BAK1

Existing Annotations Review

GO Term	Evidence	Action	Reason
GO:0140426 pathogen-associated molecular pattern receptor signaling pathway	IMP PMID:17626179 The receptor-like kinase SERK3/BAK1 is a central regulator o...	NEW	Summary: BAK1/SERK3 functions as a co-receptor kinase in FLS2/EFR/CERK-family pattern-recognition receptor complexes. Reason: PMID:17626179 shows that loss of SERK3/BAK1 reduces early flg22-dependent responses and that BAK1 rapidly enters a ligand-dependent complex with FLS2, directly supporting IMP curation to the PAMP receptor signaling pathway. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes. PMID:17626179 AtSERK3/BAK1 rapidly enters an elicitor-dependent complex with FLAGELLIN SENSING 2 (FLS2), the receptor for the bacterial PAMP flagellin and its peptide derivative flg22.
GO:0002229 defense response to oomycetes	IMP PMID:17583510 The BRI1-associated kinase 1, BAK1, has a brassinolide-indep...	KEEP AS NON CORE	Summary: BAK1 contributes to defense response to oomycetes through pattern-recognition receptor and cell-death signaling complexes. Reason: The phenotype/process is supported as a downstream immune output, but BAK1's core role is receptor-like kinase co-receptor signaling rather than being a pathogen-response effector itself.
GO:0009626 plant-type hypersensitive response	IMP PMID:18667726 Arabidopsis SOMATIC EMBRYOGENESIS RECEPTOR KINASE proteins s...	KEEP AS NON CORE	Summary: BAK1 contributes to plant-type hypersensitive response through pattern-recognition receptor and cell-death signaling complexes. Reason: The phenotype/process is supported as a downstream immune output, but BAK1's core role is receptor-like kinase co-receptor signaling rather than being a pathogen-response effector itself.
GO:0009742 brassinosteroid mediated signaling pathway	IMP PMID:18667726 Arabidopsis SOMATIC EMBRYOGENESIS RECEPTOR KINASE proteins s...	ACCEPT	Summary: BAK1/SERK3 is a BRI1-associated co-receptor kinase required for normal brassinosteroid signaling outputs. Reason: Brassinosteroid receptor-complex signaling is one of the two best-supported core biological roles of BAK1. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0009742 brassinosteroid mediated signaling pathway	IGI PMID:22253607 Genetic evidence for an indispensable role of somatic embryo...	ACCEPT	Summary: BAK1/SERK3 is a BRI1-associated co-receptor kinase required for normal brassinosteroid signaling outputs. Reason: Brassinosteroid receptor-complex signaling is one of the two best-supported core biological roles of BAK1. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0042742 defense response to bacterium	IMP PMID:17583510 The BRI1-associated kinase 1, BAK1, has a brassinolide-indep...	KEEP AS NON CORE	Summary: BAK1 contributes to defense response to bacterium through pattern-recognition receptor and cell-death signaling complexes. Reason: The phenotype/process is supported as a downstream immune output, but BAK1's core role is receptor-like kinase co-receptor signaling rather than being a pathogen-response effector itself.
GO:0050832 defense response to fungus	IMP PMID:17583510 The BRI1-associated kinase 1, BAK1, has a brassinolide-indep...	KEEP AS NON CORE	Summary: BAK1 contributes to defense response to fungus through pattern-recognition receptor and cell-death signaling complexes. Reason: The phenotype/process is supported as a downstream immune output, but BAK1's core role is receptor-like kinase co-receptor signaling rather than being a pathogen-response effector itself.
GO:0004672 protein kinase activity	IEA GO_REF:0000002	MODIFY	Summary: BAK1 has catalytic activity as a membrane receptor-like Ser/Thr kinase, but protein kinase activity is less precise for this protein. Reason: The transmembrane receptor protein serine/threonine kinase activity term captures both the catalytic activity and receptor-like membrane context. Proposed replacements: transmembrane receptor protein serine/threonine kinase activity Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0004672 protein kinase activity	IDA PMID:21680842 Direct ubiquitination of pattern recognition receptor FLS2 a...	MODIFY	Summary: BAK1 has catalytic activity as a membrane receptor-like Ser/Thr kinase, but protein kinase activity is less precise for this protein. Reason: The transmembrane receptor protein serine/threonine kinase activity term captures both the catalytic activity and receptor-like membrane context. Proposed replacements: transmembrane receptor protein serine/threonine kinase activity Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0004674 protein serine/threonine kinase activity	IEA GO_REF:0000003	MODIFY	Summary: BAK1 has catalytic activity as a membrane receptor-like Ser/Thr kinase, but protein serine/threonine kinase activity is less precise for this protein. Reason: The transmembrane receptor protein serine/threonine kinase activity term captures both the catalytic activity and receptor-like membrane context. Proposed replacements: transmembrane receptor protein serine/threonine kinase activity Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0004674 protein serine/threonine kinase activity	IDA PMID:12150929 BAK1, an Arabidopsis LRR receptor-like protein kinase, inter...	MODIFY	Summary: BAK1 has catalytic activity as a membrane receptor-like Ser/Thr kinase, but protein serine/threonine kinase activity is less precise for this protein. Reason: The transmembrane receptor protein serine/threonine kinase activity term captures both the catalytic activity and receptor-like membrane context. Proposed replacements: transmembrane receptor protein serine/threonine kinase activity Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0004713 protein tyrosine kinase activity	IEA GO_REF:0000116	MODIFY	Summary: BAK1 has catalytic activity as a membrane receptor-like Ser/Thr kinase, but protein tyrosine kinase activity is less precise for this protein. Reason: The transmembrane receptor protein serine/threonine kinase activity term captures both the catalytic activity and receptor-like membrane context. Proposed replacements: transmembrane receptor protein serine/threonine kinase activity Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0004714 transmembrane receptor protein tyrosine kinase activity	IEA GO_REF:0000003	MODIFY	Summary: BAK1 has catalytic activity as a membrane receptor-like Ser/Thr kinase, but transmembrane receptor protein tyrosine kinase activity is less precise for this protein. Reason: The transmembrane receptor protein serine/threonine kinase activity term captures both the catalytic activity and receptor-like membrane context. Proposed replacements: transmembrane receptor protein serine/threonine kinase activity Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005102 signaling receptor binding	IPI PMID:26320950 Differential Function of Arabidopsis SERK Family Receptor-li...	ACCEPT	Summary: BAK1 binds ligand-activated receptors such as BIR-regulated LRR-RLK complexes as a signaling co-receptor. Reason: Signaling receptor binding is a specific molecular role for BAK1 as an LRR-RLK co-receptor. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005515 protein binding	IPI PMID:12150928 BRI1/BAK1, a receptor kinase pair mediating brassinosteroid ...	MARK AS OVER ANNOTATED	Summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex context. Reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation is receptor kinase/co-receptor complex binding and signaling. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005515 protein binding	IPI PMID:12150929 BAK1, an Arabidopsis LRR receptor-like protein kinase, inter...	MARK AS OVER ANNOTATED	Summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex context. Reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation is receptor kinase/co-receptor complex binding and signaling. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005515 protein binding	IPI PMID:15548744 Heterodimerization and endocytosis of Arabidopsis brassinost...	MARK AS OVER ANNOTATED	Summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex context. Reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation is receptor kinase/co-receptor complex binding and signaling. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005515 protein binding	IPI PMID:16473966 The Arabidopsis SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE1 ...	