The pathogenic yeast Candida albicans is the frequent cause of fungal infections in immune-compromised patient populations. Infections are usually treated with antifungal drugs, such as azoles. Due to the extensive use of the drug in these patient populations, azole resistance is a significant and growing problem. Although the major mechanisms of drug resistance are known, little is known about the regulation of the genes involved in azole resistance. In order to better understand the regulation of ERG11, the gene encoding the target of azole drugs, functional analysis have been performed with the ERG11 gene promoter. An azole inducible element was isolated between 200-300 base pairs upstream of the start codon. In order to further define the azole inducible region, three additional inducible elements (225, 250, and 275 base pairs upstream of the start codon) have been created. Electrophoretic mobility shift assays (EMSA) are being performed on this region in order to identify transcription factors that interact with the azole inducible region. EMSA analysis will also elucidate the sequence to which the transcription factors bind. Four overlapping oligos were constructed corresponding to azole inducible region of the ERG11 promoter. EMSA analysis reveals the presence of several proteins that specifically interact with the first three oligos, all displaying a similar pattern. An unrelated pattern is observed for the fourth oligo. Sequence analysis reveals the presence of a common sequence within three of these oligos, which may account for a the common banding pattern shared between them. Further studies will be performed in order to determine the identity of the DNA binding proteins and the specific sequence to which they bind will be futher dissected by both EMSA and functional analysis.
Full conference title:
The 15 th Congress of the International Society for Human and Animal Mycology
- ISHAM 15th (2003)