Ste18p is a positive control element in the mating process of Candida albicans.
Heterotrimeric G proteins are an important class of eukaryotic signaling molecules that have been identified as central elements in the pheromone response pathways of many fungi. In the fungal pathogen Candida albicans, the STE18 gene (ORF19.6551.1) encodes a potential γ subunit of a heterotrimeric G protein; this protein contains the C-terminal CAAX box characteristic of γ subunits and has sequence similarity to γ subunits implicated in the mating pathways of a variety of fungi. Disruption of this gene was shown to cause sterility of MTLa mating cells and to block pheromone-induced gene expression and shmoo formation; deletion of just the CAAX box residues is sufficient to inactivate Ste18 function in the mating process. Intriguingly, ectopic expression behind the strong ACT1 promoter of either the Gα or the Gβ subunit of the heterotrimeric G protein is able to suppress the mating defect caused by deletion of the Gγ subunit and restore both pheromone-induced gene expression and morphology changes.
Center for New Drug Research, Department of Pharmacology, School of Pharmacy, Second Military Medical University, Shanghai, China.
Hui
H
Lu
Yuan
Y
Sun
Yuan-Ying
YY
Jiang
Malcolm
M
Whiteway
D000595:Amino Acid Sequence; D002176:Candida albicans / Q000235:genetics* / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D044388:GTP-Binding Protein gamma Subunits / Q000235:genetics* / Q000378:metabolism; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D049770:Genes, Mating Type, Fungal; D008969:Molecular Sequence Data; D010675:Pheromones / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction
D005656:Fungal Proteins; D044388:GTP-Binding Protein gamma Subunits; D010675:Pheromones