MARK AS OVER ANNOTATED	Summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex context. Reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation is receptor kinase/co-receptor complex binding and signaling. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005515 protein binding	IPI PMID:16857903 Brassinosteroids regulate dissociation of BKI1, a negative r...	MARK AS OVER ANNOTATED	Summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex context. Reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation is receptor kinase/co-receptor complex binding and signaling. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005515 protein binding	IPI PMID:17625569 A flagellin-induced complex of the receptor FLS2 and BAK1 in...	MARK AS OVER ANNOTATED	Summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex context. Reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation is receptor kinase/co-receptor complex binding and signaling. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005515 protein binding	IPI PMID:17626179 The receptor-like kinase SERK3/BAK1 is a central regulator o...	MARK AS OVER ANNOTATED	Summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex context. Reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation is receptor kinase/co-receptor complex binding and signaling. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005515 protein binding	IPI PMID:19452453 Proteomic profiling of tandem affinity purified 14-3-3 prote...	MARK AS OVER ANNOTATED	Summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex context. Reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation is receptor kinase/co-receptor complex binding and signaling. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005515 protein binding	IPI PMID:19532123 Membrane steroid-binding protein 1 (MSBP1) negatively regula...	MARK AS OVER ANNOTATED	Summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex context. Reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation is receptor kinase/co-receptor complex binding and signaling. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005515 protein binding	IPI PMID:19616764 Regulation of cell death and innate immunity by two receptor...	MARK AS OVER ANNOTATED	Summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex context. Reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation is receptor kinase/co-receptor complex binding and signaling. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005515 protein binding	IPI PMID:20018686 A receptor-like cytoplasmic kinase, BIK1, associates with a ...	MARK AS OVER ANNOTATED	Summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex context. Reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation is receptor kinase/co-receptor complex binding and signaling. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005515 protein binding	IPI PMID:21499263 Stem-cell-triggered immunity through CLV3p-FLS2 signalling.	MARK AS OVER ANNOTATED	Summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex context. Reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation is receptor kinase/co-receptor complex binding and signaling. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005515 protein binding	IPI PMID:22087006 Brassinosteroids inhibit pathogen-associated molecular patte...	MARK AS OVER ANNOTATED	Summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex context. Reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation is receptor kinase/co-receptor complex binding and signaling. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005515 protein binding	IPI PMID:22184234 Deactivation of the Arabidopsis BRASSINOSTEROID INSENSITIVE ...	MARK AS OVER ANNOTATED	Summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex context. Reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation is receptor kinase/co-receptor complex binding and signaling. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005515 protein binding	IPI PMID:24114786 Structural basis for flg22-induced activation of the Arabido...	MARK AS OVER ANNOTATED	Summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex context. Reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation is receptor kinase/co-receptor complex binding and signaling. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005515 protein binding	IPI PMID:24388849 The leucine-rich repeat receptor kinase BIR2 is a negative r...	MARK AS OVER ANNOTATED	Summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex context. Reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation is receptor kinase/co-receptor complex binding and signaling. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005515 protein binding	IPI PMID:24556575 Structure of the pseudokinase domain of BIR2, a regulator of...	MARK AS OVER ANNOTATED	Summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex context. Reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation is receptor kinase/co-receptor complex binding and signaling. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005515 protein binding	IPI PMID:24625928 A bacterial tyrosine phosphatase inhibits plant pattern reco...	MARK AS OVER ANNOTATED	Summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex context. Reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation is receptor kinase/co-receptor complex binding and signaling. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005515 protein binding	IPI PMID:26308901 Allosteric receptor activation by the plant peptide hormone ...	MARK AS OVER ANNOTATED	Summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex context. Reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation is receptor kinase/co-receptor complex binding and signaling. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005515 protein binding	IPI PMID:27229311 Signature motif-guided identification of receptors for pepti...	MARK AS OVER ANNOTATED	Summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex context. Reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation is receptor kinase/co-receptor complex binding and signaling. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005515 protein binding	IPI PMID:27317676 The Arabidopsis Malectin-Like/LRR-RLK IOS1 Is Critical for B...	MARK AS OVER ANNOTATED	Summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex context. Reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation is receptor kinase/co-receptor complex binding and signaling. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005515 protein binding	IPI PMID:29320478 An extracellular network of Arabidopsis leucine-rich repeat ...	MARK AS OVER ANNOTATED	Summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex context. Reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation is receptor kinase/co-receptor complex binding and signaling. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005515 protein binding	IPI PMID:30806640 Map of physical interactions between extracellular domains o...	MARK AS OVER ANNOTATED	Summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex context. Reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation is receptor kinase/co-receptor complex binding and signaling. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005515 protein binding	IPI PMID:32327536 STRESS INDUCED FACTOR 2 Regulates Arabidopsis Stomatal Immun...	MARK AS OVER ANNOTATED	Summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex context. Reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation is receptor kinase/co-receptor complex binding and signaling. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005515 protein binding	IPI PMID:33514716 Perception of a divergent family of phytocytokines by the Ar...	MARK AS OVER ANNOTATED	Summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex context. Reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation is receptor kinase/co-receptor complex binding and signaling. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005515 protein binding	IPI PMID:35087541 The Phloem Intercalated With Xylem-Correlated 3 Receptor-Lik...	MARK AS OVER ANNOTATED	Summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex context. Reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation is receptor kinase/co-receptor complex binding and signaling. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005524 ATP binding	IEA GO_REF:0000002	KEEP AS NON CORE	Summary: ATP binding is expected for the BAK1 kinase domain. Reason: This is compatible with kinase activity but less informative than receptor Ser/Thr kinase activity.
