Microsporum canis is a well-known major agent of dermatophytosis in dogs and cats, causing a zoonosis. A previously purified M. canis 43.5 kDa extracellular keratinolytic metalloprotease has been pointed out as one of the virulence-related factors. Using a polymerase chain reaction (PCR), we isolated one cDNA clone and the gene encoding this enzyme. The nucleotide sequence of this gene, designated MCMP1, matched exactly with the cDNA sequence, except for the four introns included in the open reading frame. The MCMP1 cDNA encodes a signal sequence and 228 additional amino acid residues preceding the sequence for the mature protein composed of 246 amino acid residues. The deduced amino acid sequence of the mcmp1 cDNA was highly identical with Aspergillus fumigatus metalloprotease (MEP), and contained the HEXXH sequence that is highly conserved in zinc metalloprotease gene family. Then, we amplified a 1 kb fragment, 5’-upstream of the mcmp1 gene by inverse PCR. A TATA motif was found in the nucleotide sequence. Recently, it is revealed that both the MCMP1 gene and the M. canis metalloprotease gene (MEP3) encode an identical enzyme. MEP3 is shown as an active keratinolytic enzyme to be induced during invasion by dermatophytes. Therefore, an analysis of the regulatory sequence may be a first step for us to elucidate a molecular basis for regulatory system of gene expression that occurs in dermatophytosis.
Full conference title:
The 15 th Congress of the International Society for Human and Animal Mycology
- ISHAM 15th (2003)