Journal article

Publication year: 2019

Pages: e01549-19-

Journal: Applied and Environmental Microbiology

Volume number: 85

Issue number: 21

ISSN: 0099-2240

eISSN: 1098-5336

Open access status: Green

DOI Link: https://doi.org/10.1128/AEM.01549-19

Publisher: American Society for Microbiology

Abstract: 
Fungi produce various defense proteins against antagonists, including ribotoxins. These toxins cleave a single phosphodiester bond within the universally conserved sarcin-ricin loop of ribosomes and inhibit protein biosynthesis. Here, we report on the structure and function of ageritin, a previously reported ribotoxin from the edible mushroom Agrocybe aegerita. The amino acid sequence of ageritin was derived from cDNA isolated from the dikaryon A. aegerita AAE-3 and lacks, according to in silico prediction, a signal peptide for classical secretion, predicting a cytoplasmic localization of the protein. The calculated molecular weight of the protein is slightly higher than the one reported for native ageritin. The A. aegerita ageritin-encoding gene, AaeAGT1, is highly induced during fruiting, and toxicity assays with AaeAGT1 heterologously expressed in Escherichia coli showed a strong toxicity against Aedes aegypti larvae yet not against nematodes. The activity of recombinant A. aegerita ageritin toward rabbit ribosomes was confirmed in vitro. Mutagenesis studies revealed a correlation between in vivo and in vitro activities, indicating that entomotoxicity is mediated by ribonucleolytic cleavage. The strong larvicidal activity of ageritin makes this protein a promising candidate for novel biopesticide development.IMPORTANCE Our results suggest a pronounced organismal specificity of a protein toxin with a very conserved intracellular molecular target. The molecular details of the toxin-target interaction will provide important insight into the mechanism of action of protein toxins and the ribosome. This insight might be exploited to develop novel bioinsecticides.

Harvard Citation style: Tayyrov, A., Azevedo, S., Herzog, R., Vogt, E., Arzt, S., Lüthy, P., et al. (2019) Heterologous Production and Functional Characterization of Ageritin, a Novel Type of Ribotoxin Highly Expressed during Fruiting of the Edible Mushroom Agrocybe aegerita, Applied and Environmental Microbiology, 85(21), Article ARTN e01549-19. p. e01549-19. https://doi.org/10.1128/AEM.01549-19

APA Citation style: Tayyrov, A., Azevedo, S., Herzog, R., Vogt, E., Arzt, S., Lüthy, P., Müller, P., Rühl, M., Hennicke, F., & Künzler, M. (2019). Heterologous Production and Functional Characterization of Ageritin, a Novel Type of Ribotoxin Highly Expressed during Fruiting of the Edible Mushroom Agrocybe aegerita. Applied and Environmental Microbiology. 85(21), Article ARTN e01549-19, e01549-19. https://doi.org/10.1128/AEM.01549-19