A0A1S3BTE3 encodes a mitogen-activated protein kinase (MAPK) in Cucumis melo (muskmelon). The protein belongs to the CMGC kinase superfamily, MAP kinase subfamily, and contains a conserved protein kinase domain (residues 25-316) with a TDY dual-phosphorylation motif in its activation loop, classifying it as a Group D MAPK. MAPKs are serine/threonine kinases that function as terminal components of three-tiered phosphorylation cascades (MAPKKK-MAPKK-MAPK) and are activated by dual phosphorylation on the Thr and Tyr residues of the TXY motif by upstream MAPK kinases. In plants, MAPKs are central signal transducers that relay extracellular stimuli into intracellular responses, with established roles in biotic stress defense, abiotic stress tolerance, hormone signaling, and developmental regulation. The protein uses ATP as a phosphate donor to phosphorylate serine and threonine residues on downstream substrates (EC:2.7.11.24).
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0000165 MAPK cascade | IEA GO_REF:0000108 | ACCEPT | Summary: This annotation was inferred by logical inference from the MAP kinase activity annotation (GO:0004707). MAPKs are by definition components of MAPK cascades, functioning as the terminal kinase in the three-tiered MAPKKK-MAPKK-MAPK phosphorylation relay. The CDD domain assignment (STKc_TDY_MAPK) and membership in the MAP kinase subfamily confirm this protein is a bona fide MAPK cascade component. Reason: Participation in the MAPK cascade is an inherent property of MAP kinases and is well supported by the domain architecture and subfamily classification. Supporting Evidence: file:CUCME/A0A1S3BTE3/A0A1S3BTE3-uniprot.txt Belongs to the protein kinase superfamily. CMGC Ser/Thr protein kinase family. MAP kinase subfamily. |
| GO:0000166 nucleotide binding | IEA GO_REF:0000104 | MARK AS OVER ANNOTATED | Summary: Nucleotide binding is technically correct for this kinase, as it binds ATP, but this is a very broad parent term. The more specific ATP binding term (GO:0005524) is already annotated and provides far more biological specificity. Kinases bind ATP specifically, not nucleotides in general. Reason: The term is redundant with the more specific GO:0005524 (ATP binding) annotation and adds no biological information beyond what that term already conveys. Supporting Evidence: file:CUCME/A0A1S3BTE3/A0A1S3BTE3-uniprot.txt ATP-binding |
| GO:0004707 MAP kinase activity | IEA GO_REF:0000120 | ACCEPT | Summary: MAP kinase activity is the core molecular function of this protein. The UniProt entry assigns EC:2.7.11.24 (MAP kinase), and the protein is classified in the MAP kinase subfamily with the characteristic CDD domain STKc_TDY_MAPK. The catalytic activity annotations in UniProt describe phosphorylation of both serine and threonine residues on protein substrates using ATP, consistent with the dual-specificity serine/threonine kinase activity that defines MAPKs. Reason: This is the most informative and specific molecular function term for this enzyme, matching the EC number, domain architecture, and subfamily classification. Supporting Evidence: file:CUCME/A0A1S3BTE3/A0A1S3BTE3-uniprot.txt EC=2.7.11.24 file:CUCME/A0A1S3BTE3/A0A1S3BTE3-uniprot.txt Belongs to the protein kinase superfamily. CMGC Ser/Thr protein kinase family. MAP kinase subfamily. |
| GO:0005524 ATP binding | IEA GO_REF:0000120 | KEEP AS NON CORE | Summary: ATP binding is essential for kinase catalytic activity. The UniProt entry identifies a specific ATP-binding site at residue 54 within the protein kinase domain, and the protein carries the ATP-binding keyword. ATP serves as the phosphate donor in the phosphotransferase reaction catalyzed by this MAPK. Reason: ATP binding is mechanistically required for kinase function but is not the distinguishing core function of the protein. MAP kinase activity (GO:0004707) already implies ATP use. Retaining as non-core since it describes a genuine molecular property. Supporting Evidence: file:CUCME/A0A1S3BTE3/A0A1S3BTE3-uniprot.txt BINDING 54 /ligand="ATP" file:CUCME/A0A1S3BTE3/A0A1S3BTE3-uniprot.txt ATP-binding |
