chitin biosynthesis
gomodel:YeastPathways_PWY3O-15
Saccharomyces cerevisiae S288C chitin biosynthesis route in which CHS1, CHS2, and CHS3 chitin synthase activities convert UDP-N-acetyl-alpha-D-glucosamine to chitin and UDP.
- Pathway type
- cell wall biosynthesis
- Organism scope
Pathway network
15 nodes · 29 asserted directed edges
Arrows show recorded subject → object relationships, not necessarily metabolic flow. Select a node for details or an arrow for evidence. Scroll, zoom or find a node to explore.
- Reaction / activity
- Chemical / cofactor
- Protein / complex
- Other participant
- Cell / process context
- Solid arrow: mechanistic relation
- Dashed arrow: membership, location or cofactor relation
Components and activities
| Node | Kind or role | Source direction |
|---|---|---|
Saccharomyces cerevisiae S288CNCBITaxon:559292 | taxon | |
chitinCHEBI:17029 | participant | |
CHS3 ScerSGD:S000000227 | protein | |
CHS1 ScerSGD:S000005136 | protein | |
cytosolGO:0005829 | cellular component | |
UDP(3-)CHEBI:58223 | small molecule | |
chitin biosynthetic processGO:0006031 | biological process | |
UDP-N-acetyl-alpha-D-glucosamine(2-)CHEBI:57705 | small molecule | |
CHS2 ScerSGD:S000000242 | protein | |
plasma membraneGO:0005886 | cellular component | |
cellular bud neckGO:0005935 | cellular component | |
cytoplasmic vesicle membraneGO:0030659 | cellular component | |
membraneGO:0016020 | cellular component | |
UDP-N-acetyl-α-D-glucosamine + [1,4-(N-acetyl-β-D-glucosaminyl)]n -> UDP + [1,4-(N-acetyl-β-D-glucosaminyl)](n+1)gomodel:CHITIN-SYNTHASE-RXN | molecular activity | |
chitin synthase activitygomodel:YeastPathways_PWY3O-15/6a6bcaed00000871 | molecular activity | |
chitin synthase activitygomodel:YeastPathways_PWY3O-15/6a6bcaed00000891 | molecular activity |
Mechanistic edges
| Subject | Predicate and description | Object | Evidence |
|---|---|---|---|
chitin synthase activitygomodel:YeastPathways_PWY3O-15/6a6bcaed00000871 | has_output | chitinCHEBI:17029 |
|
UDP-N-acetyl-α-D-glucosamine + [1,4-(N-acetyl-β-D-glucosaminyl)]n -> UDP + [1,4-(N-acetyl-β-D-glucosaminyl)](n+1)gomodel:CHITIN-SYNTHASE-RXN | provides_input_for | chitin synthase activitygomodel:YeastPathways_PWY3O-15/6a6bcaed00000871 |
|
CHS3 ScerSGD:S000000227 | enables | chitin synthase activitygomodel:YeastPathways_PWY3O-15/6a6bcaed00000891 |
|
chitin synthase activitygomodel:YeastPathways_PWY3O-15/6a6bcaed00000891 | has_output | chitinCHEBI:17029 |
|
CHS1 ScerSGD:S000005136 | enables | UDP-N-acetyl-α-D-glucosamine + [1,4-(N-acetyl-β-D-glucosaminyl)]n -> UDP + [1,4-(N-acetyl-β-D-glucosaminyl)](n+1)gomodel:CHITIN-SYNTHASE-RXN |
|
chitin synthase activitygomodel:YeastPathways_PWY3O-15/6a6bcaed00000871 | provides_input_for | UDP-N-acetyl-α-D-glucosamine + [1,4-(N-acetyl-β-D-glucosaminyl)]n -> UDP + [1,4-(N-acetyl-β-D-glucosaminyl)](n+1)gomodel:CHITIN-SYNTHASE-RXN |
|
UDP-N-acetyl-α-D-glucosamine + [1,4-(N-acetyl-β-D-glucosaminyl)]n -> UDP + [1,4-(N-acetyl-β-D-glucosaminyl)](n+1)gomodel:CHITIN-SYNTHASE-RXN | has_output | UDP(3-)CHEBI:58223 |
|
chitin synthase activitygomodel:YeastPathways_PWY3O-15/6a6bcaed00000871 | provides_input_for | chitin synthase activitygomodel:YeastPathways_PWY3O-15/6a6bcaed00000891 |
|
chitin synthase activitygomodel:YeastPathways_PWY3O-15/6a6bcaed00000891 | part_of | chitin biosynthetic processGO:0006031 |
|
chitin synthase activitygomodel:YeastPathways_PWY3O-15/6a6bcaed00000871 | has_input | chitinCHEBI:17029 |
