Ageritin from Pioppino Mushroom: The Prototype of Ribotoxin-Like Proteins, a Novel Family of Specific Ribonucleases in Edible Mushrooms

Abstract

Ageritin is a specific ribonuclease, extracted from the edible mushroom Cyclocybe aegerita (synonym Agrocybe aegerita), which cleaves a single phosphodiester bond located within the universally conserved alpha-sarcin loop (SRL) of 23–28S rRNAs. This cleavage leads to the inhibition of protein biosynthesis, followed by cellular death through apoptosis. The structural and enzymatic properties show that Ageritin is the prototype of a novel specific ribonucleases family named ‘ribotoxin-like proteins’, recently found in fruiting bodies of other edible basidiomycetes mushrooms (e.g., Ostreatin from Pleurotus ostreatus, Edulitins from Boletus edulis, and Gambositin from Calocybe gambosa). Although the putative role of this toxin, present in high amount in fruiting body (>2.5 mg per 100 g) of C. aegerita, is unknown, its antifungal and insecticidal action strongly support a role in defense mechanisms. Thus, in this review, we focus on structural, biological, antipathogenic, and enzymatic characteristics of this ribotoxin-like protein. We also highlight its biological relevance and potential biotechnological applications in agriculture as a bio-pesticide and in biomedicine as a therapeutic and diagnostic agent.

Lessons on fruiting body morphogenesis from genomes and transcriptomes of Agaricomycetes

“…Once released, they interact with the digestive tract of the fungivore. Characterized classes of protein toxins from Agaricomycete fruiting bodies include lectins (Goldstein and Winter 2007;Bleuler-MartÍnez et al 2011;A et al 2013), protease inhibitors Sabotič et al 2019), pore-forming toxins (PFTs) (Anderluh and Maček 2003;JM et al 2010;Panevska et al 2020), ribotoxins (Tayyrov et al 2019;Ragucci et al 2021) and biotin-binding proteins (Y et al 2009; S et al 2012a).…”

Trends and Applications of Omics Technologies to Functional Characterisation of Enzymes and Protein Metabolites Produced by Fungi

“…They show more similarity to members of the ribonuclease T1 family, however. Ragucci et al [ 63 ] recently reviewed Ageritin, focusing on its structural, biological, antipathogenic, and enzymatic characteristics. The authors also discussed some of the possible biotechnological applications of Ageritin, including its use as an immunotoxin and pest control agent, which could be achieved through gene transfer in plant cells.…”

The Edible Gray Oyster Fungi Pleurotus ostreatus (Jacq. ex Fr.) P. Kumm a Potent Waste Consumer, a Biofriendly Species with Antioxidant Activity Depending on the Growth Substrate

“…As a member of basidiomycetes group, it brings to light the presence of ribotoxin—like protein (Ostreatin), a novel specific ribonucleases family. Ostrein could contribute to assigning potential biotechnological applications in agriculture (crops protection towards pathogens or pests) and in medicine (cytotoxic effects) [ 27 ].…”