The Characteristic of a Novel Metalloproteinase from Puccinia Helianthi

Abstract Objective In phytopathogenic fungi, several metalloproteinase have been implicated in virulence, but pathogenesis roles in rust are largely unknown. Here, we identified a M36 family metalloproteases from Puccina helianthi genome, designated PhMEP1, aimed to reveal the biological characteristics related to pathogenicity.Result Bioinformatics analysis showed that PhMEP1contains some of the conserved zinc-binding and active site motifs characteristics of metalloproteinase which might well be a new fungalysin-like peptidase in the M36 family. The PhMEP1 protein was over expressed as inclusion bodies in Escherichia coli. The recombinant expression products of PhMEP1 could hydrolyze azocasein and the hydrolytic activity was suppressed by metal ion chelating agents such as 1,10-phenanthroline and ethylene diamine tetraacetic acid (EDTA). The subcellular localization of PhMEP1 was detected by confocal laser scanning microscopy of the leaves from a 2-day-old Nicotiana benthamiana seedlings expressed PhMEP1-GFP fusion that showed green fluorescent protein (GFP) signal accumulated in the plasma membrane of epithelial cells.Conclusion PhMEP1 may serve as a pathogenicity factor contributing to P. helianthi penetration and infection.