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A new non-hydrophobic cell wall protein (CWP10) of Metarhizium anisopliae enhances conidial hydrophobicity when expressed in Beauveria bassiana

Li, Jun, Ying, Sheng-Hua, Shan, Le-Tian, Feng, Ming-Guang
Applied microbiology and biotechnology 2010 v.85 no.4 pp. 975-984
conidia, heat tolerance, Metarhizium anisopliae, cell walls, Beauveria bassiana, formic acid, cytoplasm, adhesion, hydrophobicity, signal peptide, introns
A cell wall protein, CWP10, resolved from the conidial formic acid extract of a Metarhizium anisopliae isolate, was characterized as a new 9.9-kDa protein with a 32-aa signal peptide with a central hydrophobic region (ca. 10 residues) at its N-terminus. This protein was proven neither to be hydrophobic nor glycosylated and encoded by a 363-bp, single-copy gene with three introns. CWP10 was existent in the conidial extracts of seven of 18 tested M. anisopliae isolates and much more abundant (immunogold-labeled) on conidial walls than in cytoplasm. Integrating the gene into a CWP10-absent strain of Beauveria bassiana led to excellent expression of CWP10 in aerial conidia, increasing net conidial hydrophobicity by 10.8% or adhesion to hydrophobic Teflon by 1.3-fold. However, the expressed protein had no effect on conidial tolerance to thermal and ultraviolet stresses. This is the first report on a non-hydrophobic cell-wall protein enhancing conidial hydrophobicity and adhesion of the fungal species.