The extracellular β-1,3-endoglucanase EngA is involved in autolysis of Aspergillus nidulans.
OBJECTIVE
To elucidate the roles of the β-1,3-endoglucanase EngA in autolysis of the filamentous fungus Aspergillus nidulans and to identify the common regulatory elements of autolytic hydrolases.


RESULTS
A β-1,3-endoglucanase was purified from carbon-starving cultures of A. nidulans. This enzyme is found to be encoded by the engA gene (locus ID: AN0472.3). Functional and gene-expression studies demonstrated that EngA is involved in the autolytic cell wall degradation resulting from carbon starvation of the fungus. Moreover, regulation of engA is found to be dependent on the FluG/BrlA asexual sporulation signalling pathway in submerged culture. The deletion of either engA or chiB (encoding an endochitinase) caused highly reduced production of hydrolases in general.


CONCLUSIONS
The β-1,3-endoglucanase EngA plays a pivotal role in fungal autolysis, and activities of both EngA and ChiB are necessary to orchestrate the expression of autolytic hydrolases. The production of cell wall-degrading enzymes was coordinately controlled in a highly sophisticated and complex manner.


CONCLUSIONS
No information was available on the autolytic glucanase(s) of the euascomycete A. nidulans. This study demonstrates that EngA is a key element in fungal autolysis, and normal activities of both EngA and ChiB are crucial for balanced production of hydrolases.
Szilágyi
M
M
Department of Microbial Biotechnology and Cell Biology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary.
Kwon
N-J
NJ
Dorogi
C
C
Pócsi
I
I
Yu
J-H
JH
Emri
T
T
D001233:Aspergillus nidulans / Q000201:enzymology* / Q000235:genetics; D001329:Autolysis / Q000201:enzymology* / Q000235:genetics; D002480:Cellulase / Q000235:genetics / Q000378:metabolism*; D002688:Chitinases / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D006867:Hydrolases / Q000378:metabolism; D009154:Mutation
D006867:Hydrolases; D002688:Chitinases; D002480:Cellulase