Year: 2026
Type: preprint
Abstract: Diverse bacteria produce proteinaceous polymeric coils called R-bodies (“refractile bodies”), which extend into ∼10 µm-long needles in response to environmental triggers. It has been proposed that R-bodies deliver toxins intracellularly after such bacteria are ingested by eukaryotes, but intra-host extension of R-bodies has not been directly observed and these toxins remain unidentified. We use Pseudomonas aeruginosa PA14 and Dictyostelium discoideum to show that R-bodies extend within amoebae. We also identify a novel toxin, DeaR ( de aminase a ssociated with the R -body), which contributes to predation resistance and forms a near-megadalton dodecamer with ADP deaminase activity that alters purine metabolism. Our findings elucidate the molecular basis of R-body-mediated toxicity during PA14 infection and provide a paradigm for understanding the potential of c ytotoxic e ffectors d elivered by R -bodies (CEDRs) in interkingdom interactions.
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
Funders: National Science Foundation, Memorial Sloan-Kettering Cancer Center, National Institutes of Health, Perelman School of Medicine, University of Pennsylvania, Medical School, University of Michigan, Irving Medical Center, Columbia University, National Institute of General Medical Sciences, Division of Materials Research
OpenAlex ID: W7223220652