High structural diversity of aeruginosins in bloom-forming cyanobacteria of the genus Planktothrix as a consequence of multiple recombination events.

Entfellner, Elisabeth; Baumann, Kathrin B.L.; Edwards, Christine; Kurmayer, Rainer

Abstract

Many compounds produced by cyanobacteria act as serine protease inhibitors, such as the tetrapeptides aeruginosins (Aer), which are found widely distributed. The structural diversity of Aer is intriguingly high. However, the genetic basis of this remains elusive. In this study, we explored the genetic basis of Aer synthesis among the filamentous cyanobacteria Planktothrix spp. In total, 124 strains, isolated from diverse freshwater waterbodies, have been compared regarding variability within Aer biosynthesis genes and the consequences for structural diversity. The high structural variability could be explained by various recombination processes affecting Aer synthesis, above all, the acquisition of accessory enzymes involved in post synthesis modification of the Aer peptide (e.g., halogenases, glycosyltransferases, sulfotransferases) as well as a large-range recombination of Aer biosynthesis genes, probably transferred from the bloom-forming cyanobacterium Microcystis. The Aer structural composition differed between evolutionary Planktothrix lineages, adapted to either shallow or deep waterbodies of the temperate climatic zone. Thus, for the first time among bloom-forming cyanobacteria, chemical diversification of a peptide family related to eco-evolutionary diversification has been described. It is concluded that various Aer peptides resulting from the recombination event act in chemical defense, possibly as a replacement for microcystins.

Citation

ENTFELLNER, E., BAUMANN, K.B.L., EDWARDS, C. and KURMAYER, R. 2023. High structural diversity of aeruginosins in bloom-forming cyanobacteria of the genus Planktothrix as a consequence of multiple recombination events. Marine drugs [online], 21(12), article number 638. Available from: https://doi.org/10.3390/md21120638

• Journal Article Type: Article
• Acceptance Date: Dec 11, 2023
• Online Publication Date: Dec 13, 2023
• Publication Date: Dec 31, 2023
• Deposit Date: Jan 11, 2024
• Publicly Available Date: Jan 11, 2024
• Journal: Marine drugs
• Electronic ISSN: 1660-3397
• Publisher: MDPI
• Peer Reviewed: Peer Reviewed
• Volume: 21
• Issue: 12
• Article Number: 638
• DOI: https://doi.org/10.3390/md21120638
• Keywords: Horizontal gene transfer; Chemical diversification; Freshwater ecotypes; Shallow waterbodies; Deep waterbodies
• Public URL: https://rgu-repository.worktribe.com/output/2197367
• Related Public URLs: https://rgu-repository.worktribe.com/output/2204782 (Supplementary material associated with this output)