MPK6 (AtMPK6, At2g43790) is a TEY-motif mitogen-activated protein kinase of the CMGC/MAPK family and one of the central stress- and development-responsive MAPKs in Arabidopsis. As the terminal kinase of multiple MAP kinase cascades, MPK6 is activated by dual phosphorylation of its Thr-Glu-Tyr (TEY) activation-loop motif (Thr221/Tyr223) by upstream MAP kinase kinases (MKK2, MKK3, MKK4, MKK5, MKK6, MKK7 and MKK9), which are themselves activated by MAPKKKs such as MEKK1, YODA (YDA), ANP1 and MKKK20 downstream of cell-surface receptors including the flagellin receptor FLS2 and the ERECTA receptor-like kinase. Once activated, MPK6 phosphorylates serine/threonine residues (preferring a proline-directed S/T-P motif) on numerous substrates, including the ethylene-biosynthesis enzymes ACS2/ACS6, the transcription factors EIN3, WRKY33/WRKY34 and MYB41, the stomatal regulators SPEECHLESS (SPCH) and SCREAM/ICE1, the ethylene response factor ERF104, VQ-motif proteins, and the polarity protein BASL. Through these substrates MPK6 functions largely redundantly with the closely related MPK3 in innate immunity (PAMP-triggered responses and camalexin phytoalexin biosynthesis), abiotic-stress signaling (oxidative/ROS, ozone, osmotic, salt, cold and freezing, UV-B), hormone signaling (ethylene, jasmonate, abscisic acid), and a range of developmental processes (stomatal patterning and asymmetric cell division, inflorescence and organ architecture, ovule and pollen development, and root development with cell-division-plane control). MPK6 is predominantly cytoplasmic and nuclear, translocating to the nucleus upon activation, and is additionally recruited to the cell cortex and to cytoskeletal cell-division structures (preprophase band, phragmoplast) and the trans-Golgi network. Its activity is negatively controlled by protein phosphatases including the PP2C AP2C1 and the dual-specificity/protein-tyrosine phosphatases MKP1, MKP2 (DSPTP1B) and PTP1.
Definition: Binding of a MAP kinase to a protein substrate that it phosphorylates, typically via a docking (D-) motif on the substrate, distinct from generic protein binding.
Justification: Many of MPK6's IPI 'protein binding' annotations actually represent well-documented kinase-substrate interactions (ERF104, MYB41, VQ proteins, LIP5, ICE1, BASL, AHL13). A dedicated MF term for MAP-kinase-substrate binding would capture these informatively rather than discarding them as generic protein binding.
Parent term: protein kinase binding
Supporting Evidence:
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0035556 intracellular signal transduction | IBA GO_REF:0000033 | ACCEPT | Summary: IBA phylogenetic annotation placing MPK6 in intracellular signal transduction. Correct at the family level (MAPKs are universal intracellular signaling modules) but broad relative to MPK6's well-characterized MAPK-cascade role. Reason: Accurate and conservative; MPK6 is unambiguously an intracellular signal-transduction kinase. IBA annotations from the well-curated MAPK family are reliable. The more specific MAPK cascade term is also annotated. Supporting Evidence: PMID:12119167 Mitogen-activated protein kinase (MAPK) cascades are universal signal transduction modules in eukaryotes, including yeasts, animals and plants. |
| GO:0000165 MAPK cascade | IEA GO_REF:0000108 | ACCEPT | Summary: MPK6 is the terminal MAP kinase of numerous MAP kinase cascades (e.g. MEKK1-MKK4/MKK5-MPK3/MPK6 in immunity; YDA-MKK4/MKK5-MPK3/MPK6 in stomatal development; MKK2-MPK4/MPK6 in cold/salt; MKK9-MPK6 in senescence). A core process. Reason: Strongly supported experimentally. MPK6 functioning within MAPK cascades is a defining feature of the protein. Supporting Evidence: PMID:11875555 Here we identify a complete plant MAP kinase cascade (MEKK1, MKK4/MKK5 and MPK3/MPK6) and WRKY22/WRKY29 transcription factors that function downstream of the flagellin receptor FLS2 file:ARATH/MPK6/MPK6-deep-research-falcon.md MAPKs are terminal kinases in a conserved signaling architecture in which upstream kinases sequentially activate MAP2Ks and then MAPKs. |
| GO:0004672 protein kinase activity | IEA GO_REF:0000002 | ACCEPT | Summary: InterPro-based prediction of protein kinase activity from the conserved protein kinase domain (IPR000719). Correct but more general than the experimentally established serine/threonine MAP kinase activity. Reason: Accurate parent-level molecular function annotation. MPK6 is a bona fide protein kinase (EC 2.7.11.24); the kinase domain spans residues 63-348. More specific MF terms are also present. Supporting Evidence: PMID:10713056 AtMPK6 is phosphorylated on threonine and tyrosine residues in elicited cells |
| GO:0004707 MAP kinase activity | IEA GO_REF:0000120 | ACCEPT | Summary: MAP kinase activity (EC 2.7.11.24) is the core molecular function of MPK6, a TEY-motif MAPK activated by dual Thr221/Tyr223 phosphorylation acting as the terminal kinase of MAPK cascades. Reason: Defining core molecular function of MPK6, with extensive experimental support (also annotated IDA from PMID:10713056). Supporting Evidence: PMID:10713056 Microbial elicitors induce activation and dual phosphorylation of the Arabidopsis thaliana MAPK 6 file:ARATH/MPK6/MPK6-deep-research-falcon.md MPK6 functions as a proline-directed MAP kinase that phosphorylates downstream substrates including transcription factors, enzymes, RNA-metabolism proteins, and developmental regulators, often redundantly with MPK3. |
| GO:0005524 ATP binding | IEA GO_REF:0000002 | ACCEPT | Summary: ATP binding inferred from the kinase ATP-binding motifs (InterPro IPR017441; UniProt BINDING 69-77 and 92). Required cofactor binding for kinase catalysis. Reason: Well-supported by sequence and structure; MPK6 binds ATP at the canonical kinase pocket and the K92 invariant lysine is essential for catalysis (K92M abolishes activity). Supporting Evidence: file:ARATH/MPK6/MPK6-uniprot.txt MUTAGENESIS OF LYS-92 AND LYS-93 |
