Dissecting out the molecular mechanism of insecticidal activity of ostreolysin A6/pleurotolysin B complexes on western corn rootworm

Milijaš Jotić, Matej (author), Panevska, Anastasija (author), Iacovache, Ioan (author), Kostanjšek, Rok (author), Mravinec, Martina (author), Skočaj, Matej (author), Zuber, Benoît (author), Pavšič, Ana (author), Razinger, Jaka (author), Modic, Špela (author), Trenti, Francesco (author), Guella, Graziano (author), Sepčić, Kristina (author)

Ostreolysin A6 (OlyA6) is a protein produced by the oyster mushroom (Pleurotus ostreatus). It binds to membrane sphingomyelin/cholesterol domains, and together with its protein partner, pleurotolysin B (PlyB), it forms 13-meric transmembrane pore complexes. Further, OlyA6 binds 1000 times more strongly to the insect-specific membrane sphingolipid, ceramide phosphoethanolamine (CPE). In concert with PlyB, OlyA6 has potent and selective insecticidal activity against the western corn rootworm. We analysed the histological alterations of the midgut wall columnar epithelium of western corn rootworm larvae fed with OlyA6/PlyB, which showed vacuolisation of the cell cytoplasm, swelling of the apical cell surface into the gut lumen, and delamination of the basal lamina underlying the epithelium. Additionally, cryo-electron microscopy was used to explore the membrane interactions of the OlyA6/PlyB complex using lipid vesicles composed of artificial lipids containing CPE, and western corn rootworm brush border membrane vesicles. Multimeric transmembrane pores were formed in both vesicle preparations, similar to those described for sphingomyelin/cholesterol membranes. These results strongly suggest that the molecular mechanism of insecticidal action of OlyA6/PlyB arises from specific interactions of OlyA6 with CPE, and the consequent formation of transmembrane pores in the insect midgut.

• Language: English
• Keywords: aegerolysin, bioinsecticide, MACPF-protein, oyster mushroom, pore-forming protein, western corn rootworm
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Publication status: Published
• Publication version: Version of Record
• Year: 2021
• Number of pages: 16 str.
• Numbering: Vol. 13, iss. 7, art. 455
• PID: 20.500.12556/RUL-135717
• UDC: 577
• ISSN on article: 2072-6651
• DOI: 10.3390/toxins13070455
• COBISS.SI-ID: 68691203
• Publication date in RUL: 29.03.2022

Record is a part of a journal

• Title: Toxins
• Shortened title: Toxins
• Publisher: MDPI
• ISSN: 2072-6651
• COBISS.SI-ID: 517594649

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.
• Licensing start date: 01.07.2021

Secondary language

• Language: Slovenian
• Keywords: egerolizin, bioinsekticid, protein z domeno MACPF, bukov ostrigar, porotvorni protein, koruzni hrošč