GO:0033612 receptor serine/threonine kinase binding	IPI PMID:19616764 Regulation of cell death and innate immunity by two receptor...	ACCEPT	Summary: BAK1 physically associates with receptor serine/threonine kinases in immune and growth signaling receptor complexes. Reason: This specific binding term captures BAK1 co-receptor complex assembly better than generic protein binding. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes. PMID:19616764 Upon recognition of bacterial flagellin, the plant receptor FLS2 heterodimerizes with brassinosteroid insensitive 1-associated receptor kinase 1 (BAK1).
GO:0033612 receptor serine/threonine kinase binding	IPI PMID:26320950 Differential Function of Arabidopsis SERK Family Receptor-li...	ACCEPT	Summary: BAK1 physically associates with receptor serine/threonine kinases in immune and growth signaling receptor complexes. Reason: This specific binding term captures BAK1 co-receptor complex assembly better than generic protein binding. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes. PMID:26320950 BAK1 could co-immunoprecipitate both ER and ERL1 when expressed under the control of their native promoters in transgenic Arabidopsis plants, indicating that they associate in vivo.
GO:0042802 identical protein binding	IPI PMID:20018686 A receptor-like cytoplasmic kinase, BIK1, associates with a ...	MARK AS OVER ANNOTATED	Summary: High-throughput or interaction evidence suggests BAK1 self-association or same-protein network context. Reason: Identical protein binding is not the informative molecular function for BAK1 and should not be treated as a core annotation.
GO:0042802 identical protein binding	IPI PMID:29320478 An extracellular network of Arabidopsis leucine-rich repeat ...	MARK AS OVER ANNOTATED	Summary: High-throughput or interaction evidence suggests BAK1 self-association or same-protein network context. Reason: Identical protein binding is not the informative molecular function for BAK1 and should not be treated as a core annotation.
GO:0046982 protein heterodimerization activity	IPI PMID:15548744 Heterodimerization and endocytosis of Arabidopsis brassinost...	ACCEPT	Summary: BAK1 forms heteromeric receptor complexes with BRI1/FLS2-family receptors after ligand perception. Reason: Protein heterodimerization is a supported molecular feature of BAK1 receptor complex formation. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes. PMID:15548744 BRI1 and AtSERK3 preferentially heterodimerize in the endosomes.
GO:0106310 protein serine kinase activity	IEA GO_REF:0000116	MODIFY	Summary: BAK1 has catalytic activity as a membrane receptor-like Ser/Thr kinase, but protein serine kinase activity is less precise for this protein. Reason: The transmembrane receptor protein serine/threonine kinase activity term captures both the catalytic activity and receptor-like membrane context. Proposed replacements: transmembrane receptor protein serine/threonine kinase activity Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005768 endosome	IDA PMID:15548744 Heterodimerization and endocytosis of Arabidopsis brassinost...	KEEP AS NON CORE	Summary: BAK1 receptor complexes can undergo endocytic trafficking after signaling activation. Reason: Endosome/endosome membrane localization is a supported trafficking state but secondary to the plasma membrane co-receptor role.
GO:0005886 plasma membrane	IEA GO_REF:0000044	ACCEPT	Summary: BAK1 is a single-pass plasma-membrane receptor-like kinase/co-receptor. Reason: Plasma membrane localization is central to BAK1 function in cell-surface receptor complexes. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005886 plasma membrane	ISM GO_REF:0000122	ACCEPT	Summary: BAK1 is a single-pass plasma-membrane receptor-like kinase/co-receptor. Reason: Plasma membrane localization is central to BAK1 function in cell-surface receptor complexes. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005886 plasma membrane	IDA PMID:12150928 BRI1/BAK1, a receptor kinase pair mediating brassinosteroid ...	ACCEPT	Summary: BAK1 is a single-pass plasma-membrane receptor-like kinase/co-receptor. Reason: Plasma membrane localization is central to BAK1 function in cell-surface receptor complexes. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005886 plasma membrane	EXP PMID:12150929 BAK1, an Arabidopsis LRR receptor-like protein kinase, inter...	ACCEPT	Summary: BAK1 is a single-pass plasma-membrane receptor-like kinase/co-receptor. Reason: Plasma membrane localization is central to BAK1 function in cell-surface receptor complexes. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005886 plasma membrane	HDA PMID:14506206 Large-scale analysis of in vivo phosphorylated membrane prot...	ACCEPT	Summary: BAK1 is a single-pass plasma-membrane receptor-like kinase/co-receptor. Reason: Plasma membrane localization is central to BAK1 function in cell-surface receptor complexes. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005886 plasma membrane	EXP PMID:15548744 Heterodimerization and endocytosis of Arabidopsis brassinost...	ACCEPT	Summary: BAK1 is a single-pass plasma-membrane receptor-like kinase/co-receptor. Reason: Plasma membrane localization is central to BAK1 function in cell-surface receptor complexes. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005886 plasma membrane	HDA PMID:17644812 A high content in lipid-modified peripheral proteins and int...	ACCEPT	Summary: BAK1 is a single-pass plasma-membrane receptor-like kinase/co-receptor. Reason: Plasma membrane localization is central to BAK1 function in cell-surface receptor complexes. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005886 plasma membrane	IDA PMID:18182375 Proteomics studies of brassinosteroid signal transduction us...	ACCEPT	Summary: BAK1 is a single-pass plasma-membrane receptor-like kinase/co-receptor. Reason: Plasma membrane localization is central to BAK1 function in cell-surface receptor complexes. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005886 plasma membrane	IDA PMID:19616764 Regulation of cell death and innate immunity by two receptor...	ACCEPT	Summary: BAK1 is a single-pass plasma-membrane receptor-like kinase/co-receptor. Reason: Plasma membrane localization is central to BAK1 function in cell-surface receptor complexes. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005886 plasma membrane	EXP PMID:26071421 Phytosulfokine Regulates Growth in Arabidopsis through a Res...	ACCEPT	Summary: BAK1 is a single-pass plasma-membrane receptor-like kinase/co-receptor. Reason: Plasma membrane localization is central to BAK1 function in cell-surface receptor complexes. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0005886 plasma membrane	HDA PMID:28887381 Global Analysis of Membrane-associated Protein Oligomerizati...	ACCEPT	Summary: BAK1 is a single-pass plasma-membrane receptor-like kinase/co-receptor. Reason: Plasma membrane localization is central to BAK1 function in cell-surface receptor complexes. Supporting Evidence: file:ARATH/BAK1/BAK1-deep-research-falcon.md Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
GO:0010008 endosome membrane	IEA GO_REF:0000044	KEEP AS NON CORE	Summary: BAK1 receptor complexes can undergo endocytic trafficking after signaling activation. Reason: Endosome/endosome membrane localization is a supported trafficking state but secondary to the plasma membrane co-receptor role.
GO:0010008 endosome membrane	EXP PMID:15548744 Heterodimerization and endocytosis of Arabidopsis brassinost...	KEEP AS NON CORE	Summary: BAK1 receptor complexes can undergo endocytic trafficking after signaling activation. Reason: Endosome/endosome membrane localization is a supported trafficking state but secondary to the plasma membrane co-receptor role.
GO:0032991 protein-containing complex	IPI PMID:16473966 The Arabidopsis SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE1 ...	KEEP AS NON CORE	Summary: BAK1 participates in protein-containing receptor complexes with BRI1, FLS2/EFR/CERK-related receptors, and regulatory partners. Reason: The generic complex term is directionally correct but less informative than specific receptor kinase/co-receptor complex annotations.