| GO:0007165 signal transduction | IEA GO_REF:0000117 | MARK AS OVER ANNOTATED | Summary: Signal transduction is a broad biological process term. While MAPKs are certainly signal transducers, the more specific MAPK cascade term (GO:0000165) is already annotated and provides a much more informative description of the signaling pathway this protein participates in. Signal transduction is a parent term of MAPK cascade. Reason: The term is technically correct but redundant with the more specific GO:0000165 (MAPK cascade) annotation. The broad signal transduction term adds no specificity beyond what the MAPK cascade annotation already provides. Supporting Evidence: file:CUCME/A0A1S3BTE3/A0A1S3BTE3-uniprot.txt Belongs to the protein kinase superfamily. CMGC Ser/Thr protein kinase family. MAP kinase subfamily. |
| GO:0106310 protein serine kinase activity | IEA GO_REF:0000116 | KEEP AS NON CORE | Summary: This annotation was derived from the Rhea-mapped catalytic activity for serine phosphorylation (RHEA:17989). The UniProt entry explicitly describes catalysis of L-seryl-[protein] + ATP phosphorylation. While this is correct, the MAP kinase activity term (GO:0004707) is more specific and already captures the fact that MAPKs phosphorylate serine (and threonine) residues on substrates. Reason: The serine kinase activity is a genuine molecular function of this enzyme, directly supported by the Rhea-curated catalytic reaction, but it is less informative than the MAP kinase activity term which already encompasses serine/threonine phosphorylation. Supporting Evidence: file:CUCME/A0A1S3BTE3/A0A1S3BTE3-uniprot.txt L-seryl-[protein] + ATP = O-phospho-L-seryl-[protein] + ADP |
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Download this section (compressed HTML)Q: Which specific MAPK cascade does this Group D MAPK participate in, and what upstream MAPKK activates it?
Q: What are the downstream phosphorylation substrates of this MAPK in Cucumis melo, and which stress or developmental pathways do they mediate?
Q: Is this MAPK orthologous to Arabidopsis MPK3, MPK4, or MPK6, and does it share similar roles in pathogen defense or abiotic stress signaling?
Experiment: Express and purify the recombinant protein and a candidate upstream MAPKK from melon, perform in vitro kinase assays to confirm phosphorylation of the TDY motif, and use phospho-specific antibodies to monitor activation in vivo under pathogen challenge or drought stress.
Hypothesis: This MAPK is activated by dual phosphorylation on its TDY motif by an upstream MAPKK during biotic or abiotic stress.
Type: in vitro kinase assay with phosphorylation-specific western blotting
Experiment: Generate VIGS (virus-induced gene silencing) knockdown lines in melon and assess susceptibility to fungal or bacterial pathogens compared to wild-type controls, monitoring both MAPK activation and defense gene expression.
Hypothesis: This MAPK plays a role in defense signaling against pathogens in Cucumis melo.
Type: reverse genetics with pathogen challenge assay
These computational predictions are reviewed separately from the GOA annotation set used for this review. The assessments below are from this project and do not constitute official GO annotations or endorsement by GO/UniProt. They are not included in the existing annotation review above.
View prediction review YAML · A0A1S3BTE3-protnlm-predictions-review.yaml · Review status: COMPLETE
ProtNLM2 made no predictions (GO or subcellular location) for Mitogen-activated protein kinase 15. The model returned only a protein name.
Source documents: genes/CUCME/A0A1S3BTE3/A0A1S3BTE3-uniprot.txt · genes/CUCME/A0A1S3BTE3/A0A1S3BTE3-goa.tsv
No GO/EC predictions in the reviewed source.
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