| GO:0005634 nucleus | IEA GO_REF:0000044 | ACCEPT | Summary: Nuclear localization, consistent with activation-triggered nuclear translocation of MPK6 where it phosphorylates nuclear substrates such as EIN3, SPCH, ICE1 and WRKY factors. Reason: Nuclear localization is experimentally established (also EXP from PMID:31235876) and functionally important, as MPK6 translocates to the nucleus upon phosphorylation. Supporting Evidence: PMID:15500467 activated AtMPK3 and AtMPK6 are translocated to the nucleus during the early stages of O3 treatment |
| GO:0005737 cytoplasm | IEA GO_REF:0000044 | ACCEPT | Summary: Cytoplasmic localization is the resting-state location of MPK6 (UniProt Subcellular Location Cytoplasm), from which it translocates to the nucleus upon activation. Reason: Well established (also annotated IBA via cytosol). MPK6 is predominantly cytoplasmic before activation. Supporting Evidence: PMID:15500467 activated AtMPK3 and AtMPK6 are translocated to the nucleus during the early stages of O3 treatment file:ARATH/MPK6/MPK6-deep-research-falcon.md This implies a functional distribution spanning nucleus and cytoplasm. |
| GO:0005938 cell cortex | IEA GO_REF:0000044 | KEEP AS NON CORE | Summary: Cell cortex localization, where MPK6 is recruited in a polarized manner by the BASL polarity protein during stomatal asymmetric cell division. Reason: Supported experimentally (also IDA from PMID:25843888), but a specialized context-dependent cortical localization rather than the principal site of MPK6 action. Supporting Evidence: PMID:25843888 Phosphorylated BASL functions as a scaffold and recruits the MAPKKK YODA and MPK3/6 to spatially concentrate signaling at the cortex |
| GO:0007165 signal transduction | IEA GO_REF:0000117 | ACCEPT | Summary: ARBA machine-learning annotation for signal transduction. Correct but a very general parent term. Reason: Accurate at a high level; more specific terms (MAPK cascade, intracellular signal transduction) better capture MPK6 function and are also annotated. Supporting Evidence: PMID:12119167 These protein phosphorylation cascades link extracellular stimuli to a wide range of cellular responses |
| GO:0106310 protein serine kinase activity | IEA GO_REF:0000116 | ACCEPT | Summary: Protein serine kinase activity (from Rhea RHEA:17989). MPK6 is a proline-directed Ser/Thr MAP kinase phosphorylating S/T-P motifs on substrates. Reason: Core catalytic activity supported by the curated RHEA reaction and extensive in vitro/in vivo kinase assays. Numerous EXP duplicates of this term exist. Supporting Evidence: PMID:22631074 a preference towards the sequence L/P-P/X-S-P-R/K for both kinases |
| GO:0005515 protein binding | IPI PMID:15225555 The MKK2 pathway mediates cold and salt stress signaling in ... | REMOVE | Summary: IPI interaction with MKK2 (Q9S7U9), the upstream MAP kinase kinase that directly activates MPK6 in cold/salt-stress signaling. Reason: Bare protein binding is uninformative; the MKK2-MPK6 relationship is captured functionally by the MAPK cascade and cold/salt response annotations. Supporting Evidence: PMID:15225555 MKK2 directly targets MPK4 and MPK6 |
| GO:0005515 protein binding | IPI PMID:19416906 Flg22 regulates the release of an ethylene response factor s... | REMOVE | Summary: IPI interaction with ERF104 (Q9FKG1), an ethylene response factor that is an MPK6 substrate; the MPK6-ERF104 complex is disrupted upon flg22 perception. Reason: Uninformative bare protein binding. ERF104 is an MPK6 substrate; the meaningful function is captured by kinase activity and immunity process terms. Supporting Evidence: PMID:19416906 the in vivo enzyme-substrate interaction of the Arabidopsis thaliana MAP kinase, MPK6, with an ethylene response factor (ERF104) is shown by fluorescence resonance energy transfer |
| GO:0005515 protein binding | IPI PMID:19513235 Comprehensive analysis of protein-protein interactions betwe... | REMOVE | Summary: IPI interactions with MAP kinase kinases MKK4 (O80397), MKK5 (Q8RXG3), MKK6 (Q9FJV0) and MKK2 (Q9S7U9) defining signaling modules; these upstream MKKs activate MPK6. Reason: Bare protein binding is uninformative; the functionally relevant relationship (MPK6 downstream of these MKKs) is captured by the MAPK cascade annotation. Supporting Evidence: PMID:19513235 Comprehensive analysis of protein-protein interactions between Arabidopsis MAPKs and MAPK kinases helps define potential MAPK signalling modules |
| GO:0005515 protein binding | IPI PMID:21276203 The Arabidopsis protein kinase Pto-interacting 1-4 is a comm... | REMOVE | Summary: IPI interaction with CARK3/PTI1-4 (O80719), a protein kinase that is an MPK6 substrate in oxidative-stress signaling. Reason: Uninformative bare protein binding; PTI1-4 is an MPK6 substrate captured by kinase activity. The same PMID supports protein kinase activity (IMP), which is retained. Supporting Evidence: PMID:21276203 OXI1 and PTI1-4 were substrates of MPK3 and MPK6 in vitro |
| GO:0005515 protein binding | IPI PMID:21798944 Evidence for network evolution in an Arabidopsis interactome... | REMOVE | Summary: IPI interactions (MKK4/O80397, DGK3/Q8VZG1, MKK2/Q9S7U9) from the large-scale Arabidopsis Interactome Mapping Consortium yeast two-hybrid network. Reason: Bare protein binding from a high-throughput interactome screen; uninformative about molecular function. Supporting Evidence: PMID:21798944 Evidence for network evolution in an Arabidopsis interactome map |
| GO:0005515 protein binding | IPI PMID:32612234 Extensive signal integration by the phytohormone protein net... | REMOVE | Summary: IPI interactions (including MKK4/O80397, MKK6/Q9FJV0, MKK2/Q9S7U9, DGK3/Q8VZG1) from a large-scale phytohormone protein interaction network. Reason: Bare protein binding from a high-throughput network; uninformative about MPK6 molecular function. Supporting Evidence: PMID:32612234 Extensive signal integration by the phytohormone protein network |
