AO, FR Cell Cycle inhibitor and ML designed the research. MN, VT, AO and ML performed the experiments. FR and AO analyzed the data and wrote the paper. All authors read and approved the final manuscript.”
“Background Hydrophobins are small secreted proteins, produced only by filamentous fungi, which forms amphipathic layers on the outer surface of fungal cell walls [1, 2]. The hydrophobic side of the amphipathic layer is exposed to the outside environment, while the hydrophilic side is directed towards cell wall polysaccharides [1, 2]. Hydrophobins are characterized by the presence of eight conserved cysteine (Cys) residues

in a typical pattern [1–3]. Apart from this, they show very limited amino acid sequence similarity ML323 cost with each other. The Cys residues form four intra-molecular disulphide bridges suggested to prevent self-assembly of the hydrophobins in the absence of a hydrophilic-hydrophobic interface [1, 2]. Based on distinct hydropathy patterns and the type of layer they form, hydrophobins

are divided in to two classes [1–3]. Recent bioinformatic analyses have identified an intermediate class of hydrophobins in Trichoderma and Aspergillus species [4, 5]. Class I hydrophobins form amyloid-like rodlets that are highly insoluble in water, organic solvents and detergents like SDS and require strong acids for solubilisation, while amphipathic monolayers formed by class II hydrophobins lack the fibrillar rodlets and can be dissolved in aqueous organic solvents and detergents [1, 2]. Another distinguishing characteristic of hydrophobins is the specific spacing patterns of conserved Cys residues; the consensus Cys spacing pattern C-X5-10-CC-X33-41-C-X16-25-C-X5- CC-X13-17-C of Class I differs from the consensus Cys spacing pattern C-X9-10-CC-X11-C-X16-C-X8-9- CC-X10-C stiripentol of Class II [3–5].

Hydrophobins act as natural surfactants and reduce the surface tension of the medium, and perform a variety of biological functions in the life cycle of filamentous fungi. These include formation of a protective layer surrounding the hyphae and sexual structures, development of aerial hyphae, sporulation and spore dispersal, and fruit body formation [1–3]. In addition, hydrophobins mediate contact and communication between the fungus and its environments; that can include recognition and adhesion to host surfaces, and development of penetration structures during pathogenic and symbiotic interactions [3, 6, 7]. Hydrophobin MPG1 of the rice blast fungus Magnaporthe oryzae is necessary for leaf surface attachment and appresorium formation [8], while another hydrophobin MHP1, of the same fungus is involved in the late stage of pathogenesis [9]. In the entomopathogenic fungus Beauveria bassiana, deletion of hydrophobin genes results in decreased spore hydrophobicity and adhesion, loss of water-mediated dispersal, and lowered virulence to 17DMAG insects [10].