Abstract
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.
Original language | English |
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Pages (from-to) | 1590-5 |
Number of pages | 6 |
Journal | Science |
Volume | 336 |
Issue number | 6088 |
DOIs | |
Publication status | Published - 22 Jun 2012 |
Keywords
- Actin Cytoskeleton
- Actins
- Cell Membrane
- Diffusion
- Fungal Proteins
- Magnaporthe
- Microfilament Proteins
- Mutation
- Oryza
- Phosphatidylinositols
- Plant Diseases
- Plant Leaves
- Protein Interaction Domains and Motifs
- Recombinant Fusion Proteins
- Septins
- cdc42 GTP-Binding Protein