| GO:0005634 nucleus | EXP PMID:31235876 Bipartite anchoring of SCREAM enforces stomatal initiation b... | ACCEPT | Summary: Experimental nuclear localization of MPK6, consistent with nuclear phosphorylation of SPEECHLESS/SCREAM in stomatal initiation and with activation-triggered nuclear translocation. Reason: Direct experimental evidence for nuclear localization; functionally important site where MPK6 phosphorylates nuclear transcription factors. Supporting Evidence: PMID:31235876 Bipartite anchoring of SCREAM enforces stomatal initiation by coupling MAP kinases to SPEECHLESS file:ARATH/MPK6/MPK6-deep-research-falcon.md classic reports note stress-triggered nuclear translocation of MAPKs |
| GO:0106310 protein serine kinase activity | EXP PMID:10713056 Microbial elicitors induce activation and dual phosphorylati... | ACCEPT | Summary: Experimental demonstration of MPK6 activation/catalytic activity; dually phosphorylated on Thr221/Tyr223 and activated by microbial elicitors. Reason: Direct experimental support for the core catalytic activity (EC 2.7.11.24). Supporting Evidence: PMID:10713056 AtMPK6 is phosphorylated on threonine and tyrosine residues in elicited cells |
| GO:0106310 protein serine kinase activity | EXP PMID:10717008 Functional analysis of oxidative stress-activated mitogen-ac... | ACCEPT | Summary: MPK6 catalytic activity demonstrated in the oxidative-stress (H2O2/ANP1) MAPK cascade where active ANP1 initiates phosphorylation of MPK3 and MPK6. Reason: Experimental support for active kinase function. Duplicate of the core MF, which is acceptable. Supporting Evidence: PMID:10717008 a phosphorylation cascade involving two stress MAPKs, AtMPK3 and AtMPK6 |
| GO:0106310 protein serine kinase activity | EXP PMID:11123804 Various abiotic stresses rapidly activate Arabidopsis MAP ki... | ACCEPT | Summary: MPK6 catalytic activity/activation by abiotic stresses (low temperature, humidity, hyperosmolarity, touch, wounding), associated with tyrosine phosphorylation. Reason: Experimental support for the core kinase activity. Duplicate MF entry, acceptable. Supporting Evidence: PMID:11123804 environmental stresses such as low temperature, low humidity, hyper-osmolarity, touch and wounding induce rapid and transient activation of the Arabidopsis MAP kinases ATMPK4 and ATMPK6 |
| GO:0106310 protein serine kinase activity | EXP PMID:11500556 Harpin induces activation of the Arabidopsis mitogen-activat... | ACCEPT | Summary: MPK6 catalytic activity/activation by the bacterial elicitor harpin in Arabidopsis cell cultures. Reason: Experimental support for the core kinase activity. Duplicate MF entry, acceptable. Supporting Evidence: PMID:11500556 harpin (secreted by Pseudomonas syringae pv syringae) activates two MAPKs in suspension cultures of Arabidopsis |
| GO:0106310 protein serine kinase activity | EXP PMID:11577197 Oxidative stress activates ATMPK6, an Arabidopsis homologue ... | ACCEPT | Summary: MPK6 catalytic activity/activation by oxidative stress (H2O2, KO2, paraquat) using anti-AtMPK6 antibody. Reason: Experimental support for the core kinase activity. Duplicate MF entry, acceptable. Supporting Evidence: PMID:11577197 ATMPK6 in T87 cells was strongly activated by reactive oxygen species (ROS) such as H(2)O(2) and KO(2) |
| GO:0106310 protein serine kinase activity | EXP PMID:12220631 Different protein kinase families are activated by osmotic s... | ACCEPT | Summary: MPK6 catalytic activity/activation by osmotic stress, identified as a MAP kinase by anti-phospho-MAPK antibodies and tyrosine-phosphatase sensitivity. Reason: Experimental support for the core kinase activity. Duplicate MF entry, acceptable. Supporting Evidence: PMID:12220631 two of the MAP kinases were identified as AtMPK6 and AtMPK3 |
| GO:0106310 protein serine kinase activity | EXP PMID:12628921 A MAPK pathway mediates ethylene signaling in plants. | ACCEPT | Summary: MPK6 catalytic activity/activation by the ethylene precursor ACC in the ethylene-signaling MAPK pathway. Reason: Experimental support for the core kinase activity. Duplicate MF entry, acceptable. Supporting Evidence: PMID:12628921 distinct MAPKs are activated by the ethylene precursor aminocyclopropane-1-carboxylic acid (ACC) in Medicago and Arabidopsis |
| GO:0106310 protein serine kinase activity | EXP PMID:15225555 The MKK2 pathway mediates cold and salt stress signaling in ... | ACCEPT | Summary: MPK6 catalytic activity demonstrated in the MKK2 cold/salt-stress MAPK cascade by in vitro and in vivo kinase assays. Reason: Experimental support for the core kinase activity. Duplicate MF entry, acceptable. Supporting Evidence: PMID:15225555 Yeast two-hybrid, in vitro, and in vivo protein kinase assays revealed that MKK2 directly targets MPK4 and MPK6 |
| GO:0106310 protein serine kinase activity | EXP PMID:15500467 Stress hormone-independent activation and nuclear translocat... | ACCEPT | Summary: MPK6 catalytic activity/activation and nuclear translocation during ozone exposure. Reason: Experimental support for the core kinase activity. Duplicate MF entry, acceptable. Supporting Evidence: PMID:15500467 transient activation of 43 and 45 kDa MAPKs. These were identified as AtMPK3 and AtMPK6 |
| GO:0106310 protein serine kinase activity | EXP PMID:21276203 The Arabidopsis protein kinase Pto-interacting 1-4 is a comm... | ACCEPT | Summary: MPK6 catalytic activity demonstrated by in vitro phosphorylation of the substrate PTI1-4/CARK3. Reason: Experimental support for the core kinase activity, with an identified substrate. Duplicate MF entry, acceptable. Supporting Evidence: PMID:21276203 OXI1 and PTI1-4 were substrates of MPK3 and MPK6 in vitro |
