The N-terminal region of Aspergillus oryzae hydrophobin RolA is important for RolA-cutinae CutL1 interaction

Toru Takahashi1, Kenji Uehara2, Yohei Yamagata2, Katsuya Gomi2, Fumihiko Hasegawa1, Keietsu Abe

Author address: 

1New Industry Creation Hatchery Center, Tohoku University, Sendai, Miyagi, Japan, 2Graduate School of Agricultural Science, Tohoku University, Sendai, Miyagi, Japan

Abstract: 

When fungi grow on plant or insect surfaces coated with wax polyesters that protect against pathogens, the fungi generally form aerial hyphae to contact the surfaces. Aerial structures such as hyphae and conidiophores are coated with hydrophobins, which are surface-active proteins involved in adhesion to hydrophobic surfaces. When the industrial fungus Aspergillus oryzae is cultivated in a liquid medium containing the biodegradable polyester polybutylene succinate-coadipate (PBSA), the rolA gene encoding a Type I hydrophobin RolA is highly transcribed. High levels of RolA are localized on the cell surface and also secreted into the liquid medium. Under these conditions, A. oryzae simultaneously produces the cutinase CutL1, which hydrolyzes PBSA. RolA adsorbed to the hydrophobic surface of PBSA particles in the medium recruits CutL1, resulting in condensation of CutL1 on the PBSA surface and consequent stimulation of PBSA hydrolysis (1, 2). The ability that RolA attached to the PBSA surfaces recruits esterase CutL1 is a newly discovered function in hydrophobin (1). In the present study, we studied amino acid residues involved in the RolA-CutL1 interaction by means of site-directed mutagenesis and chemical modification of RolA. Teflon particles were coated with RolA and its derivatives. The Teflon particles coated with RolA or its derivatives were incubated with soluble CutL1 for recruitment, and then the supernatant and particles were separated by centrifugation. Recruited CutL1 was extracted from the centrifuged particles with SDS and quantitatively measured by SDS-PAGE analyses. We found that the N-terminal region of RolA is important for RolA-CutL1 interaction. We discuss amino acid residues involved in the interaction
2008

abstract No: 

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Full conference title: 

9th EUROPEAN CONFERENCE ON FUNGAL GENETICS
    • ECFG 9th (2008)