identifier: traitmech:000084 label: quorum sensing definition: A cell-density-dependent regulatory physiology in which cells produce, release, and detect diffusible autoinducer signals to coordinate gene expression across a population. definition_source: DOI:10.1146/annurev.cellbio.21.012704.131001 trait_category: PHYSIOLOGY term_kind: CLASS mapping_status: REVIEWED parent_traits: - METPO:1000059 synonyms: - synonym_text: autoinduction synonym_type: RELATED_SYNONYM source: DOI:10.1146/annurev.cellbio.21.012704.131001 evidence: - reference: DOI:10.1146/annurev.cellbio.21.012704.131001 notes: Waters & Bassler review quorum sensing as autoinducer-mediated cell-to-cell communication coordinating population-wide behavior. - reference: DOI:10.1146/annurev.micro.55.1.165 notes: Miller & Bassler review quorum sensing across bacteria and its regulatory logic. canonical_examples: - taxon_id: NCBITaxon:668 taxon_label: Aliivibrio fischeri note: "Where quorum sensing was discovered (LuxI/LuxR autoinduction of bioluminescence); the founding QS model. Vibrio harveyi is a parallel model." reference: DOI:10.1128/jb.00035-24 causal_graphs: - graph_id: quorum_sensing_autoinducer title: Autoinducer-mediated quorum sensing description: Evidence-backed causal sketch linking accumulating autoinducer signals to coordinated population-wide gene expression. nodes: - node_id: quorum_sensing_trait label: quorum sensing node_type: TRAIT grounding: traitmech:000084 description: Cell-density-dependent coordinated regulation. - node_id: autoinducer label: autoinducer node_type: CHEMICAL description: Diffusible signal whose concentration tracks cell density. grounding: CHEBI:71338 - node_id: quorum_sensing_process label: quorum sensing node_type: BIOLOGICAL_PROCESS grounding: GO:0009372 description: Detection of autoinducer and population-wide response. - node_id: threshold_autoinducer_concentration label: threshold autoinducer concentration node_type: ENVIRONMENTAL_FACTOR description: Threshold accumulated autoinducer concentration (high cell density) that triggers QS activation. - node_id: signal_receptor label: cognate signal receptor node_type: GENE_OR_PROTEIN description: Cognate sensor protein/receptor that detects accumulated autoinducer and alters gene expression. - node_id: quorum_quenching_enzyme label: quorum-quenching enzyme node_type: GENE_OR_PROTEIN description: Signal-degrading/inactivating enzyme (e.g., lactonase) that interrupts quorum sensing. grounding: UniProtKB:G2JHL6 - node_id: qs_inhibitor label: quorum-sensing inhibitor node_type: CHEMICAL description: Small molecule that disrupts QS by inhibiting signal receptors or pathways. edges: - subject: autoinducer predicate: participates in object: quorum_sensing_process description: Autoinducer accumulation drives quorum sensing. evidence: - reference: DOI:10.1146/annurev.cellbio.21.012704.131001 notes: Waters & Bassler review autoinducer-mediated communication. predicate_id: biolink:participates_in - subject: quorum_sensing_process predicate: enables object: quorum_sensing_trait description: The sensing process realizes the quorum-sensing trait. evidence: - reference: DOI:10.1146/annurev.micro.55.1.165 notes: Miller & Bassler review quorum-sensing regulatory logic. predicate_id: RO:0002327 - subject: threshold_autoinducer_concentration predicate: enables detection by object: signal_receptor description: Once autoinducer reaches a threshold concentration it is detected by cognate sensor proteins, activating QS. evidence: - reference: DOI:10.3390/ijms25052655 notes: Once the concentration of secreted AI molecules has reached a threshold level, they are detected by cognate sensor proteins (generic, cross-taxa). - subject: signal_receptor predicate: positively regulates object: autoinducer description: Activated signal-receptor complex promotes autoinducer synthase transcription, forming the autoinduction positive-feedback loop. evidence: - reference: DOI:10.3390/ijms25052655 notes: AHL-LuxR complex recognises the lux box of luxI to promote luxI transcription, described as a positive feedback loop central to autoinduction. - subject: quorum_quenching_enzyme predicate: inactivates object: autoinducer description: Quorum-quenching enzymes degrade/inactivate QS autoinducer signals, interrupting quorum sensing. evidence: - reference: DOI:10.3390/ijms25052655 notes: QQ enzymes that inactivate QS signals (broad inhibitory branch). - subject: qs_inhibitor predicate: inhibits object: signal_receptor description: QS inhibitors chemically disrupt quorum sensing by inhibiting signal receptors / QS pathways. evidence: - reference: DOI:10.3390/ijms25052655 notes: QS inhibitors (QSIs) that chemically disrupt QS via inhibition of signal receptors (broad class). predicate_id: RO:0002212 curation_history: - timestamp: '2026-06-04T00:00:00Z' curator: claude action: PROPOSED_FROM_RESEARCH changes: Proposed candidate PHYSIOLOGY trait (quorum sensing) from literature research to fill the cell-cell-signaling gap. llm_assisted: true - timestamp: '2026-06-08T13:00:00Z' curator: claude action: CURATED_CAUSAL_GRAPH changes: Added evidence-backed causal graph (autoinducer quorum sensing) with GO node grounding and biolink/RO predicate groundings; promoted PROPOSED to REVIEWED. llm_assisted: true - timestamp: '2026-06-14T05:51:47Z' curator: claude action: GROUND_CAUSAL_NODES changes: Grounded 1 causal-node grounding field(s) via mappings/node_grounding.tsv (CHEBI:71338×1). llm_assisted: true - timestamp: '2026-06-23T00:00:00Z' curator: claude action: ENRICH_CAUSAL_GRAPH changes: Added 4 evidence-backed generic edges (4 new nodes) from the deep-research report. llm_assisted: true - timestamp: '2026-06-24T17:21:15Z' curator: claude action: GROUND_CAUSAL_PREDICATES changes: Grounded 1 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv (RO:0002212×1). llm_assisted: true - timestamp: '2026-06-26T07:15:20Z' curator: claude action: GROUND_CAUSAL_NODES changes: Grounded 1 causal-node grounding field(s) via mappings/node_grounding.tsv (UniProtKB:G2JHL6×1). llm_assisted: true