| GO:0004672 protein kinase activity | IMP PMID:21276203 The Arabidopsis protein kinase Pto-interacting 1-4 is a comm... | ACCEPT | Summary: Protein kinase activity supported by phosphorylation of PTI1-4/CARK3 and OXI1 substrates. More general than the serine/MAP kinase terms but correct. Reason: Valid parent-level MF annotation with experimental support, consistent with the established core kinase function. Supporting Evidence: PMID:21276203 OXI1 and PTI1-4 were substrates of MPK3 and MPK6 in vitro |
| GO:0005515 protein binding | IPI PMID:33419940 Chromatin phosphoproteomics unravels a function for AT-hook ... | REMOVE | Summary: IPI interaction with AHL13 (AT4G17950), an AT-hook nuclear protein and MPK6 phosphorylation target in PAMP-triggered immunity chromatin phosphoproteomics. Reason: Bare protein binding is uninformative; AHL13 is an MPK6 substrate in immunity, better captured by kinase activity and defense process terms. Supporting Evidence: PMID:33419940 Chromatin phosphoproteomics unravels a function for AT-hook motif nuclear localized protein AHL13 in PAMP-triggered immunity |
| GO:0005515 protein binding | IPI PMID:27913741 AIK1, A Mitogen-Activated Protein Kinase, Modulates Abscisic... | REMOVE | Summary: IPI interaction with MKK5 (Q8RXG3), the upstream MAP kinase kinase that activates MPK6 in the MKKK20/AIK1-MKK5-MPK6 ABA-response cascade. Reason: Uninformative bare protein binding; the MKK5-MPK6 relationship is captured by the MAPK cascade and ABA-signaling annotations. Supporting Evidence: PMID:27913741 AIK1, A Mitogen-Activated Protein Kinase, Modulates Abscisic Acid Responses through the MKK5-MPK6 Kinase Cascade |
| GO:0009738 abscisic acid-activated signaling pathway | IMP PMID:27913741 AIK1, A Mitogen-Activated Protein Kinase, Modulates Abscisic... | KEEP AS NON CORE | Summary: MPK6 functions downstream of MKK5 (activated by AIK1/MKKK20) in transducing ABA responses affecting root growth and stomatal closure. Reason: Well-supported by mutant phenotypes (reduced ABA sensitivity in germination, root growth, stomata). One of many hormone-signaling roles of this pleiotropic kinase. Supporting Evidence: PMID:27913741 The activity of MPK6 was increased by ABA in wild-type seedlings, but its activation by ABA was impaired in aik1 and aik1 mkk5 mutants. These findings clearly suggest that the AIK1-MKK5-MPK6 cascade functions in the ABA regulation of primary root growth and stomatal response |
| GO:0010082 regulation of root meristem growth | IMP PMID:27913741 AIK1, A Mitogen-Activated Protein Kinase, Modulates Abscisic... | KEEP AS NON CORE | Summary: MPK6 regulates root growth (root cell division and elongation) downstream of the MKK5-MPK6 ABA cascade. Reason: Supported by mpk6 root phenotypes under ABA; a specific developmental output, non-core for a pleiotropic MAPK. Supporting Evidence: PMID:27913741 AIK1 functions in ABA responses via regulation of root cell division and elongation, as well as stomatal responses. |
| GO:0051301 cell division | IMP PMID:27913741 AIK1, A Mitogen-Activated Protein Kinase, Modulates Abscisic... | KEEP AS NON CORE | Summary: MPK6 affects root cell division as part of ABA-regulated root growth control. Reason: Supported, but a downstream developmental consequence rather than core molecular function; non-core for a pleiotropic MAPK. Supporting Evidence: PMID:27913741 AIK1 functions in ABA responses via regulation of root cell division and elongation, as well as stomatal responses. |
| GO:0051510 regulation of unidimensional cell growth | IMP PMID:27913741 AIK1, A Mitogen-Activated Protein Kinase, Modulates Abscisic... | KEEP AS NON CORE | Summary: MPK6 affects cell elongation (unidimensional cell growth) in root growth control downstream of the MKK5 ABA cascade. Reason: Supported but a specific downstream growth output; non-core. Supporting Evidence: PMID:27913741 AIK1 functions in ABA responses via regulation of root cell division and elongation, as well as stomatal responses. |
| GO:0090333 regulation of stomatal closure | IMP PMID:27913741 AIK1, A Mitogen-Activated Protein Kinase, Modulates Abscisic... | KEEP AS NON CORE | Summary: MPK6 regulates the ABA-induced stomatal response; mpk6 plants are insensitive to ABA in stomatal response with increased water loss. Reason: Supported by disruption phenotype; a specific physiological output of ABA signaling, non-core. Supporting Evidence: PMID:27913741 T-DNA insertion mutants of AIK1 showed insensitivity to ABA in terms of both root growth and stomatal response. |
| GO:0005829 cytosol | HDA PMID:28887381 Global Analysis of Membrane-associated Protein Oligomerizati... | UNDECIDED | Summary: High-throughput direct assay (protein correlation profiling) localizing MPK6 to the cytosol, consistent with its predominant resting-state cytoplasmic localization. Reason: The cytosolic localization is consistent with the well-established cytoplasmic localization of MPK6, but the cached publication text (a global membrane-protein oligomerization proteomics study) does not mention MPK6/MAPK6 or its localization in the available body text; the specific assignment derives from supplementary dataset tables not present here, so no verbatim supporting excerpt can be quoted. Supporting Evidence: PMID:28887381 nondenaturing detergent solubilization and LC/MS-based profiling of size exclusion chromatography fractions |
| GO:0005515 protein binding | IPI PMID:25843888 The BASL polarity protein controls a MAPK signaling feedback... | REMOVE | Summary: IPI interactions with BASL (Q5BPF3) and YODA/YDA (Q9CAD5) in the stomatal asymmetric-cell-division feedback loop; BASL recruits MPK6 to the cell cortex and MPK6 phosphorylates BASL. Reason: Bare protein binding is uninformative; BASL is a recruiter and MPK6 substrate; the relationship is captured by kinase activity, stomatal development and cell cortex annotations. Supporting Evidence: PMID:25843888 The BASL polarity protein controls a MAPK signaling feedback loop in asymmetric cell division |
