Defective Hyphal induction of a Candida albicans phosphatidylinositol 3-phosphate 5-kinase null mutant on solid media does not lead to decreased virulence.
A phosphatidylinositol 3-phosphate [PI(3)P] 5-kinase gene (CaFAB1) of the most important human pathogenic yeast, Candida albicans, was cloned and sequenced. An open reading frame was detected which encodes a 2,369-amino-acid protein with a calculated molecular mass of 268 kDa and a relative isoelectric point of 6.76. This protein exhibits 38% overall amino acid sequence identity with Saccharomyces cerevisiae Fab1p. We localized the CaFAB1 gene on chromosome R. To determine the influence of the PI(3)P 5-kinase CaFab1p on processes involved in C. albicans morphogenesis and pathogenicity, we sequentially disrupted both copies of the gene. Homozygous deletion of C. albicans CaFAB1 resulted in a mutant strain which exhibited defects in morphogenesis. A Cafab1 null mutant had enlarged vacuoles, an acidification defect, and increased generation times and was unable to form hyphae on different solid media. The sensitivities to hyperosmotic and high-temperature stresses, adherence, and virulence compared to those of wild-type strain SC5314 were not affected.
Department of Infection Biology, Hans Knöll Institute for Natural Products Research, D-07745 Jena, Germany.
Martin
M
Augsten
Claudia
C
Hübner
Monika
M
Nguyen
Waldemar
W
Künkel
Albert
A
Härtl
Raimund
R
Eck
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002176:Candida albicans / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development / Q000472:pathogenicity; D002177:Candidiasis; D002448:Cell Adhesion; D015825:Chromosomes, Fungal; D003001:Cloning, Molecular; D004271:DNA, Fungal; D004195:Disease Models, Animal; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009995:Osmosis; D018129:Phosphatidylinositol Phosphates; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014617:Vacuoles; D014774:Virulence
D004271:DNA, Fungal; D018129:Phosphatidylinositol Phosphates; D029701:Saccharomyces cerevisiae Proteins; C055525:phosphatidylinositol 3-phosphate; C095504:FAB1 protein, S cerevisiae; D017853:Phosphotransferases (Alcohol Group Acceptor)