Core Functions

Plasma-membrane LRR receptor-like Ser/Thr co-receptor kinase activity in brassinosteroid and pattern-recognition receptor complexes. BAK1/SERK3 binds ligand-activated receptors, contributes receptor-complex phosphorylation, and enables downstream growth and immune signaling.

Molecular Function:

transmembrane receptor protein serine/threonine kinase activity

Directly Involved In:

brassinosteroid mediated signaling pathway pathogen-associated molecular pattern receptor signaling pathway

Cellular Locations:

plasma membrane

Supporting Evidence:

file:ARATH/BAK1/BAK1-deep-research-falcon.md
Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.
file:interpro/panther/PTHR47988/PTHR47988-metadata.yaml
PTHR47988 is a plant LRR receptor-like serine/threonine-protein kinase family.

References

file:interpro/panther/PTHR47988/PTHR47988-entries.csv

PANTHER PTHR47988 plant LRR receptor-like serine/threonine-protein kinases family context

file:interpro/panther/PTHR47988/PTHR47988-metadata.yaml

PANTHER PTHR47988 plant LRR receptor-like serine/threonine-protein kinases family context

file:ARATH/BAK1/BAK1-deep-research-falcon.md

Falcon deep research report for Arabidopsis BAK1

Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid and immune receptor complexes.

file:ARATH/BAK1/BAK1-uniprot.txt

UniProtKB record for Arabidopsis BAK1

GO_REF:0000002

Gene Ontology annotation through association of InterPro records with GO terms

GO_REF:0000003

Gene Ontology annotation based on Enzyme Commission mapping

GO_REF:0000044

Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt

GO_REF:0000116

Automatic Gene Ontology annotation based on Rhea mapping

GO_REF:0000122

AtSubP analysis

PMID:12150928

BRI1/BAK1, a receptor kinase pair mediating brassinosteroid signaling.

PMID:12150929

BAK1, an Arabidopsis LRR receptor-like protein kinase, interacts with BRI1 and modulates brassinosteroid signaling.

PMID:14506206

Large-scale analysis of in vivo phosphorylated membrane proteins by immobilized metal ion affinity chromatography and mass spectrometry.

PMID:15548744

Heterodimerization and endocytosis of Arabidopsis brassinosteroid receptors BRI1 and AtSERK3 (BAK1).

PMID:16473966

The Arabidopsis SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE1 protein complex includes BRASSINOSTEROID-INSENSITIVE1.

PMID:16857903

Brassinosteroids regulate dissociation of BKI1, a negative regulator of BRI1 signaling, from the plasma membrane.

PMID:17583510

The BRI1-associated kinase 1, BAK1, has a brassinolide-independent role in plant cell-death control.

