Septin-mediated plant cell invasion by the rice blast fungus, Magnaporthe oryzae.
To cause rice blast disease, the fungus Magnaporthe oryzae develops a pressurized dome-shaped cell called an appressorium, which physically ruptures the leaf cuticle to gain entry to plant tissue. Here, we report that a toroidal F-actin network assembles in the appressorium by means of four septin guanosine triphosphatases, which polymerize into a dynamic, hetero-oligomeric ring. Septins scaffold F-actin, via the ezrin-radixin-moesin protein Tea1, and phosphatidylinositide interactions at the appressorium plasma membrane. The septin ring assembles in a Cdc42- and Chm1-dependent manner and forms a diffusion barrier to localize the inverse-bin-amphiphysin-RVS-domain protein Rvs167 and the Wiskott-Aldrich syndrome protein Las17 at the point of penetration. Septins thereby provide the cortical rigidity and membrane curvature necessary for protrusion of a rigid penetration peg to breach the leaf surface.
School of Biosciences, University of Exeter, Exeter, UK.
SourceScience (New York, N.Y.) 336:6088 2012 Jun 22 pg 1590-5
Protein Interaction Domains and Motifs
Recombinant Fusion Proteins
cdc42 GTP-Binding Protein
Pub Type(s)Journal Article
Research Support, Non-U.S. Gov't