Functional analysis of CaRAP1, encoding the Repressor/activator protein 1 of Candida albicans

• Published in: Gene 2003-03, Vol.307 (C), p.151-158
• Main Authors: Biswas, Kajal, Rieger, Klaus-Jörg, Morschhäuser, Joachim
• Format: Article
• Language: English
• Subjects: Candida albicans - genetics; Candida albicans - growth & development; Cell Division - genetics; Cell Division - physiology; Fungal Proteins - genetics; Fungal Proteins - physiology; Gene Deletion; Genes, Essential - genetics; Genetic Complementation Test; Mutation; Phenotype; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - growth & development; Telomere-Binding Proteins - genetics; Telomere-Binding Proteins - physiology; Transcription Factors - genetics; Transcription Factors - physiology
• ISSN: 0378-1119
• DOI: 10.1016/S0378-1119(03)00456-6

The RAP1 gene (repressor/activator protein 1) encodes a transcription factor and telomere binding protein that is essential for viability in the budding yeast Saccharomyces cerevisiae. The genome sequence of the opportunistic fungal pathogen Candida albicans contains a RAP1 homologue. We generated C. albicans mutants in which both RAP1 alleles were deleted. The Deltarap1 mutants grew as well as the wild-type parental strain and formed normal germ tubes and hyphae in response to a variety of inducing conditions. However, under conditions that promote budding yeast growth in the wild-type strain, the Deltarap1 mutants formed both yeast and pseudohyphal cells. This phenotype was reverted upon reintroduction of a functional RAP1 copy. Our results demonstrate that RAP1 is a non-essential gene in C. albicans which is required to repress the formation of pseudohyphae under conditions favouring growth as budding yeast.