Structure and self-assembly of MPG1, a hydrophobin from the rice blast fungus — ASN Events
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  2. Session 12: Poster Session D - Including Happy Hour & Trade Display
  3. Structure and self-assembly of MPG1, a hydrophobin from the rice blast fungus

Structure and self-assembly of MPG1, a hydrophobin from the rice blast fungus (#402)

Chi Le Lan Pham 1 , Margaux Soulès 1 , Anthony Rey 2 , Ann Kwan 3 , Margie Sunde 1
  1. Discipline of Pharmacology, School of Medical Sciences, The University of Sydney, Camperdown, NSW, Australia
  2. Centre for Vascular Research, University of New South Wales, Sydney, NSW, Australia
  3. School of Molecular Bioscience, The University of Sydney, Camperdown, NSW, Australia

Hydrophobins are a class of small proteins characterised by eight conserved cysteines which form four intra-molecular disulphide bonds. The proteins are unique to filamentous fungi and are able to spontaneously self-assemble into an amphipathic, amyloid rodlet-containing monolayer at hydrophobic:hydrophilic interfaces. MPG1 is a hydrophobin from the fungal pathogen Magnaporthe grisea that causes rice blast, one of the most devastating diseases of the rice plant. Expression of MPG1 is essential for correct formation and maturation of specialised infectious structures known as appressoria. The spores of M. grisea are covered by MPG1 amyloid rodlet layers which assist with spore attachment to, as well as the infection of, the rice leaf. Therefore, an in-depth understanding of the structure and assembly mechanism of MPG1 will allow the development of new strategies that fight against infection by M. grisea.
We have determined the solution structure of MPG1 monomer by NMR spectroscopy. Based on the structure, targeted site-directed mutagenesis was used to identify residues within MPG1 that are critical for the self-assembly of MPG1 into the rodlet layer. In addition, the mechanism of rodlet assembly was tested under various experimental conditions. We have also investigated the effect of surface tension on MPG1 self-assembly at a hydrophobic:hydrophilic interface. Our results yield insights for the development of inhibitors of the rodlet assembly process and the rodlet:rice leaf interactions which could be used to reduce the infectivity of M. grisea.