Cloning and characterization of a gene (LIP1) which encodes a lipase from the pathogenic yeast Candida albicans

This 1997 study describes the cloning and characterization of a lipase gene (LIP1) from the pathogenic yeast Candida albicans. Researchers screened a C. albicans genomic library in Saccharomyces cerevisiae using egg-yolk agar plates and identified two clones exhibiting lipolytic activity. Sequence analysis revealed a 1053 base pair open reading frame encoding a 351 amino acid protein with a predicted molecular weight of 38 kDa. Although showing limited overall homology to known proteins, the enzyme contained the characteristic Gly-X-Ser-X-Gly motif found in lipases and showed conservation with fungal lipases. Functional analysis confirmed the enzyme acts as a lipase, hydrolyzing triglycerides but not phospholipids. Northern blot analysis demonstrated that LIP1 expression was induced specifically when C. albicans was grown on media containing lipid sources (Tween 80, other Tweens, or triglycerides) as the sole carbon source, and was repressed by carbohydrate supplementation. Southern blot analysis suggested the presence of a lipase gene family in C. albicans and related species. This work provides the foundation for generating LIP1-deficient mutants to determine the enzyme's role in candidal virulence.

Key findings

• Researchers cloned and sequenced a novel lipase gene (LIP1) from C. albicans encoding a 351 amino acid protein with characteristic lipase motifs.
• The LIP1 gene product hydrolyzes triglycerides but not phospholipids, confirming it functions as a true lipase rather than phospholipase.
• LIP1 expression is tightly regulated, induced only in the presence of lipid carbon sources (Tweens or triglycerides) and repressed by carbohydrates.
• Southern blot analysis revealed a lipase gene family in C. albicans and homologous sequences in other Candida species but not in S. cerevisiae.