THE GENES ENCODING THE SECRETED ASPARTYL PROTEINASES OF CANDIDA-ALBICANS CONSTITUTE A FAMILY WITH AT LEAST 3 MEMBERS

The secreted aspartyl proteinase activity from Candida albicans is thought to be a potential virulence factor. Four laboratories have cloned a gene from C. albicans encoding this enzyme. When two of these genes sharing 77% homology at the DNA level are hybridized under conditions of high stringency to contour-clamped homogeneous electric field chromosome separations of four different strains, they label different chromosomes: chromosome 6 for SAP1 and chromosome R for SAP2. The existence of different genes for the two sequences was confirmed by polymerase chain reaction. Genomic Southern blots probed with the genes and washed at low stringency revealed several cross-hybridizing bands. Contour-clamped homogeneous electric field chromosome separations probed at low stringency indicated that there was a cross-hybridizing sequence on chromosome 3 in addition to those on chromosomes R and 6. The genes for the secreted aspartyl proteinase activity in C. albicans thus constitute a gene family which we have called the SAP family.