| GO:0005938 cell cortex | IDA PMID:25843888 The BASL polarity protein controls a MAPK signaling feedback... | KEEP AS NON CORE | Summary: Direct evidence that MPK6 is recruited to the cell cortex in a polarized manner by BASL during stomatal asymmetric cell division. Reason: Experimentally supported but a specialized context-dependent localization in the stomatal lineage rather than the principal site of catalysis. Supporting Evidence: PMID:25843888 Phosphorylated BASL functions as a scaffold and recruits the MAPKKK YODA and MPK3/6 to spatially concentrate signaling at the cortex |
| GO:0005634 nucleus | ISM GO_REF:0000122 | ACCEPT | Summary: Sequence-based (AtSubP) prediction of nuclear localization, consistent with experimentally confirmed nuclear localization. Reason: Computational prediction concordant with multiple experimental nuclear-localization annotations. Supporting Evidence: PMID:31235876 coupling MAP kinases to SPEECHLESS |
| GO:0019902 phosphatase binding | IPI PMID:27029354 Quantitative phosphoproteomics of protein kinase SnRK1 regul... | ACCEPT | Summary: IPI interaction with the protein tyrosine phosphatase PTP1 (O82656), a negative regulator that dephosphorylates and inactivates MPK6. Phosphatase binding is more informative than generic protein binding. Reason: Phosphatase binding is an informative MF term capturing the documented physical interaction with MPK-inactivating phosphatases (PTP1, MKP1, MKP2/DSPTP1B). Retained rather than reduced to bare protein binding. Supporting Evidence: PMID:27029354 PTP1 interacted with MPK6 in the cytoplasm and nucleus (Fig. 7, lane 4, panel 4) PMID:19789277 PROTEIN TYROSINE PHOSPHATASE1 (PTP1) also interacts with MPK6, but the ptp1 null mutant shows no aberrant growth phenotype |
| GO:1902065 response to L-glutamate | IDA PMID:29344832 Mitogen activated protein kinase 6 and MAP kinase phosphatas... | KEEP AS NON CORE | Summary: MPK6 (with the phosphatase MKP1) is involved in the response of Arabidopsis roots to L-glutamate, linking MPK6 signaling to glutamate-modulated root development. Reason: Experimentally supported but a narrow, specialized physiological response; non-core. Supporting Evidence: PMID:29344832 In-gel phosphorylation assays revealed a rapid and dose-dependent induction of MPK6 and MPK3 activities in wild-type Arabidopsis seedlings in response to L-Glu |
| GO:0005515 protein binding | IPI PMID:29056553 MPK3- and MPK6-Mediated ICE1 Phosphorylation Negatively Regu... | REMOVE | Summary: IPI interaction with ICE1 (AT3G26744), the master regulator of cold-responsive CBF genes; MPK6 phosphorylates ICE1 to negatively regulate its stability and freezing tolerance. Reason: Bare protein binding is uninformative; ICE1 is an MPK6 substrate, captured by kinase activity and the freezing-response process from the same study. Supporting Evidence: PMID:29056553 MPK3- and MPK6-Mediated ICE1 Phosphorylation Negatively Regulates ICE1 Stability and Freezing Tolerance in Arabidopsis |
| GO:0006468 protein phosphorylation | IDA PMID:29056553 MPK3- and MPK6-Mediated ICE1 Phosphorylation Negatively Regu... | ACCEPT | Summary: MPK6 directly phosphorylates ICE1, the core enzymatic process performed by this kinase; the qualifier reflects the downstream consequence on ICE1 stability. Reason: Protein phosphorylation is the direct biological process executed by MPK6 kinase activity; well-supported by direct phosphorylation of ICE1. Supporting Evidence: PMID:29056553 mitogen-activated protein kinase 3 (MPK3) and MPK6 interact with and phosphorylate ICE1, which reduces its stability and transcriptional activity |
| GO:0050826 response to freezing | IMP PMID:29056553 MPK3- and MPK6-Mediated ICE1 Phosphorylation Negatively Regu... | KEEP AS NON CORE | Summary: MPK6 negatively regulates freezing tolerance via phosphorylation-dependent destabilization of ICE1, dampening CBF-mediated cold acclimation. Reason: Experimentally supported physiological role, but one of many stress responses; non-core. Supporting Evidence: PMID:29056553 the mpk3 and mpk6 single mutants and the mpk3 mpk6 double mutants show enhanced freezing tolerance, whereas MPK3/MPK6 activation attenuates freezing tolerance file:ARATH/MPK6/MPK6-deep-research-falcon.md compiled substrates include **MYB41, MYB15, HsfA2, ICE1, DCP1** among others, with outcomes such as enhanced DNA binding, altered protein stability, and nuclear accumulation. |
| GO:0005515 protein binding | IPI PMID:22575450 Phosphorylation by AtMPK6 is required for the biological fun... | REMOVE | Summary: IPI interaction with MYB41 (Q9M0J5), a transcription factor and MPK6 substrate; phosphorylation at Ser251 enhances its DNA binding and salt-tolerance function. Reason: Bare protein binding is uninformative; MYB41 is an MPK6 substrate captured by kinase activity. Supporting Evidence: PMID:22575450 MYB41 was phosphorylated by recombinant MPK6 as well as by plant MPK6. Ser(251) in MYB41 was identified as the site phosphorylated by MPK6 |
| GO:0005515 protein binding | IPI PMID:24750137 The Arabidopsis thaliana mitogen-activated protein kinases M... | REMOVE | Summary: IPI interactions with VQ-motif proteins VQ4 (O82170) and IKU1/VQ14 (Q5M750), MPK3/MPK6 substrates regulating immune responses. Reason: Bare protein binding is uninformative; VQ proteins are MPK6 substrates in immunity, captured by kinase activity and defense annotations. Supporting Evidence: PMID:24750137 The Arabidopsis thaliana mitogen-activated protein kinases MPK3 and MPK6 target a subclass of 'VQ-motif'-containing proteins to regulate immune responses |
| GO:0005515 protein binding | IPI PMID:25010425 Arabidopsis LIP5, a positive regulator of multivesicular bod... | REMOVE | Summary: IPI interaction with LIP5 (Q9SZ15), a positive regulator of multivesicular body biogenesis and MPK6 substrate in pathogen-responsive basal defense. Reason: Bare protein binding is uninformative; LIP5 is an MPK6 substrate, captured by kinase activity and defense process terms. Supporting Evidence: PMID:25010425 LIP5 is a target of pathogen-responsive mitogen-activated protein kinases (MPKs) and plays a critical role in plant basal resistance |