|
UDP-N-acetyl-α-D-glucosamine + [1,4-(N-acetyl-β-D-glucosaminyl)]n -> UDP + [1,4-(N-acetyl-β-D-glucosaminyl)](n+1)gomodel:CHITIN-SYNTHASE-RXN | has_output | chitinCHEBI:17029 |
|
UDP-N-acetyl-α-D-glucosamine + [1,4-(N-acetyl-β-D-glucosaminyl)]n -> UDP + [1,4-(N-acetyl-β-D-glucosaminyl)](n+1)gomodel:CHITIN-SYNTHASE-RXN | has_input | UDP-N-acetyl-alpha-D-glucosamine(2-)CHEBI:57705 |
|
chitin synthase activitygomodel:YeastPathways_PWY3O-15/6a6bcaed00000891 | has_output | UDP(3-)CHEBI:58223 |
|
chitin synthase activitygomodel:YeastPathways_PWY3O-15/6a6bcaed00000891 | has_input | chitinCHEBI:17029 |
|
UDP-N-acetyl-α-D-glucosamine + [1,4-(N-acetyl-β-D-glucosaminyl)]n -> UDP + [1,4-(N-acetyl-β-D-glucosaminyl)](n+1)gomodel:CHITIN-SYNTHASE-RXN | provides_input_for | chitin synthase activitygomodel:YeastPathways_PWY3O-15/6a6bcaed00000891 |
|
chitin synthase activitygomodel:YeastPathways_PWY3O-15/6a6bcaed00000891 | provides_input_for | UDP-N-acetyl-α-D-glucosamine + [1,4-(N-acetyl-β-D-glucosaminyl)]n -> UDP + [1,4-(N-acetyl-β-D-glucosaminyl)](n+1)gomodel:CHITIN-SYNTHASE-RXN |
|
chitin synthase activitygomodel:YeastPathways_PWY3O-15/6a6bcaed00000871 | has_input | UDP-N-acetyl-alpha-D-glucosamine(2-)CHEBI:57705 |
|
chitin synthase activitygomodel:YeastPathways_PWY3O-15/6a6bcaed00000871 | has_output | UDP(3-)CHEBI:58223 |
|
chitin synthase activitygomodel:YeastPathways_PWY3O-15/6a6bcaed00000871 | part_of | chitin biosynthetic processGO:0006031 |
|
UDP-N-acetyl-α-D-glucosamine + [1,4-(N-acetyl-β-D-glucosaminyl)]n -> UDP + [1,4-(N-acetyl-β-D-glucosaminyl)](n+1)gomodel:CHITIN-SYNTHASE-RXN | part_of | chitin biosynthetic processGO:0006031 |
|
UDP-N-acetyl-α-D-glucosamine + [1,4-(N-acetyl-β-D-glucosaminyl)]n -> UDP + [1,4-(N-acetyl-β-D-glucosaminyl)](n+1)gomodel:CHITIN-SYNTHASE-RXN | has_input | chitinCHEBI:17029 |
|
chitin synthase activitygomodel:YeastPathways_PWY3O-15/6a6bcaed00000891 | provides_input_for | chitin synthase activitygomodel:YeastPathways_PWY3O-15/6a6bcaed00000871 |
|
chitin synthase activitygomodel:YeastPathways_PWY3O-15/6a6bcaed00000891 | has_input | UDP-N-acetyl-alpha-D-glucosamine(2-)CHEBI:57705 |
|
CHS2 ScerSGD:S000000242 | enables | chitin synthase activitygomodel:YeastPathways_PWY3O-15/6a6bcaed00000871 |
|
CHS3 ScerSGD:S000000227 | located_in Physical protein location from reviewed UniProt. ECO:0000269 (PubMed:12928491); ECO:0000269 (PubMed:17519287); ECO:0000269 (PubMed:28346351) Topology: Multi-pass membrane protein. Source qualification: Localizes to a ring on the surface of cells about to undergo bud emergence and in the mother-bud neck of small-budded cells (PubMed:8909536). Delocalized throughout the plasma membrane during heat shock (PubMed:12928491). Also localizes to intracellular membrane-bound particles called chitosomes, proposed to act as a reservoir for regulated transport of chitin synthase enzymes to the division septum (PubMed:12928491, PubMed:8970154) | plasma membraneGO:0005886 |
|
CHS3 ScerSGD:S000000227 | located_in Physical protein location from reviewed UniProt. ECO:0000269 (PubMed:16818716); ECO:0000269 (PubMed:28346351); ECO:0000269 (PubMed:8909536) Source qualification: Localizes to a ring on the surface of cells about to undergo bud emergence and in the mother-bud neck of small-budded cells (PubMed:8909536). Delocalized throughout the plasma membrane during heat shock (PubMed:12928491). Also localizes to intracellular membrane-bound particles called chitosomes, proposed to act as a reservoir for regulated transport of chitin synthase enzymes to the division septum (PubMed:12928491, PubMed:8970154) | cellular bud neckGO:0005935 |
