identifier: traitmech:000330 label: Dionysus system definition: A phage defense system in which an organism possesses a three-gene Dionysus locus encoding DinA, DinB, and DinC components that can block jumbo-phage infection. definition_source: DOI:10.1101/2025.09.30.679545 trait_category: GENOMICS term_kind: CLASS mapping_status: PROPOSED parent_traits: - traitmech:000209 synonyms: - synonym_text: Dionysus synonym_type: EXACT_SYNONYM source: DOI:10.1101/2025.09.30.679545 evidence: - reference: DOI:10.1101/2025.09.30.679545 snippet: 'From over 500 candidate defense systems, we selected nine for experimental testing and validated three: Dionysus, a TerB-encoding system that disrupts early phage infection vesicle formation by Jumbo phages; Ophion, a Radical SAM-containing system that prevents the formation of the Jumbo phage nucleus; and Ambrosia, a tightly regulated RM-like system.' notes: Keesman et al. named Dionysus among three modular phage-defense candidates validated experimentally from an initial pool of more than 500 candidates. - reference: DOI:10.1101/2025.09.30.679545 snippet: 'Dionysus is named after the god associated with winemaking and the celebration of life. This defense system consists of three genes encoding: DinA, featuring a merozoite adhesive erythrocyte binding protein (MAEBL) and a transmembrane (TM) domain; DinB, a TerB-like protein; and DinC, a pore-forming toxin (PFT) with four TM domains' notes: Keesman et al. support Dionysus as a three-gene defense system encoding DinA, DinB, and DinC components. - reference: DOI:10.1101/2025.09.30.679545 snippet: Both Dionysus and Ophion specifically block infection by jumbo phages, which have evolved specialized compartments to protect their DNA from DNA-targeting host defenses notes: Keesman et al. support Dionysus as a system that blocks infection by jumbo phages with early phage infection vesicles. - reference: DOI:10.1101/2025.09.30.679545 snippet: Specifically, we show that Dionysus forms pores in the EPI vesicle of the jumbo phage to disrupt the infection cycle of the phage at an early stage, similar to the mechanism described for the Juk phage defense system notes: Keesman et al. connect Dionysus to disruption of the jumbo phage early phage infection vesicle and therefore to interruption of the phage infection cycle. - reference: DOI:10.1101/2025.09.30.679545 snippet: All three proteins of Dionysus are essential for its protective capacity, as mutating a conserved amino acid within the MAEBL-like domain of DinA (H326A), and deletion of DinB or DinC, resulted in the partial (DinA H326A) or complete loss of anti-phage activity notes: Keesman et al. support all three Dionysus proteins as required for full anti-phage protection in the tested system. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md snippet: Dionysus | 10\.1101/2025\.09\.30\.679545 | Discovery of phage defense systems through component modularity networks notes: The DefenseFinder article registry maps the named Dionysus system to the Keesman et al. modular phage-defense discovery preprint; the pinned DefenseFinder HMM inventory and rules table do not list Dionysus, so this row is name-to-paper evidence rather than model-component evidence. causal_graphs: - graph_id: dionysus_locus_restricts_phage title: Dionysus loci confer bacterial phage defense description: Conservative system-level sketch linking possession of a Dionysus locus to restricted jumbo-phage propagation without asserting the direct phage trigger or protein-resolved pore-forming sequence. scope_status: NONMECHANISTIC scope_notes: The graph captures Dionysus as a named three-gene anti-jumbo-phage system while leaving its direct phage trigger, the DinA/DinB/DinC interaction sequence, the natural locus breadth, and the absence of pinned DefenseFinder HMM or rule rows unresolved. nodes: - node_id: dionysus_locus label: Dionysus locus node_type: GENETIC_ELEMENT description: A three-gene Dionysus anti-phage defense locus encoding DinA, DinB, and DinC components. - node_id: restricted_phage_propagation label: restricted phage propagation node_type: BIOLOGICAL_PROCESS description: Reduced propagation of bacteriophage in cells carrying the Dionysus system. - node_id: dionysus_system_trait label: Dionysus system node_type: TRAIT grounding: traitmech:000330 description: Possession of a genome-encoded Dionysus phage-defense system. - node_id: phage_defense_system label: phage defense system node_type: TRAIT