Functional analysis of the promoter of the phase-specific WH11 gene of Candida albicans.
Candida albicans WO-1 switches spontaneously, frequently, and reversibly between a hemispherical white and a flat gray (opaque) colony-forming phenotype. This transition affects a number of morphological and physiological parameters and involves the activation and deactivation of phase-specific genes. The WH11 gene is transcribed in the white but not the opaque phase. A chimeric WH11-firefly luciferase gene containing the 5' upstream region of WH11 was demonstrated to be under phase regulation regardless of the site of integration, and a series of promoter deletion constructs was used to delineate two white-phase-specific transcription activation domains. Gel retardation experiments with the individual distal or proximal domain and white-phase or opaque-phase protein extract demonstrated the formation of one distal white-phase-specific complex and two proximal white-phase-specific complexes. Specific subfragments were tested for their ability to compete with the entire domain in the formation of complexes with white-phase protein extract in order to map the proximal domain sequence involved in white-phase-specific complex formation. Our results indicate that white-phase-specific transcription of WH11 is positively regulated by trans-acting factors interacting with two cis-acting activation sequences in the WH11 promoter.
Srikantha
T
T
Department of Biological Sciences, University of Iowa, Iowa City 52242.
Chandrasekhar
A
A
Soll
D R
DR
D000818:Animals; D001483:Base Sequence; D002176:Candida albicans / Q000166:cytology / Q000235:genetics* / Q000254:growth & development; D001517:Coleoptera; D005656:Fungal Proteins / Q000096:biosynthesis* / Q000235:genetics; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D008156:Luciferases / Q000096:biosynthesis; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D012045:Regulatory Sequences, Nucleic Acid; D017384:Sequence Deletion; D014158:Transcription, Genetic
D005656:Fungal Proteins; D011993:Recombinant Fusion Proteins; C083140:Wh11 protein, Candida albicans; D008156:Luciferases