[Molecular characterization of a 70 kDa heat shock protein [HSP70] gene in dermatophyte pathogen T.verrucosum]

ABSTRACT

Trichophyton verrucosum [T.verrucosum] is one of the dermatophyte fungi which invades the skin of human and animals particularly cattle. Several properties of this fungus have been investigated so far. However a few studies were carried out in the field of molecular biology of this fungus. In the present study we tried to identify the chaperone proteins related to the 70 kDa heat shock proteins [HSP70] in this fungus and study of its gene regulation under heat-stress conditions. Pairs of 21 and 20 nt primers were designed from highly conserved regions of the similar genes in other fungi. Mentioned primers were utilized in PCR by using isolated genomic DNA and cDNA of T.verrucosum whereas the PCR fragments were then sequenced. Eventually, 2217 nucleotides have been sequenced from this new gene which has two introns and encodes a polypeptide with 654 amino acids. Sequences comparison in gene data banks [NCBI, NIH] for both the complete DNA and its deduced amino acid revealed significant homology with members of the eukaryotic 70 kDa HSP family. Further investigation revealed that the expression of this new gene increases under heat-stress conditions. This new gene has similarity with other genes of the same family in other organisms. This protein could efficiently protect the microorganism against heat stress