Cloning and disruption of caPLB1, a phospholipase B gene involved in the pathogenicity of Candida albicans

Steven D. Leidich, Ashraf S. Ibrahim, Yue Fu, Anjni Koul, Chad Jessup, John Vitullo, William Fonzi, Fariba Mirbod, Shigeru Nakashima, Yoshinori Nozawa, Mahmoud A. Ghannoum

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Abstract

The Candida albicans PLB1 gene was cloned using a polymerase chain reaction-based approach relying on degenerate oligonucleotide primers designed according to the amino acid sequences of two peptide fragments obtained from a purified candidal enzyme displaying phospholipase activity (Mirbod, F., Banno, Y., Ghannoum, M. A., Ibrahim, A. S., Nakashima, S., Yasuo, K., Cole, G.T., and Nozawa, Y. (1995) Biochim. Biophys. Acta 1257, 181-188). Sequence analysis of a 6.7-kilobase pair EcoRI-ClaI genomic clone revealed a single open reading frame of 1818 base pairs that predicts for a preprotein of 605 residues. Comparison of the putative candidal phospholipase with those of other proteins in data base revealed significant homology to known fungal phospholipase Bs from Saccharomyces cerevisiae (45%), Penicillium notatum (42%), Torulaspora delbrueckii (48%), and Schizosaccharomyces pombe (38%). Thus, we have cloned the gene encoding a C. albicans phospholipase B homolog. This gene, designated caPLB1, was mapped to chromosome 6. Disruption experiments revealed that the caplb1 null mutant is viable and displays no obvious phenotype. However, the virulence of strains deleted for caPLB1, as assessed in a murine model for hematogenously disseminated candidiasis, was significantly attenuated compared with the isogenic wild-type parental strain. Although deletion of caPLB1 did not produce any detectable effects on candidal adherence to human endothelial or epithelial cells, the ability of the caplb1 null mutant to penetrate host cells was dramatically reduced. Thus, phospholipase B may well contribute to the pathogenicity of C. albicans by abetting the fungus in damaging and traversing host cell membranes, processes which likely increase the rapidity of disseminated infection.

Original languageEnglish (US)
Pages (from-to)26078-26086
Number of pages9
JournalJournal of Biological Chemistry
Volume273
Issue number40
DOIs
StatePublished - Oct 2 1998
Externally publishedYes

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ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Cite this

Leidich, S. D., Ibrahim, A. S., Fu, Y., Koul, A., Jessup, C., Vitullo, J., Fonzi, W., Mirbod, F., Nakashima, S., Nozawa, Y., & Ghannoum, M. A. (1998). Cloning and disruption of caPLB1, a phospholipase B gene involved in the pathogenicity of Candida albicans. Journal of Biological Chemistry, 273(40), 26078-26086. https://doi.org/10.1074/jbc.273.40.26078