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CHS3 ScerSGD:S000000227 | located_in Physical protein location from reviewed UniProt. ECO:0000269 (PubMed:12928491); ECO:0000269 (PubMed:28346351); ECO:0000269 (PubMed:8970154) Topology: Multi-pass membrane protein. Source qualification: Localizes to a ring on the surface of cells about to undergo bud emergence and in the mother-bud neck of small-budded cells (PubMed:8909536). Delocalized throughout the plasma membrane during heat shock (PubMed:12928491). Also localizes to intracellular membrane-bound particles called chitosomes, proposed to act as a reservoir for regulated transport of chitin synthase enzymes to the division septum (PubMed:12928491, PubMed:8970154) | cytoplasmic vesicle membraneGO:0030659 |
|
CHS1 ScerSGD:S000005136 | located_in Physical protein location from reviewed UniProt. ECO:0000305 (PubMed:2523889) Topology: Multi-pass membrane protein. | plasma membraneGO:0005886 |
|
CHS2 ScerSGD:S000000242 | located_in Physical protein location from reviewed UniProt. ECO:0000305 Topology: Multi-pass membrane protein. | membraneGO:0016020 |
|
References
gomodel:YeastPathways_PWY3O-15SGD GO-CAM chitin biosynthesis - imported from: Saccharomyces Genome Database (source version: Pinned Noctua JSON archive; model date 2026-08-05; member ./YeastPathways_PWY3O-15.json)UniProtKB:P29465Reviewed UniProtKB P29465 location annotations (source version: UniProt release 2026_03)UniProtKB:P08004Reviewed UniProtKB P08004 location annotations (source version: UniProt release 2026_03)UniProtKB:P14180Reviewed UniProtKB P14180 location annotations (source version: UniProt release 2026_03)
Curation history
- Codex; review-causal-graph; Reviewed every native GO-CAM fact; preserved precise input/output, causal, location, membership and complex-part relations with traceable structured source evidence. Kept distinct generic physical instances and recorded source-scope exclusions in the cohort review ledger.
- Codex
- EDIT — Audit causal activity compartments and preserve scoped protein location evidence
Reviewed all 3 activity location assignments and 3 mapped physical proteins against reviewed S288C UniProt release2026_03 location/function/caution batch SHA256 95f72dcc644358c480e0e59f996cf88533558b5fa4256460a030e0a1eaf9678d. Added 5 independently supported location edges and quarantined 3 generic cytosol source assertions. Mapped physical protein locations via exact SGD cross-references; retained source ECO grades, molecular form and conditional notes. Physical protein location alone never generates activity location. Explicitly inspected functional assertions support bounded activity projections. Every original activity location and exclusion is recorded in reports/causal_graph_review/gocam-location-review.json. No independent location annotation is treated as an evidence gap, not a negative result. Cytoplasm is not narrowed to cytosol. Microsome fractions are not projected as in-vivo organelles. Semantic validation passed all85 records;4 independent source-role acceptance tests passed.
- EDIT — Audit causal activity compartments and preserve scoped protein location evidence