| GO:0009555 pollen development | IGI PMID:24830428 Phosphorylation of a WRKY transcription factor by MAPKs is r... | KEEP AS NON CORE | Summary: MPK6 (with MPK3) phosphorylates the pollen-specific transcription factor WRKY34 (and WRKY2), required for male gametogenesis and pollen development. Reason: Supported by genetic interaction and substrate phosphorylation, but a specialized developmental role; non-core. Supporting Evidence: PMID:24830428 epitope-tagged WRKY34 is temporally phosphorylated by MPK3 and MPK6, two mitogen-activated protein kinases (MAPKs, or MPKs), at early stages in pollen development |
| GO:0010183 pollen tube guidance | IGI PMID:24717717 Two Mitogen-Activated Protein Kinases, MPK3 and MPK6, Are Re... | KEEP AS NON CORE | Summary: MPK3 and MPK6 are required for funicular guidance of pollen tubes; mpk3 mpk6 mutant pollen has reduced transmission. Reason: Supported by genetic analysis, but a specialized reproductive function; non-core. Supporting Evidence: PMID:24717717 MPK3 and MPK6, two Arabidopsis (Arabidopsis thaliana) mitogen-activated protein kinases, mediate the guidance response in pollen tubes |
| GO:0009620 response to fungus | IEP PMID:21947882 Expression analysis of MAP2K9 and MAPK6 during pathogenesis ... | KEEP AS NON CORE | Summary: MAPK6 expression is induced during Alternaria brassicae blight pathogenesis, implicating it in the response to fungal infection (expression evidence only). Reason: Expression-based evidence consistent with the broader immunity role of MPK6; non-core specific stimulus response. Supporting Evidence: PMID:21947882 It was observed that the expression of both MAP2K9 and MAPK6 simultaneously increased up to middle stage of disease progression |
| GO:0010150 leaf senescence | IMP PMID:19251906 An arabidopsis mitogen-activated protein kinase cascade, MKK... | KEEP AS NON CORE | Summary: The MKK9-MPK6 cascade positively regulates leaf senescence; mpk6 knockout delays senescence and MKK9-induced premature senescence is suppressed in mpk6. Reason: Well-supported by mutant/overexpression phenotypes, but a specific developmental output; non-core for a pleiotropic kinase. Supporting Evidence: PMID:19251906 a MAPK cascade involving MKK9-MPK6 is shown to play an important role in regulating leaf senescence in Arabidopsis |
| GO:0010229 inflorescence development | IMP PMID:23263767 A MAPK cascade downstream of ERECTA receptor-like protein ki... | KEEP AS NON CORE | Summary: The ER-MKK4/MKK5-MPK3/MPK6 cascade regulates inflorescence architecture by promoting localized cell proliferation; loss of MPK3/MPK6 phenocopies er (shortened pedicels, clustered inflorescences). Reason: Well-supported developmental role downstream of ERECTA; non-core. Supporting Evidence: PMID:23263767 loss of function of MPK3/MPK6 or their upstream MAPK kinases (MAPKKs; or MKKs), MKK4/MKK5, resulted in shortened pedicels and clustered inflorescences |
| GO:0004672 protein kinase activity | IDA PMID:22631074 Determination of primary sequence specificity of Arabidopsis... | ACCEPT | Summary: Direct demonstration of MPK6 kinase activity and substrate specificity (preference for L/P-x-S-P-R/K) using a positional peptide library and in vitro kinase assays. Reason: Strong direct experimental support for the core kinase activity, including definition of the substrate consensus motif. Supporting Evidence: PMID:22631074 a preference towards the sequence L/P-P/X-S-P-R/K for both kinases file:ARATH/MPK6/MPK6-deep-research-falcon.md MPK6 functions as a proline-directed MAP kinase that phosphorylates downstream substrates including transcription factors, enzymes, RNA-metabolism proteins, and developmental regulators, often redundantly with MPK3. |
| GO:0005515 protein binding | IPI PMID:19789277 MAP kinase phosphatase1 and protein tyrosine phosphatase1 ar... | REMOVE | Summary: IPI interaction with the phosphatase MKP1/PTP1 (O82656), negative regulators that dephosphorylate MPK6 and repress salicylic-acid synthesis and SNC1-mediated responses. Reason: Bare protein binding is uninformative. This phosphatase interaction is better represented by the phosphatase binding (GO:0019902) annotation, which is retained. Supporting Evidence: PMID:19789277 The dual-specificity phosphatase MAP KINASE PHOSPHATASE1 (MKP1) was previously shown to regulate MAP KINASE6 (MPK6) activation levels |
| GO:0005515 protein binding | IPI PMID:20626661 MAPK phosphatase MKP2 mediates disease responses in Arabidop... | REMOVE | Summary: IPI interaction with MKP2/DSPTP1B (Q9M8K7), a MAPK phosphatase that negatively regulates MPK6 and functions in disease responses, especially during HR-like responses. Reason: Bare protein binding is uninformative; this phosphatase regulatory interaction is captured by the phosphatase binding annotation (GO:0019902). Supporting Evidence: PMID:20626661 MAPK phosphatase 2 (MKP2) regulates oxidative stress and pathogen defence responses and functionally interacts with MPK3 and MPK6 |
| GO:0010224 response to UV-B | IMP PMID:21790814 Arabidopsis MAP kinase phosphatase 1 and its target MAP kina... | KEEP AS NON CORE | Summary: MPK6 (with MPK3 and the phosphatase MKP1) antagonistically determines UV-B stress tolerance, independent of the UVR8 photoreceptor pathway. Reason: Experimentally supported stress-response role; non-core for a pleiotropic kinase. Supporting Evidence: PMID:21790814 The MKP1-interacting proteins MPK3 and MPK6 are activated by UV-B stress and are hyperactivated in mkp1. Moreover, mutants mpk3 and mpk6 exhibit elevated UV-B tolerance |
