordjournals.jbchem.a134633. [DOI] [PubMed] [Google Scholar]
- Oakley B. R., Kirsch D. R., Morris N. R. A simplified ultrasensitive silver stain for detecting proteins in polyacrylamide gels. Anal Biochem. 1980 Jul 1;105(2):361–363. doi: 10.1016/0003-2697(80)90470-4. [DOI] [PubMed] [Google Scholar]
- Pollack C., Straley S. C., Klempner M. S. Probing the phagolysosomal environment of human macrophages with a Ca2+-responsive operon fusion in Yersinia pestis. 1986 Aug 28-Sep 3Nature. 322(6082):834–836. doi: 10.1038/322834a0. [DOI] [PubMed] [Google Scholar]
- Sibley L. D., Krahenbuhl J. L., Adams G. M., Weidner E. Toxoplasma modifies macrophage phagosomes by secretion of a vesicular network rich in surface proteins. J Cell Biol. 1986 Sep;103(3):867–874. doi: 10.1083/jcb.103.3.867. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Véscovi E. G., Ayala Y. M., Di Cera E., Groisman E. A. Characterization of the bacterial sensor protein PhoQ. Evidence for distinct binding sites for Mg2+ and Ca2+. J Biol Chem. 1997 Jan 17;272(3):1440–1443. doi: 10.1074/jbc.272.3.1440. [DOI] [PubMed] [Google Scholar]
- Worsham P. L., Goldman W. E. Quantitative plating of Histoplasma capsulatum without addition of conditioned medium or siderophores. J Med Vet Mycol. 1988 Jun;26(3):137–143. [PubMed] [Google Scholar]