PMID:17625569

A flagellin-induced complex of the receptor FLS2 and BAK1 initiates plant defence.

PMID:17626179

The receptor-like kinase SERK3/BAK1 is a central regulator of innate immunity in plants.

BAK1/SERK3 is required for early PAMP-triggered immune responses and enters a flg22-dependent FLS2 receptor complex.

"In Arabidopsis thaliana, AtSERK3/BAK1 rapidly enters an elicitor-dependent complex with FLAGELLIN SENSING 2 (FLS2), the receptor for the bacterial PAMP flagellin and its peptide derivative flg22. In the absence of AtSERK3/BAK1, early flg22-dependent responses are greatly reduced."

PMID:17644812

A high content in lipid-modified peripheral proteins and integral receptor kinases features in the arabidopsis plasma membrane proteome.

PMID:18182375

Proteomics studies of brassinosteroid signal transduction using prefractionation and two-dimensional DIGE.

PMID:18667726

Arabidopsis SOMATIC EMBRYOGENESIS RECEPTOR KINASE proteins serve brassinosteroid-dependent and -independent signaling pathways.

PMID:19452453

Proteomic profiling of tandem affinity purified 14-3-3 protein complexes in Arabidopsis thaliana.

PMID:19532123

Membrane steroid-binding protein 1 (MSBP1) negatively regulates brassinosteroid signaling by enhancing the endocytosis of BAK1.

PMID:19616764

Regulation of cell death and innate immunity by two receptor-like kinases in Arabidopsis.

PMID:20018686

A receptor-like cytoplasmic kinase, BIK1, associates with a flagellin receptor complex to initiate plant innate immunity.

PMID:21499263

Stem-cell-triggered immunity through CLV3p-FLS2 signalling.

PMID:21680842

Direct ubiquitination of pattern recognition receptor FLS2 attenuates plant innate immunity.

PMID:22087006

Brassinosteroids inhibit pathogen-associated molecular pattern-triggered immune signaling independent of the receptor kinase BAK1.

PMID:22184234

Deactivation of the Arabidopsis BRASSINOSTEROID INSENSITIVE 1 (BRI1) receptor kinase by autophosphorylation within the glycine-rich loop.

PMID:22253607

Genetic evidence for an indispensable role of somatic embryogenesis receptor kinases in brassinosteroid signaling.

PMID:24114786

Structural basis for flg22-induced activation of the Arabidopsis FLS2-BAK1 immune complex.

PMID:24388849

The leucine-rich repeat receptor kinase BIR2 is a negative regulator of BAK1 in plant immunity.

PMID:24556575

Structure of the pseudokinase domain of BIR2, a regulator of BAK1-mediated immune signaling in Arabidopsis.

PMID:24625928

A bacterial tyrosine phosphatase inhibits plant pattern recognition receptor activation.

PMID:26071421

Phytosulfokine Regulates Growth in Arabidopsis through a Response Module at the Plasma Membrane That Includes CYCLIC NUCLEOTIDE-GATED CHANNEL17, H+-ATPase, and BAK1.

PMID:26308901

Allosteric receptor activation by the plant peptide hormone phytosulfokine.

PMID:26320950

Differential Function of Arabidopsis SERK Family Receptor-like Kinases in Stomatal Patterning.

PMID:27229311

Signature motif-guided identification of receptors for peptide hormones essential for root meristem growth.

PMID:27317676

The Arabidopsis Malectin-Like/LRR-RLK IOS1 Is Critical for BAK1-Dependent and BAK1-Independent Pattern-Triggered Immunity.

PMID:28887381

Global Analysis of Membrane-associated Protein Oligomerization Using Protein Correlation Profiling.

PMID:29320478

An extracellular network of Arabidopsis leucine-rich repeat receptor kinases.

PMID:30806640

Map of physical interactions between extracellular domains of Arabidopsis leucine-rich repeat receptor kinases.

PMID:32327536

STRESS INDUCED FACTOR 2 Regulates Arabidopsis Stomatal Immunity through Phosphorylation of the Anion Channel SLAC1.

PMID:33514716

Perception of a divergent family of phytocytokines by the Arabidopsis receptor kinase MIK2.

PMID:35087541

The Phloem Intercalated With Xylem-Correlated 3 Receptor-Like Kinase Constitutively Interacts With Brassinosteroid Insensitive 1-Associated Receptor Kinase 1 and Is Involved in Vascular Development in Arabidopsis.

Suggested Experiments

Experiment: Compare ligand-induced phosphoproteomes in native BAK1, kinase-dead BAK1, and receptor-specific mutant backgrounds after brassinolide and flg22 treatments.

Hypothesis: BAK1 catalytic activity produces receptor-complex-specific phosphorylation signatures in brassinosteroid and PAMP signaling.

Type: phosphoproteomics

Experiment: Use endogenous tagged BAK1 affinity purification under ligand-specific treatments followed by quantitative MS and targeted validation of receptor/RLCK partners.

Hypothesis: Different BAK1 receptor-complex partners explain the diverse generic protein-binding annotations.

Type: interaction specificity

Deep Research

Falcon

(BAK1-deep-research-falcon.md)

this with annotations you find in gene/protein databases, but these can be outdated or inaccurate. Falcon Edison Scientific Literature 35 citations 2026-05-05T07:27:05.084251

The research report should be a detailed narrative explaining the function, biological processes, and localization of the gene product. Citations should be given for all claims.

You should prioritize authoritative reviews and primary scientific literature when conducting research. You can supplement
this with annotations you find in gene/protein databases, but these can be outdated or inaccurate.

We are specifically interested in the primary function of the gene - for enzymes, what reaction is catalyzed, and what is the substrate specificity? For transporters, what is the substrate? For structural proteins or adapters, what is the broader structural role? For signaling molecules, what is the role in the pathway.