grounding: traitmech:000209 description: Possession of one or more genome-encoded immune systems that inhibit bacteriophage infection. edges: - subject: dionysus_locus predicate: contributes to predicate_id: RO:0002326 object: restricted_phage_propagation description: The three-gene Dionysus locus restricts infection by jumbo phages. evidence: - reference: DOI:10.1101/2025.09.30.679545 snippet: Both Dionysus and Ophion specifically block infection by jumbo phages, which have evolved specialized compartments to protect their DNA from DNA-targeting host defenses notes: Keesman et al. report that Dionysus blocks infection by jumbo phages. - reference: DOI:10.1101/2025.09.30.679545 snippet: All three proteins of Dionysus are essential for its protective capacity, as mutating a conserved amino acid within the MAEBL-like domain of DinA (H326A), and deletion of DinB or DinC, resulted in the partial (DinA H326A) or complete loss of anti-phage activity notes: Keesman et al. report that DinA, DinB, and DinC perturbations reduce or abolish Dionysus anti-phage activity. - subject: restricted_phage_propagation predicate: confers predicate_id: METPO:2007700 object: dionysus_system_trait description: Dionysus-mediated phage restriction realizes the Dionysus system trait. evidence: - reference: DOI:10.1101/2025.09.30.679545 snippet: Specifically, we show that Dionysus forms pores in the EPI vesicle of the jumbo phage to disrupt the infection cycle of the phage at an early stage, similar to the mechanism described for the Juk phage defense system notes: Keesman et al. connect Dionysus activity to disruption of the jumbo-phage infection cycle at an early vesicle stage. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md snippet: Dionysus | 10\.1101/2025\.09\.30\.679545 | Discovery of phage defense systems through component modularity networks notes: The DefenseFinder article registry maps the named Dionysus system to the Keesman et al. modular phage-defense discovery preprint; the pinned DefenseFinder HMM inventory and rules table do not list Dionysus, so this row is name-to-paper evidence rather than model-component evidence. - subject: dionysus_system_trait predicate: is a predicate_id: rdfs:subClassOf object: phage_defense_system description: Dionysus system possession is a phage-defense-system trait. evidence: - reference: DOI:10.1101/2025.09.30.679545 snippet: 'From over 500 candidate defense systems, we selected nine for experimental testing and validated three: Dionysus, a TerB-encoding system that disrupts early phage infection vesicle formation by Jumbo phages; Ophion, a Radical SAM-containing system that prevents the formation of the Jumbo phage nucleus; and Ambrosia, a tightly regulated RM-like system.' notes: Keesman et al. list Dionysus among experimentally validated phage-defense systems. - reference: https://raw.githubusercontent.com/mdmparis/defense-finder-models/afb0e5a8b466be53586b13266f5d38d98c3ac268/List_system_article.md snippet: Dionysus | 10\.1101/2025\.09\.30\.679545 | Discovery of phage defense systems through component modularity networks notes: The DefenseFinder article registry maps the named Dionysus system to the Keesman et al. modular phage-defense discovery preprint; the pinned DefenseFinder HMM inventory and rules table do not list Dionysus, so this row is name-to-paper evidence rather than model-component evidence. discussions: - discussion_id: dionysus-jumbo-phage-mechanism-gap prompt: Resolve Dionysus phage triggers, EPI-vesicle pore formation, and model coverage before minting narrower Dionysus mechanism children. kind: KNOWLEDGE_GAP status: OPEN rationale: Keesman et al. support Dionysus as a three-gene anti-jumbo-phage system that disrupts the jumbo-phage EPI vesicle stage, but the direct phage trigger, exact DinA/DinB/DinC interaction sequence, natural locus breadth, and profile-to-component model are not resolved enough here to assert a narrower mechanistic child trait. attaches_to: - causal_graphs#dionysus_locus_restricts_phage posed_by: codex posed_date: '2026-09-21' curation_history: - timestamp: '2026-09-21T07:22:15Z' curator: codex action: MINTED_TRAITMECH_ID changes: Minted Dionysus system as a DOI-backed GENOMICS TraitRecord under phage defense system after an ignored-and-hidden duplicate review found no exact live TraitMech, METPO, history, or prior proposal record; the replacement placeholder is reserved in proposals/metpo_traitmech_v207. llm_assisted: true