Molecular cloning of a second phospholipase B gene, caPLB2 from Candida albicans 1

Abstract

Accumulating evidence suggests that phospholipase B, secreted by pathogenic fungi such as Candida albicans, Cryptococcus neoformans and Aspergillus fumigatus, functions as one of the virulence factors. In the present study, we have attempted to clone phospholipase B gene from C. albicans. By RT-PCR analysis with degenerate primers based on conserved regions of phospholipase B from Saccharomyces cerevisiae, Penicillium notatum and Torulaspora delbrueckii two similar but different cDNA fragments were obtained. One corresponded to the partial sequence of caPLB1, recently cloned phospholipase B gene from C. albicans by a different approach (Leidich et al.: J Biol Chem 1998; 273: 26078-86). The other fragments contained sequences similar to the corresponding sequences of phospholipase B from other fungi. The presence of two related genes was confirmed by Southern and Northern blot analyses. The full length of the second C. albicans phospholipase B gene (caPLB2) encoded a putative protein with 608 amino acids and contained a potential signal peptide sequence and a putative catalytic region, which are found in phospholipase B from other fungi. Consistent with the findings of caPLB1, caPLB2 also lacks a cluster of hydrophobic amino acids at the COOH-terminal, which may function as a signal of glycosylphosphatidylinositol anchor.

Purification and Characterization of Phospholipase B fromCandida utilis

“…PCR amplification was performed using degenerate oligonucleotide primers designed on the basis of the highly conserved amino acid sequences found in S. cerevisiae PLB1, 10) T. delbrueckii PLB, 17) C. albicans PLB1, 13) and C. albicans PLB2. 14) The following primers were synthesized: forward primer,…”

“…A pathogenic yeast, Candida albicans, contained two PLB genes (caPLB1 and caPLB2). 13,14) The virulence of the yeast was significantly attenuated by the disruption of caPLB1, compared with the isogenic wild-type parental strain. 13) Accordingly, PLB activity has been identified as a potential virulence factor in C. albicans.…”

Candida albicansCell Wall Proteins

“…The strain also showed attenuated virulence in a murine disseminated infection model. PLB2 has been cloned and expression was detected in rich medium (Northern analysis [370]). The gene has not been deleted.…”

Robust Utilization of Phospholipase-Generated Metabolites, Glycerophosphodiesters, by Candida albicans: Role of the CaGit1 Permease

“…Most fungal cells, including those of Candida albicans and Saccharomyces cerevisiae, contain multiple phospholipase B (PLB)-encoding genes (25) that act on both fatty acyl ester groups to produce glycerophosphodiesters, such as glycerophosphocholine (GroPCho) and glycerophosphoinositol (GroPIns) (34). The potential role of C. albicans PLBs as virulence factors has been explored by others (21,26,29,30,40). For example, C. albicans strains exhibiting elevated PLB activity have been shown to be associated with increased virulence in mouse models of disseminated candidiasis (22).…”