We are interested in where in or outside the cell the gene product carries out its function.

We are also interested in the signaling or biochemical pathways in which the gene functions. We are less interested in broad pleiotropic effects, except where these elucidate the precise role.

Include evidence where possible. We are interested in both experimental evidence as well as inference from structure, evolution, or bioinformatic analysis. Precise studies should be prioritized over high-throughput, where available.

Comprehensive Research Report: BAK1 / SERK3 (Arabidopsis thaliana; UniProt Q94F62; locus At4g33430)

Executive summary

BRASSINOSTEROID INSENSITIVE 1-associated receptor kinase 1 (BAK1, also SERK3) is an Arabidopsis leucine-rich repeat receptor-like kinase (LRR-RLK) that primarily acts as a shared co-receptor at the cell surface. It is recruited by multiple ligand-binding receptor kinases to form activated signaling complexes that control (i) brassinosteroid (BR) growth signaling (notably with BRI1) and (ii) pattern-triggered immunity (PTI) (notably with FLS2, EFR, and several peptide receptors). Signaling output is regulated by complex assembly, phosphorylation-dependent mechanisms, and membrane trafficking/endocytosis, and can be biased by pathway-specific alleles (e.g., bak1-5). (henning2024allostericactivationof pages 1-2, schwessinger2011phosphorylationdependentdifferentialregulation pages 1-2, yu2024characterizationofthe pages 26-29, delesalle2024thecellsurface pages 1-5)

1) Key concepts, definitions, and current understanding

1.1. What BAK1 is (verified identity)

Target identity verification (mandatory): The literature summarized here refers specifically to Arabidopsis thaliana BAK1/SERK3, a SERK-family LRR-RLK co-receptor that functions with BRI1 (BR signaling) and with immune PRRs such as EFR/FLS2 (PTI), consistent with the UniProt Q94F62 description. (henning2024allostericactivationof pages 1-2, delesalle2024thecellsurface pages 1-5, zhu2023advancesinreceptorlike pages 1-3)

1.2. RLK and co-receptor definitions

Plant receptor-like kinases (RLKs) are typically single-pass transmembrane receptors with a variable extracellular domain (ECD) for ligand perception, a transmembrane helix (TM), and a conserved cytosolic kinase domain (KD); ligand binding commonly triggers auto- and trans-phosphorylation to activate downstream signaling. (liu2024anupdateon pages 1-2, zhu2023advancesinreceptorlike pages 1-3)

Within this architecture, BAK1/SERK3 acts as a co-receptor: it generally does not provide primary ligand specificity on its own but is recruited to ligand-activated receptors to stabilize/enable receptor–co-receptor signaling complexes and phosphorylation cascades. (henning2024allostericactivationof pages 1-2, wu2024mechanisticstudyof pages 1-2, yu2024characterizationofthe pages 26-29)

1.3. Domain architecture of BAK1 (functional inference + experimental support)

BAK1 has the canonical RLK layout—extracellular LRR domain, single-pass TM, and intracellular kinase domain—as summarized in dedicated BAK1/SERK reviews. (kim2013assessingthediverse pages 1-2, liu2024anupdateon pages 1-2)

1.4. RD vs non-RD kinases (relevance to BAK1 signaling logic)

A key mechanistic distinction in BAK1 biology is that growth receptors like BRI1 are RD-type kinases, whereas prominent immune receptors like FLS2 and EFR are non-RD-type kinases with low kinase activity in vitro, implying that BAK1 often provides critical catalytic output in PTI complexes. (schwessinger2011phosphorylationdependentdifferentialregulation pages 1-2, henning2024allostericactivationof pages 1-2)

2) Functional annotation of BAK1/SERK3

2.1. Primary molecular function

BAK1 is a receptor-like protein kinase whose primary molecular role is to act as a co-receptor kinase in activated receptor complexes, enabling signal initiation and propagation via phosphorylation and (in some contexts) non-catalytic conformational mechanisms.

In BR signaling, BAK1 physically associates with BRI1 after BR perception to form the BRI1–BAK1 receptor complex required for downstream signaling. (delesalle2024thecellsurface pages 1-5, zhu2023advancesinreceptorlike pages 1-3)
In PTI, BAK1 is recruited to immune receptors such as FLS2 and EFR following ligand perception (e.g., flg22/elf18), supporting downstream MAPK, ROS, and other defense outputs. (song2024explorationofplant pages 11-14, kim2013assessingthediverse pages 3-4, greeff2012receptorlikekinasecomplexes pages 2-3)

Because BAK1 is a kinase, its “substrates” are primarily protein partners in receptor complexes and downstream cytosolic kinases; its functional specificity is largely determined by the receptor complex context rather than a small-molecule substrate. (liu2024anupdateon pages 1-2, schwessinger2011phosphorylationdependentdifferentialregulation pages 1-2)

2.2. Cellular location and trafficking

BAK1 functions at the cell surface/plasma membrane as part of receptor complexes. Upon ligand-triggered activation, RK/BAK1 complexes can undergo internalization via endocytosis (described as a step coupled to signaling initiation/attenuation). (yu2024characterizationofthe pages 26-29, delesalle2024thecellsurface pages 1-5)

2.3. Pathways and biological processes

(A) Brassinosteroid growth signaling (BRI1–BAK1 module)

A 2024 Nature Plants review reiterates that BR perception triggers formation of the BRI1–BAK1 receptor complex, which activates downstream RLCK signaling modules (e.g., BSKs/CDGs) and is embedded in plasma-membrane trafficking regulation. (delesalle2024thecellsurface pages 1-5)

(B) Pattern-triggered immunity (PRR–BAK1 module)

BAK1 is a common co-receptor for multiple immune receptors and is required for robust PTI outputs in response to MAMP/DAMP ligands perceived by receptors such as FLS2, EFR, and peptide receptors (e.g., PEPR1/2). (yu2024characterizationofthe pages 26-29, greeff2012receptorlikekinasecomplexes pages 2-3, antolinllovera2012receptorkinasesignaling pages 7-8)

