title: A STE12 homolog is required for mating but dispensable for filamentation in candida lusitaniae.
abstract: Candida lusitaniae is a dimorphic yeast that is emerging as an opportunistic fungal pathogen. In contrast to Candida albicans, which is diploid and asexual, C. lusitaniae has been reported to have a sexual cycle. We have employed genetic approaches to demonstrate that C. lusitaniae is haploid and has a sexual cycle involving mating between MATa and MATalpha cells under nutrient deprivation conditions. By degenerate PCR, we identified a C. lusitaniae homolog (Cls12) of the Ste12 transcription factor that regulates mating, filamentation, and virulence in Saccharomyces cerevisiae, C. albicans, and Cryptococcus neoformans. Comparison of the CLS12 DNA and protein sequences to other STE12 homologs and transformation experiments with selectable markers from S. cerevisiae (URA3, KanMX, HphMX) and C. albicans (CaURA3) provide evidence that the CUG codon encodes serine instead of leucine in C. lusitaniae, as is also the case in C. albicans. The C. lusitaniae CLS12 gene was disrupted by biolistic transformation and homologous recombination. C. lusitaniae cls12 mutant strains were sterile but had no defect in filamentous growth. Our findings reveal both conserved and divergent roles for the C. lusitaniae STE12 homolog in regulating differentiation of this emerging fungal pathogen.
authors.affiliation: Department of Genetics, Pharmacology and Cancer Biology, Microbiology, and Medicine, Howard Hughes Medical Institute, Duke University Medical Center, Durham, North Carolina 27710, USA.
authors.forename: L Y
authors.initials: LY
authors.lastname: Young
authors.forename: M C
authors.initials: MC
authors.lastname: Lorenz
authors.forename: J
authors.initials: J
authors.lastname: Heitman
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002175:Candida / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D003513:Cycloheximide / Q000494:pharmacology; D004271:DNA, Fungal; D004352:Drug Resistance, Microbial; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D005800:Genes, Fungal; D007930:Leucine / Q000235:genetics; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009584:Nitrogen / Q000378:metabolism; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D011995:Recombination, Genetic; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D012694:Serine / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics
chemical_list: C410298:CLS12 protein, Clavispora lusitaniae; D004271:DNA, Fungal; D005656:Fungal Proteins; D011500:Protein Synthesis Inhibitors; C489241:STE12 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D012694:Serine; D003513:Cycloheximide; D007930:Leucine; D009584:Nitrogen