Mining the Phytophthora infestans genome for metalloproteases

Phytophthora infestans is a notorious plant pathogenic oomycete that causes late blight of potato and tomato. The molecular mechanisms exploited by P. infestans in order to circumvent host defence are not fully understood. In several pathogens, proteases are known that can modify host proteins and in this way, play an important role in virulence. Metalloproteases (MPs) are named after the presence of a metal ion at their catalytic site. In mammalian systems, members of the Matrix Metalloprotease (MMP) family and A Disintegrin And Metalloprotease (ADAM) family of MPs have been reported to modify transmembrane proteins during a process called ectodomain shedding. In order to study the potential role of MPs in Phytophthora virulence, an inventory of P. infestans MPs was made based on genome mining. The predicted gene models were verified using ESTs and transcriptomics data. This resulted in a total of 105 P. infestans MP genes that could be classified into 20 different MP families. However, none of the P. infestans MPs could be grouped into either the ADAM or MMP family. Further analyses of the domain compositions and phylogenetic relationships will give 32 insight into the evolution of MPs in P. infestans and related oomycetes. Expression profiles of P. infestans MPs during various growth and infection stages of P. infestans will be obtained from existing transcriptomics data in order to select candidates for functional analysis.