| GO:0005802 trans-Golgi network | IDA PMID:19832943 Arabidopsis MPK6 is involved in cell division plane control ... | KEEP AS NON CORE | Summary: MPK6 localizes to the trans-Golgi network (and plasma membrane) in dividing root cells, by subcellular fractionation and in situ/in vivo co-localization. Reason: Experimentally supported localization in dividing root cells, but a specialized compartment relative to the principal cytoplasmic/nuclear sites. Supporting Evidence: PMID:19832943 MPK6 was localized to the plasma membrane (PM) and the trans-Golgi network (TGN) |
| GO:0009524 phragmoplast | IDA PMID:19832943 Arabidopsis MPK6 is involved in cell division plane control ... | KEEP AS NON CORE | Summary: MPK6 localizes to distinct fine spots in the phragmoplast, a cytoskeletal structure controlling the cell division plane in dividing root cells. Reason: Experimentally supported localization linked to cell-division-plane control; specialized, non-core. Supporting Evidence: PMID:19832943 MPK6 was localized on the subcellular level to distinct fine spots in the pre-prophase band and phragmoplast |
| GO:0009574 preprophase band | IDA PMID:19832943 Arabidopsis MPK6 is involved in cell division plane control ... | KEEP AS NON CORE | Summary: MPK6 localizes to distinct fine spots in the preprophase band in dividing root cells. Reason: Experimentally supported localization linked to cell-division-plane control; specialized, non-core. Supporting Evidence: PMID:19832943 MPK6 was localized on the subcellular level to distinct fine spots in the pre-prophase band and phragmoplast |
| GO:0048364 root development | IMP PMID:19832943 Arabidopsis MPK6 is involved in cell division plane control ... | KEEP AS NON CORE | Summary: MPK6 is involved in early root development; mpk6 knockouts show 'no root'/'short root' phenotypes with ectopic and aberrant cell divisions. Reason: Supported by mutant phenotypes, but a specialized developmental output; non-core. Supporting Evidence: PMID:19832943 'no root' and 'short root' phenotypes, as well as with ectopic cell divisions and aberrant cell division planes, resulting in disordered cell files in the roots of these mpk6 knock-out mutants |
| GO:0051301 cell division | IMP PMID:19832943 Arabidopsis MPK6 is involved in cell division plane control ... | KEEP AS NON CORE | Summary: MPK6 controls cell-division plane orientation during early root development; mpk6 mutants show aberrant cell division planes. Reason: Supported by mutant phenotypes (cell-division involvement from a developmental study); non-core for a pleiotropic kinase. Supporting Evidence: PMID:19832943 MPK6 is involved in cell division plane control during early root development |
| GO:0080136 priming of cellular response to stress | IMP PMID:19318610 Mitogen-activated protein kinases 3 and 6 are required for f... | KEEP AS NON CORE | Summary: MPK3 and MPK6 are required for full priming of stress responses (induced resistance), accumulating as latent signaling components used upon challenge. Reason: Experimentally supported, but a specialized defense-priming role; non-core. Supporting Evidence: PMID:19318610 priming is associated with accumulation of mRNA and inactive proteins of mitogen-activated protein kinases (MPKs), MPK3 and MPK6. Upon challenge exposure to biotic or abiotic stress, these two enzymes were more strongly activated in primed plants than in nonprimed plants |
| GO:0009651 response to salt stress | IGI PMID:15225555 The MKK2 pathway mediates cold and salt stress signaling in ... | KEEP AS NON CORE | Summary: MPK6 functions downstream of MKK2 in salt-stress signaling; mkk2 plants impaired in MPK4/MPK6 activation are salt hypersensitive. Reason: Supported genetically (MKK2 pathway); one of many abiotic-stress responses; non-core. Supporting Evidence: PMID:15225555 mkk2 null plants were impaired in MPK4 and MPK6 activation and were hypersensitive to salt and cold stress |
| GO:0048481 plant ovule development | IGI PMID:18364464 Haplo-insufficiency of MPK3 in MPK6 mutant background uncove... | KEEP AS NON CORE | Summary: MPK3 and MPK6 share a function in ovule development, revealed by haplo-insufficiency of MPK3 in the mpk6 mutant background. Reason: Supported by genetic interaction; a specialized reproductive-development role; non-core. Supporting Evidence: PMID:18364464 two closely related mitogen-activated protein kinases in Arabidopsis thaliana, MPK3 and MPK6, share a novel function in ovule development: in the MPK6 mutant background, MPK3 is haplo-insufficient, giving female sterility when heterozygous |
| GO:0009737 response to abscisic acid | IEP PMID:18248592 AtMKK1 mediates ABA-induced CAT1 expression and H2O2 product... | KEEP AS NON CORE | Summary: The MKK1-MPK6 module mediates ABA-induced CAT1 expression and H2O2 production; ABA increases MPK6 activity in an MKK1-dependent manner. Reason: Supported by mutant and expression evidence; ABA response is one of several hormone roles; non-core. Supporting Evidence: PMID:18248592 The activity of AtMPK6 was increased by ABA in an AtMKK1-dependent manner |
| GO:0010120 camalexin biosynthetic process | IMP PMID:18378893 A fungal-responsive MAPK cascade regulates phytoalexin biosy... | KEEP AS NON CORE | Summary: The MPK3/MPK6 cascade regulates camalexin (phytoalexin) biosynthesis through transcriptional regulation of biosynthetic genes after pathogen infection; camalexin induction is compromised in mpk6 mutants. Reason: Well-supported by mutant phenotypes; a specific defense-metabolism output of MPK6 immune signaling; non-core. Supporting Evidence: PMID:18378893 synthesis of camalexin, the major phytoalexin in Arabidopsis, is regulated by the MPK3/MPK6 cascade |
| GO:0042542 response to hydrogen peroxide | IDA PMID:17933903 The Arabidopsis mitogen-activated protein kinase kinase MKK3... | KEEP AS NON CORE | Summary: MPK6 (a group C/related MAPK target of MKK3) is activated in pathogen/oxidative signaling; H2O2 is a potent activator of MPK6. Reason: Supported; H2O2/ROS responsiveness is well established but one of many stimulus responses; non-core. Supporting Evidence: PMID:17933903 MPK6 and MPK7 were both activated by H(2)O(2), but only MPK7 activation was enhanced by MKK3 |
