Streptomyces produce a diphtheria toxin-like exotoxin that targets insects
Year: 2026
Type: article
Abstract: Streptomyces and insects engage in complex interactions shaped by millions of years of evolution. While many beneficial relationships are well recognized, it remains unknown whether Streptomyces produce virulence factors targeting insects specifically. Here, through bioinformatic analysis, we identified diphtheria toxin (DT) homologues, which we named Streptomyces antiquus insecticidal proteins (SAIP), within a monophyletic lineage of Streptomyces that emerged more than 100 million years ago. SAIP is cytotoxic to insect cells and lethal to Drosophila melanogaster, suppressing neuronal activity and immune responses in vivo. Structural and functional studies validated that SAIP is homologous to DT and acts by ADP ribosylation of eukaryotic elongation factor 2. CRISPR-Cas9 screening identified the insect protein Flower as the SAIP receptor across a range of insects. Toxigenic Streptomyces can consume dead insects and produce bioactive secondary metabolites while growing on insect carcasses. These findings establish an insecticidal toxin in Streptomyces and demonstrate that Streptomyces have evolved highly specific virulence factors against insects.
Source: Nature Microbiology
Institutions: Boston Children's Hospital, Harvard University, Chinese Academy of Sciences, Institute of Zoology, Oklahoma State University, University of Wisconsin–Madison, Howard Hughes Medical Institute, Stockholm University, Yale University, University of California, Davis, McMaster University, University of Toronto, University of Waterloo
Language: English
Subfield: Pharmacology
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $12,690
Awards: G4216773172, G4444822939, Genetic and Molecular Analysis of Olfaction, G8010121707, Intellectual and Developmental Disablities Research Center, Analysis of Chemosensory Receptor Genes, Integrated Epithelial and Muscosal Biology, Taste perception of host cues in the invasive disease vector mosquito Aedes albopictus, Targeted Delivery of Therapeutics into Motor Neurons for Post-exposure Treatment of Botulism, Analysis of a Large Family of Candidate Taste Receptors
OpenAlex ID: W7159590270