title: Alpha-pheromone-induced "shmooing" and gene regulation require white-opaque switching during Candida albicans mating.
abstract: A 14-mer alpha-pheromone peptide of Candida albicans was chemically synthesized and used to analyze the role of white-opaque switching in the mating process. The alpha-pheromone peptide blocked cell multiplication and induced "shmooing" in a/a cells expressing the opaque-phase phenotype but not in a/a cells expressing the white-phase phenotype. The alpha-pheromone peptide induced these effects at 25 degrees C but not at 37 degrees C. An analysis of mating-associated gene expression revealed several categories of gene regulation, including (i) MTL-homozygous-specific, pheromone stimulated, switching-independent (CAG1 and STE4); (ii) mating type-specific, pheromone-induced, switching-independent (STE2); and (iii) pheromone-induced, switching-dependent (FIG1, KAR4, and HWP1). An analysis of switching-regulated genes revealed an additional category of opaque-phase-specific genes that are downregulated by alpha-pheromone only in a/a cells (OP4, SAP1, and SAP3). These results demonstrate that alpha-pheromone causes shmooing, the initial step in the mating process, only in a/a cells expressing the opaque phenotype and only at temperatures below that in the human host. These results further demonstrate that although some mating-associated genes are stimulated by the alpha-pheromone peptide in both white- and opaque-phase cells, others are stimulated only in opaque-phase cells, revealing a category of gene regulation unique to C. albicans in which alpha-pheromone induction requires the white-opaque transition. These results demonstrate that in C. albicans, the mating process and associated gene regulation must be examined within the context of white-opaque switching.
authors.affiliation: Department of Biological Sciences, University of Iowa, Iowa City, Iowa 52242-1324, USA.
authors.forename: Shawn R
authors.initials: SR
authors.lastname: Lockhart
authors.forename: Rui
authors.initials: R
authors.lastname: Zhao
authors.forename: Karla J
authors.initials: KJ
authors.lastname: Daniels
authors.forename: David R
authors.initials: DR
authors.lastname: Soll
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics; D000595:Amino Acid Sequence; D016282:Aspartic Acid Endopeptidases / Q000235:genetics; D015152:Blotting, Northern; D002176:Candida albicans / Q000187:drug effects / Q000235:genetics* / Q000502:physiology; D002455:Cell Division / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D022081:Cell Surface Extensions / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D005656:Fungal Proteins / Q000235:genetics; D019204:GTP-Binding Proteins / Q000235:genetics; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects*; D000072235:Mating Factor; D008562:Membrane Glycoproteins / Q000235:genetics; D008954:Models, Biological; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000494:pharmacology* / Q000502:physiology; D010641:Phenotype; D051964:Receptors, Mating Factor; D018000:Receptors, Peptide / Q000235:genetics; D013696:Temperature; D014157:Transcription Factors
chemical_list: D018528:ATP-Binding Cassette Transporters; C109399:Cdr3 protein, Candida albicans; D005656:Fungal Proteins; C118102:HWP1 protein, Candida albicans; D008562:Membrane Glycoproteins; D010455:Peptides; D051964:Receptors, Mating Factor; D018000:Receptors, Peptide; D014157:Transcription Factors; C074148:CAG1 protein, Candida albicans; D000072235:Mating Factor; D016282:Aspartic Acid Endopeptidases; C086390:SAP1 protein, Candida albicans; C090754:SAP3 protein, Candida albicans; C116371:Sap9 protein, Candida albicans; D019204:GTP-Binding Proteins