identifier: traitmech:000086 label: chemotaxis definition: A behavioral physiology in which cells bias their movement toward attractants or away from repellents by modulating flagellar motor switching in response to chemical gradients. definition_source: DOI:10.1038/nrm1524 trait_category: PHYSIOLOGY term_kind: CLASS mapping_status: REVIEWED parent_traits: - METPO:1000059 synonyms: - synonym_text: chemotactic synonym_type: RELATED_SYNONYM source: DOI:10.1038/nrm1524 evidence: - reference: DOI:10.1038/nrm1524 notes: Wadhams & Armitage review bacterial chemotaxis as gradient-guided movement controlled by a histidine-aspartate phosphorelay. - reference: DOI:10.1038/nrmicro2505 notes: Porter, Wadhams & Armitage review signal processing in complex chemotaxis pathways. canonical_examples: - taxon_id: NCBITaxon:562 taxon_label: Escherichia coli note: "Paradigm of bacterial chemotaxis (flagellar run-and-tumble; Che two-component signalling)." reference: PMID:15573139 causal_graphs: - graph_id: chemotaxis_gradient_response title: Gradient-guided chemotactic movement description: Evidence-backed causal sketch linking chemical gradients to biased motility via flagellar motor control. nodes: - node_id: chemotaxis_trait label: chemotaxis node_type: TRAIT grounding: traitmech:000086 description: Biased movement along chemical gradients. - node_id: chemical_gradient label: chemical gradient node_type: ENVIRONMENTAL_FACTOR description: Spatial gradient of attractant or repellent. - node_id: chemotaxis_process label: chemotaxis node_type: BIOLOGICAL_PROCESS grounding: GO:0006935 description: Signal transduction biasing motor switching. - node_id: chemoreceptor_mcp label: chemoreceptor (MCP) node_type: GENE_OR_PROTEIN description: Methyl-accepting chemotaxis protein that binds attractant/repellent ligands. - node_id: chea_kinase label: CheA histidine kinase node_type: GENE_OR_PROTEIN description: Histidine autokinase whose activity is modulated by chemoreceptors. grounding: UniProtKB:G0HQV3 - node_id: chea_autophosphorylation label: CheA autophosphorylation node_type: MOLECULAR_FUNCTION description: Autophosphorylation activity of the CheA histidine kinase. - node_id: chey label: CheY response regulator node_type: GENE_OR_PROTEIN description: Response regulator that, when phosphorylated, controls flagellar motor switching. grounding: UniProtKB:A0A2X5A7X5 - node_id: cheb label: CheB methylesterase node_type: GENE_OR_PROTEIN description: Phospho-regulated methylesterase that demethylates chemoreceptors during adaptation. grounding: UniProtKB:A0A100WWV3 - node_id: cher label: CheR methyltransferase node_type: GENE_OR_PROTEIN description: Methyltransferase that methylates chemoreceptors during adaptation. - node_id: chez label: CheZ phosphatase node_type: GENE_OR_PROTEIN description: Phosphatase that dephosphorylates CheY-P to reset signaling. - node_id: chew label: CheW coupling protein node_type: GENE_OR_PROTEIN description: Adaptor/scaffold coupling CheA to chemoreceptors in the core signaling unit. - node_id: cw_flagellar_rotation label: clockwise flagellar rotation node_type: BIOLOGICAL_PROCESS description: Clockwise flagellar motor rotation that promotes tumbling. edges: - subject: chemical_gradient predicate: causes object: chemotaxis_process description: A chemical gradient drives the chemotaxis signaling response. evidence: - reference: DOI:10.1038/nrm1524 notes: Wadhams & Armitage review gradient-guided chemotaxis signaling. predicate_id: biolink:causes - subject: chemotaxis_process predicate: enables object: chemotaxis_trait description: The chemotaxis signaling process realizes the trait. evidence: - reference: DOI:10.1038/nrmicro2505 notes: Porter et al. review chemotaxis signal processing. predicate_id: RO:0002327 - subject: