Assembly of the fungal SC3 hydrophobin into functional amyloid fibrils depends on its concentration and is promoted by cell wall polysaccharides.
Class I hydrophobins function in fungal growth and development by self-assembling at hydrophobic-hydrophilic interfaces into amyloid-like fibrils. SC3 of the mushroom-forming fungus Schizophyllum commune is the best studied class I hydrophobin. This protein spontaneously adopts the amyloid state at the water-air interface. In contrast, SC3 is arrested in an intermediate conformation at the interface between water and a hydrophobic solid such as polytetrafluoroethylene (PTFE; Teflon). This finding prompted us to study conditions that promote assembly of SC3 into amyloid fibrils. Here, we show that SC3 adopts the amyloid state at the water-PTFE interface at high concentration (300 microg ml(-1)) and prolonged incubation (16 h). Moreover, we show that amyloid formation at both the water-air and water-PTFE interfaces is promoted by the cell wall components schizophyllan (beta(1-3),beta(1-6)-glucan) and beta(1-3)-glucan. Hydrophobin concentration and cell wall polysaccharides thus contribute to the role of SC3 in formation of aerial hyphae and in hyphal attachment.
Scholtmeijer
Karin
K
BioMaDe Technology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands. K.Scholtmeijer@uu.nl
de Vocht
Marcel L
ML
Rink
Rick
R
Robillard
George T
GT
Wösten
Han A B
HA
D000682:Amyloid / Q000737:chemistry / Q000378:metabolism*; D002473:Cell Wall / Q000737:chemistry; D002942:Circular Dichroism; D004591:Electrophoresis, Polyacrylamide Gel; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism*; D005936:Glucans / Q000737:chemistry / Q000378:metabolism; D057927:Hydrophobic and Hydrophilic Interactions; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism*; D011138:Polytetrafluoroethylene / Q000737:chemistry; D017433:Protein Structure, Secondary; D012567:Schizophyllum / Q000378:metabolism*; D014867:Water / Q000737:chemistry
D000682:Amyloid; D005656:Fungal Proteins; D005936:Glucans; D011134:Polysaccharides; D014867:Water; C003045:paramylon; D011138:Polytetrafluoroethylene