Reduced virulence of Candida albicans mutants lacking the GNA1 gene encoding glucosamine-6-phosphate acetyltransferase

The yeast GNA1 gene encodes glucosamine-6-phosphate acetyltransferase which catalyses the reaction of glucosamine 6-phosphate with acetyl-CoA to form N-acetylglucosamine 6-phosphate, a fundamental precursor in UDP-N-acetylglu cosamine biosynthesis. Candida albicans mutants lacking GNA1 were viable in the presence of N-acetylglucosamine. To confirm the physiological importan ce of C. albicans GNA1, the virulence of a C. albicans gna1 Delta null muta nt was examined in a mouse model of candidiasis. When injected intravenousl y into mice, the virulence of the C. albicans gna1 Delta null mutant was si gnificantly attenuated. The reduced virulence appeared to be the result of rapid clearance from host tissue. These data suggest that C. albicans GNA1 is required for survival of the fungus in host animals, probably because an insufficient level of N-acetylglucosamine is available from the host tissu es.