TY - JOUR
T1 - Aspergillus Hydrophobins
T2 - Physicochemical Properties, Biochemical Properties, and Functions in Solid Polymer Degradation
AU - Tanaka, Takumi
AU - Terauchi, Yuki
AU - Yoshimi, Akira
AU - Abe, Keietsu
N1 - Funding Information:
This work was partly supported by a Grant-in-Aid for Scientific Research (B) from the Japan Society for the Promotion of Science (grant number 17H03787 to K.A.), a Grant-in-Aid for Japan Society for the Promotion of Science Fellows (grant number 18J11900 to Y.T.), and the Institute for Fermentation, Osaka, Japan (grant number K-2019-002 to A.Y.). T.T. is also supported by the Institute for Fermentation, Osaka, Japan (grant number K-2021-008 to Ken-ichi Kusumoto at Osaka University).
Publisher Copyright:
© 2022 by the authors.
PY - 2022/8
Y1 - 2022/8
N2 - Hydrophobins are small amphipathic proteins conserved in filamentous fungi. In this review, the properties and functions of Aspergillus hydrophobins are comprehensively discussed on the basis of recent findings. Multiple Aspergillus hydrophobins have been identified and categorized in conventional class I and two non-conventional classes. Some Aspergillus hydrophobins can be purified in a water phase without organic solvents. Class I hydrophobins of Aspergilli self-assemble to form amphipathic membranes. At the air–liquid interface, RolA of Aspergillus oryzae self-assembles via four stages, and its self-assembled films consist of two layers, a rodlet membrane facing air and rod-like structures facing liquid. The self-assembly depends mainly on hydrophobin conformation and solution pH. Cys4–Cys5 and Cys7–Cys8 loops, disulfide bonds, and conserved Cys residues of RodA-like hydrophobins are necessary for self-assembly at the interface and for adsorption to solid surfaces. AfRodA helps Aspergillus fumigatus to evade recognition by the host immune system. RodA-like hydrophobins recruit cutinases to promote the hydrolysis of aliphatic polyesters. This mechanism appears to be conserved in Aspergillus and other filamentous fungi, and may be beneficial for their growth. Aspergilli produce various small secreted proteins (SSPs) including hydrophobins, hydrophobic surface–binding proteins, and effector proteins. Aspergilli may use a wide variety of SSPs to decompose solid polymers.
AB - Hydrophobins are small amphipathic proteins conserved in filamentous fungi. In this review, the properties and functions of Aspergillus hydrophobins are comprehensively discussed on the basis of recent findings. Multiple Aspergillus hydrophobins have been identified and categorized in conventional class I and two non-conventional classes. Some Aspergillus hydrophobins can be purified in a water phase without organic solvents. Class I hydrophobins of Aspergilli self-assemble to form amphipathic membranes. At the air–liquid interface, RolA of Aspergillus oryzae self-assembles via four stages, and its self-assembled films consist of two layers, a rodlet membrane facing air and rod-like structures facing liquid. The self-assembly depends mainly on hydrophobin conformation and solution pH. Cys4–Cys5 and Cys7–Cys8 loops, disulfide bonds, and conserved Cys residues of RodA-like hydrophobins are necessary for self-assembly at the interface and for adsorption to solid surfaces. AfRodA helps Aspergillus fumigatus to evade recognition by the host immune system. RodA-like hydrophobins recruit cutinases to promote the hydrolysis of aliphatic polyesters. This mechanism appears to be conserved in Aspergillus and other filamentous fungi, and may be beneficial for their growth. Aspergilli produce various small secreted proteins (SSPs) including hydrophobins, hydrophobic surface–binding proteins, and effector proteins. Aspergilli may use a wide variety of SSPs to decompose solid polymers.
KW - Aspergillus
KW - biopolymer degradation
KW - hydrophobin
KW - self-assembly
KW - small secreted protein
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U2 - 10.3390/microorganisms10081498
DO - 10.3390/microorganisms10081498
M3 - Review article
AN - SCOPUS:85137328770
SN - 2076-2607
VL - 10
JO - Microorganisms
JF - Microorganisms
IS - 8
M1 - 1498
ER -