A well-characterized genetic separation-of-function allele, bak1-5, is severely compromised in FLS2/EFR-mediated immune signaling while retaining BR signaling, supporting pathway-specific BAK1 regulation. (schwessinger2011phosphorylationdependentdifferentialregulation pages 1-2, kim2013assessingthediverse pages 3-4)

3) Recent developments and latest research (prioritizing 2023–2024)

3.1. 2024 eLife: Allosteric activation model in EFR–BAK1 immune signaling

Mühlenbeck et al. (eLife; July 2024; https://doi.org/10.7554/eLife.92110) provide evidence that EFR can activate BAK1 via a non-catalytic/allosteric mechanism: BAK1 phosphorylation stabilizes EFR’s active conformation, which then allosterically enhances BAK1 catalytic activity, supported by HDX-MS and suppressor mutation analysis. This work refines the canonical “reciprocal trans-phosphorylation” model for non-RD immune receptor complexes by introducing a conformational toggle logic. (henning2024allostericactivationof pages 1-2)

3.2. 2024 Nature Plants: Structure/function of MIK2–SCOOP–BAK1 complexes and N-glycan dependence

Wu et al. (Nature Plants; Nov 2024; https://doi.org/10.1038/s41477-024-01836-3) dissected how SCOOP peptides promote assembly of the immune receptor MIK2 with the co-receptor BAK1.

Key mechanistic points:
* SCOOPs use an SxS motif to bind MIK2, and C-terminal GGR residues to bridge MIK2 to BAK1, enabling ternary complex formation. (wu2024mechanisticstudyof pages 1-2)
* A surprising structural finding is that a site-specific N-glycan on MIK2 (N410) can make direct contacts with BAK1, meaning that receptor glycosylation can be a determinant of co-receptor recruitment. (wu2024mechanisticstudyof pages 1-2, wu2024mechanisticstudyof pages 8-9)

Quantitative/statistical highlights from this study (recent statistics/data):
* ITC-based affinity for AtBAK1ECD binding to AtMIK2ECD + AtSCOOP12 was Kd = 0.15 ± 0.02 µM, while the MIK2 N410D variant showed Kd = 8.12 ± 2.65 µM, i.e., a strong loss of BAK1 recruitment affinity. (wu2024mechanisticstudyof pages 8-9, wu2024mechanisticstudyof media f38c9ed2)
* Reported crystal structure resolutions for ternary complexes were 3.10 Å (AtMIK2ECD-3M–AtSCOOP12–AtBAK1ECD) and 3.30 Å (AtMIK2ECD-3M–FocSCOOPL–AtBAK1ECD). (wu2024mechanisticstudyof media f38c9ed2, wu2024mechanisticstudyof media f614bf57)
* Functional assays included defined ligand treatments (e.g., ROS assays using 0.5 µM AtSCOOP12; MAPK activation assay using 0.4 µM flg22 for 10 min) and a root-growth assay sample size reported as n = 51. (wu2024mechanisticstudyof pages 25-35, wu2024mechanisticstudyof pages 17-25)

Conservation across species:
* The N-glycan-mediated heterodimerization logic is reported to occur in both Arabidopsis and Brassica napus, underscoring cross-species relevance of BAK1 recruitment rules. (wu2024mechanisticstudyof pages 1-2)

3.3. 2024 Nature Plants review: cell-surface organization and trafficking in BR signaling

Delesalle et al. (Nature Plants; Feb 2024; https://doi.org/10.1038/s41477-024-01621-2) review BR perception as a cell-surface process centered on BRI1–BAK1 complex formation and emphasize the role of plasma membrane and endomembrane trafficking routes in tuning receptor abundance and signaling duration. (delesalle2024thecellsurface pages 1-5, delesalle2024thecellsurface pages 20-24)

3.4. 2023–2024 reviews: RLK architecture and growth–stress balancing

Recent reviews reiterate the general RLK definition (ECD–TM–KD), phosphorylation-based activation, and the frequent requirement of a co-receptor for full signaling competence—providing updated conceptual framing for BAK1 function as a shared co-receptor hub. (liu2024anupdateon pages 1-2, zhu2023advancesinreceptorlike pages 1-3)

4) Current applications and real-world implementations

4.1. Engineering crop immunity via PRR/co-receptor modules

A major translational direction is the use of pattern-recognition receptors (PRRs) as tools to engineer crop immunity, for which BAK1/SERK co-receptor availability/compatibility is a key design constraint because many PRRs signal through BAK1-containing complexes. (song2024explorationofplant pages 11-14, yu2024characterizationofthe pages 26-29)

More generally, recent RLK-focused reviews highlight engineering tactics such as chimeric receptor construction, domain swapping, and manipulation of co-receptor modules (SERKs/BAK1 family) to tune growth and stress responses in crops. (zhu2023advancesinreceptorlike pages 15-16, zhu2023advancesinreceptorlike pages 17-18)

4.2. BR pathway manipulation for agronomic traits (yield vs defense tradeoff)

The BR pathway (in which BAK1 is a core co-receptor) is a practical lever for yield and architecture; a 2024 Nature Plants review cites a 2023 wheat report in which reducing brassinosteroid signaling enhanced grain yield in semi-dwarf wheat, illustrating real-world relevance of BR signaling manipulation. (delesalle2024thecellsurface pages 20-24)

4.3. Mechanism-informed engineering opportunities from 2024 structural work

The MIK2–SCOOP–BAK1 study implies that engineering receptor glycosylation sites or ligand motifs could be used to tune co-receptor recruitment and immune output, including potentially across Brassicaceae species where the mechanism appears conserved. (wu2024mechanisticstudyof pages 1-2)

5) Expert opinions and analysis (authoritative sources)

