The effect of griseofulvin on the gene regulation of β-tubulin in the dermatophyte pathogen Trichophyton rubrum

Griseofulvin – a mold metabolite produced by Penicillium griseofulvum – is an antifungal drug whose interaction with tubulin is poorly understood. In this study we cloned the β-tubulin gene in Trichophyton rubrum, which encodes a polypeptide with 447 amino acids (accession number AAV33733). Nucleotide sequence comparison in data banks for both the partial DNA and its deduced amino acid sequence revealed significant homology with members of the eukaryotic β-tubulin gene family. Investigation based on real-time polymerase chain reaction (PCR) indicated that griseofulvin treatment of T. rubrum fungal cells decreased the expression of the β-tubulin gene in a dose-dependent manner. However, fluconazole had no effect on the β-tubulin transcript level under the same circumstances. The identification of this vital gene, which is potentially involved in many cellular functions in pathogenic dermatophyte fungi, is the first step towards understanding the functional characteristics of β-tubulin in such fungi and may help in the development of new antifungal drugs against dermatophytes.