chemoreceptor_mcp predicate: modulates object: chea_autophosphorylation description: Effector binding to chemoreceptors modulates CheA autophosphorylation activity. evidence: - reference: DOI:10.1146/annurev-micro-032421-110850 notes: Upon effector binding to the receptor, the autophosphorylation activity of CheA is modulated by chemoreceptors. predicate_id: RO:0002211 - subject: chea_kinase predicate: phosphorylates object: chey description: Phosphorylated CheA transfers phosphoryl groups to the response regulator CheY. evidence: - reference: DOI:10.1146/annurev-micro-032421-110850 notes: When CheA is phosphorylated, it can activate its response regulators CheB and CheY via phosphoryl transfer. - subject: chea_kinase predicate: phosphorylates object: cheb description: Phosphorylated CheA transfers phosphoryl groups to the methylesterase CheB. evidence: - reference: DOI:10.1146/annurev-micro-032421-110850 notes: When CheA is phosphorylated, it can activate its response regulators CheB and CheY via phosphoryl transfer. - subject: chey predicate: induces object: cw_flagellar_rotation description: Phosphorylated CheY interacts with the flagellar motor to induce clockwise rotation. evidence: - reference: DOI:10.1146/annurev-micro-032421-110850 notes: CheY-P interacts with the flagella to induce clockwise rotation. - subject: chez predicate: dephosphorylates object: chey description: CheZ phosphatase dephosphorylates CheY-P to maintain a stable signaling pool. evidence: - reference: DOI:10.1146/annurev-micro-032421-110850 notes: The phosphatase CheZ dephosphorylates CheY to ensure a stable pool of CheY is available. - subject: cher predicate: methylates object: chemoreceptor_mcp description: CheR methylates chemoreceptors as part of the reversible adaptation system. evidence: - reference: DOI:10.1146/annurev-micro-032421-110850 notes: CheB, along with CheR, constitutes an adaptation system that reversibly methylates receptors. - subject: cheb predicate: demethylates object: chemoreceptor_mcp description: CheB demethylates chemoreceptors as part of the reversible adaptation system. evidence: - reference: DOI:10.1146/annurev-micro-032421-110850 notes: CheB, along with CheR, constitutes an adaptation system that reversibly methylates/demethylates receptors. - subject: chew predicate: scaffolds object: chea_kinase description: CheW couples and scaffolds CheA with chemoreceptors in the core signaling unit baseplate. evidence: - reference: DOI:10.1146/annurev-micro-032421-110850 notes: The coupling protein CheW secures CheA; the baseplate consists of the chemoreceptor PIR, CheA, and CheW. curation_history: - timestamp: '2026-06-04T00:00:00Z' curator: claude action: PROPOSED_FROM_RESEARCH changes: Proposed candidate PHYSIOLOGY trait (chemotaxis), a behavioral response; distinct from the morphological motility apparatus. llm_assisted: true - timestamp: '2026-06-08T13:00:00Z' curator: claude action: CURATED_CAUSAL_GRAPH changes: Added evidence-backed causal graph (gradient-guided chemotaxis) with GO node grounding and biolink/RO predicate groundings; promoted PROPOSED to REVIEWED. llm_assisted: true - timestamp: '2026-06-23T00:00:00Z' curator: claude action: ENRICH_CAUSAL_GRAPH changes: Added 8 evidence-backed generic edges (9 new nodes) from the deep-research report. llm_assisted: true - timestamp: '2026-06-24T17:21:14Z' curator: claude action: GROUND_CAUSAL_PREDICATES changes: Grounded 1 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv (RO:0002211×1). llm_assisted: true - timestamp: '2026-06-26T07:15:20Z' curator: claude action: GROUND_CAUSAL_NODES changes: Grounded 3 causal-node grounding field(s) via mappings/node_grounding.tsv (UniProtKB:G0HQV3×1, UniProtKB:A0A2X5A7X5×1, UniProtKB:A0A100WWV3×1). llm_assisted: true