| GO:0009864 induced systemic resistance, jasmonic acid mediated signaling pathway | IMP PMID:17369371 The mitogen-activated protein kinase cascade MKK3-MPK6 is an... | KEEP AS NON CORE | Summary: The MKK3-MPK6 cascade is an important part of the jasmonate signal transduction pathway, negatively regulating MYC2/JIN1 expression. Reason: Supported by genetic gain/loss-of-function analyses; a specific JA-signaling role; non-core. Supporting Evidence: PMID:17369371 we identify a mitogen-activated protein kinase (MAPK) cascade, MAPK KINASE 3 (MKK3)-MAPK 6 (MPK6), which is activated by JA in Arabidopsis |
| GO:0042742 defense response to bacterium | IEP PMID:11875555 MAP kinase signalling cascade in Arabidopsis innate immunity... | KEEP AS NON CORE | Summary: MPK6 (in the MEKK1-MKK4/MKK5-MPK3/MPK6 cascade downstream of FLS2) confers resistance to bacterial pathogens; K92M/K93M kinase-dead mutants establish the requirement for kinase activity. Reason: Strongly supported core immunity output, but a specific biological process among many; non-core for a pleiotropic kinase. The underlying core is the MAPK cascade / kinase activity. Supporting Evidence: PMID:11875555 Activation of this MAPK cascade confers resistance to both bacterial and fungal pathogens file:ARATH/MPK6/MPK6-deep-research-falcon.md the **MEKK1–MKK4/5–MPK3/MPK6** PTI module downstream of FLS2 that contributes to pathogen resistance |
| GO:0000302 response to reactive oxygen species | IEP PMID:11577197 Oxidative stress activates ATMPK6, an Arabidopsis homologue ... | KEEP AS NON CORE | Summary: MPK6 is strongly activated by reactive oxygen species (H2O2, KO2), implicating it as a candidate signal mediator in abiotic/biotic ROS responses. Reason: Supported; ROS responsiveness is well established but one of many stimulus responses; non-core. Supporting Evidence: PMID:11577197 ATMPK6 in T87 cells was strongly activated by reactive oxygen species (ROS) such as H(2)O(2) and KO(2) |
| GO:0004707 MAP kinase activity | IDA PMID:10713056 Microbial elicitors induce activation and dual phosphorylati... | ACCEPT | Summary: Direct experimental demonstration of MPK6 MAP kinase activity and dual Thr/Tyr phosphorylation upon elicitor treatment. The core molecular function. Reason: Direct experimental support for the defining core MF (EC 2.7.11.24). Duplicate of the IEA MAP kinase activity entry, which is appropriate. Supporting Evidence: PMID:10713056 AtMPK6 is phosphorylated on threonine and tyrosine residues in elicited cells file:ARATH/MPK6/MPK6-deep-research-falcon.md terminal kinase in MAPK cascades activated by dual Thr/Tyr phosphorylation in the TxY motif |
| GO:0006970 response to osmotic stress | IDA PMID:12220631 Different protein kinase families are activated by osmotic s... | KEEP AS NON CORE | Summary: MPK6 is activated by osmotic (hypoosmotic/hyperosmotic) stresses in Arabidopsis cell suspensions. Reason: Supported; osmotic-stress responsiveness is well established but one of many stimulus responses; non-core. Supporting Evidence: PMID:12220631 two of the MAP kinases were identified as AtMPK6 and AtMPK3 |
| GO:0006979 response to oxidative stress | IEP PMID:10717008 Functional analysis of oxidative stress-activated mitogen-ac... | KEEP AS NON CORE | Summary: MPK6 functions in the H2O2/ANP1-initiated oxidative-stress MAPK cascade (ANP1-MPK3/MPK6) inducing stress-responsive genes. Reason: Supported; oxidative-stress signaling is a well-established MPK6 role but one of many; non-core. Supporting Evidence: PMID:10717008 a phosphorylation cascade involving two stress MAPKs, AtMPK3 and AtMPK6 |
| GO:0009409 response to cold | IDA PMID:15225555 The MKK2 pathway mediates cold and salt stress signaling in ... | KEEP AS NON CORE | Summary: MPK6 functions downstream of MKK2 in cold-stress signaling; mkk2 plants are cold hypersensitive while MKK2 overexpression confers freezing tolerance. Reason: Supported by the MKK2 pathway study; cold signaling is one of multiple stress roles; non-core. Supporting Evidence: PMID:15225555 plants overexpressing MKK2 exhibited constitutive MPK4 and MPK6 activity ... and increased freezing and salt tolerance |
| GO:0009723 response to ethylene | IDA PMID:12628921 A MAPK pathway mediates ethylene signaling in plants. | KEEP AS NON CORE | Summary: MPK6 is activated by the ethylene precursor ACC and acts in the ethylene signal transduction pathway (downstream of ETR1/CTR1; constitutively active in ctr1). Reason: Supported; ethylene signaling (including phosphorylation of ACS2/ACS6 and EIN3) is a well-established MPK6 role but one of several hormone pathways; non-core. Supporting Evidence: PMID:12628921 ctr1 mutants showed constitutive activation of MPK6. These data indicate that a MAPK cascade is part of the ethylene signal transduction pathway in plants file:ARATH/MPK6/MPK6-deep-research-falcon.md MPK6 phosphorylates ACC synthase isoforms (e.g., ACS6) to affect stability and ethylene output |
| GO:0007165 signal transduction | IC PMID:12119167 Mitogen-activated protein kinase cascades in plants: a new n... | ACCEPT | Summary: Curator inference (from MAP kinase activity) that MPK6 functions in signal transduction, per the MAPK nomenclature review describing MAPK cascades as universal signal transduction modules. Reason: Correct high-level process annotation, consistent with the IEA/IBA signal-transduction terms. More specific MAPK cascade terms are also present. Supporting Evidence: PMID:12119167 Mitogen-activated protein kinase (MAPK) cascades are universal signal transduction modules in eukaryotes |
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Q: To what extent are individual MPK6 biological-process annotations attributable to MPK6 specifically versus shared redundantly with MPK3, and which outputs are MPK6-unique?
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