5.1. BAK1 as a central hub at the cell surface

A recurring theme across authoritative sources is that BAK1 is not a single-pathway receptor but a shared co-receptor hub used by many RLKs in growth and immunity. This hub role creates both opportunity (broad leverage) and risk (pleiotropy and growth–defense tradeoffs) when BAK1-associated signaling is engineered. (yu2024characterizationofthe pages 26-29, liu2024anupdateon pages 1-2)

5.2. Signal specificity and pathway separation

Pathway-specific outcomes can arise from differential phosphorylation logic and complex composition; classic genetic evidence (bak1-5) demonstrates that immune signaling can be selectively impaired without abolishing BR signaling, indicating separable mechanistic requirements in different BAK1-dependent complexes. (schwessinger2011phosphorylationdependentdifferentialregulation pages 1-2, kim2013assessingthediverse pages 3-4)

5.3. Updated mechanistic perspective (2024)

Recent mechanistic research suggests BAK1 activation in immune complexes may not be adequately explained by “simple reciprocal transphosphorylation,” as exemplified by the proposed allosteric activation mechanism in EFR–BAK1 signaling (HDX-MS supported). (henning2024allostericactivationof pages 1-2)

Evidence summary table

The following table provides a compact annotation summary across domains, localization, pathway roles, quantitative data, and applications.

Aspect	Key points	Representative recent sources (with year)	Notes/quantitative details
Identity	Arabidopsis BAK1 = SERK3 = AtBAK1 = At4g33430, a SERK-family leucine-rich repeat receptor-like kinase (LRR-RLK) that acts mainly as a shared co-receptor for ligand-binding receptor kinases in growth and immunity. It matches the UniProt Q94F62 description of a membrane receptor kinase with BR and immune functions. (henning2024allostericactivationof pages 1-2, liu2024anupdateon pages 1-2, zhu2023advancesinreceptorlike pages 1-3)	Delesalle et al., 2024; Liu et al., 2024; Zhu et al., 2023	Recent sources explicitly connect BAK1/SERK3 with BRI1, FLS2, EFR and other PRRs; older literature established AtSERK3 identity as BAK1. (henning2024allostericactivationof pages 1-2, delesalle2024thecellsurface pages 1-5)
Domain architecture	BAK1 has the canonical plant RLK layout: extracellular LRR ectodomain, single-pass transmembrane helix, and intracellular kinase domain. SERK-family proteins are short-LRR co-receptors rather than primary ligand-binding receptors in many pathways. (kim2013assessingthediverse pages 1-2, liu2024anupdateon pages 1-2, zhu2023advancesinreceptorlike pages 1-3)	Liu et al., 2024; Zhu et al., 2023	Reviews describe RLKs generally as ECD-TM-KD proteins; BAK1-specific reviews identify it as a SERK/LRR-RLK co-receptor. (kim2013assessingthediverse pages 1-2, liu2024anupdateon pages 1-2)
Localization	BAK1 functions at the cell surface/plasma membrane in receptor complexes and can undergo or accompany ligand-triggered internalization/endocytosis with activated receptor complexes. (yu2024characterizationofthe pages 26-29, delesalle2024thecellsurface pages 1-5)	Delesalle et al., 2024; Yu, 2024	BRI1/BAK1 signaling is tightly linked to membrane trafficking; receptor internalization routes are emphasized in recent BR reviews, and BAK1-containing activated complexes are described as internalized after signaling. (yu2024characterizationofthe pages 26-29, delesalle2024thecellsurface pages 1-5)
Core pathways	The two best-established functional pathways are brassinosteroid (BR) signaling with BRI1 and pattern-triggered immunity (PTI) with receptors such as FLS2, EFR, and PEPR1/2. BAK1 also contributes to cell-death control and other receptor pathways. (henning2024allostericactivationof pages 1-2, kim2013assessingthediverse pages 3-4, yu2024characterizationofthe pages 26-29)	Henning et al., 2024; Kim et al., 2013; Yu, 2024	In BR signaling, BAK1 promotes BRI1 activation and downstream BR signaling; in PTI it is recruited to immune receptors after elicitor perception. (henning2024allostericactivationof pages 1-2, kim2013assessingthediverse pages 3-4)
Interaction partners	Supported partners include BRI1, FLS2, EFR, PEPR1/2, MIK2, PXL1, SOBIR1-associated RLP complexes, BIK1, and negative regulators such as BIR proteins. (song2024explorationofplant pages 11-14, wu2024mechanisticstudyof pages 1-2, yu2024characterizationofthe pages 26-29, greeff2012receptorlikekinasecomplexes pages 2-3)	Wu et al., 2024; Yu, 2024; Greeff et al., 2012	BAK1 is a signaling hub rather than a dedicated receptor. BIK1 is a prominent downstream RLCK; SOBIR1 supplies kinase activity for RLPs that then recruit BAK1. (song2024explorationofplant pages 11-14, yu2024characterizationofthe pages 26-29, greeff2012receptorlikekinasecomplexes pages 2-3)
Regulatory mechanisms	BAK1 signaling is controlled by ligand-induced heterodimerization, transphosphorylation/autophosphorylation, pathway-specific phosphorylation outputs, endocytosis, and negative regulation by BIR proteins. Distinct alleles can uncouple BR and immune outputs. (schwessinger2011phosphorylationdependentdifferentialregulation pages 1-2, kim2013assessingthediverse pages 5-6, yu2024characterizationofthe pages 26-29)	Schwessinger et al., 2011; Yu, 2024; Kim et al., 2013	The bak1-5 allele strongly compromises FLS2/EFR-mediated PTI while leaving BR signaling largely intact, showing pathway specificity. BAK1/BKK1 redundancy is important in growth and cell-death control. (schwessinger2011phosphorylationdependentdifferentialregulation pages 1-2, antolinllovera2012receptorkinasesignaling pages 7-8)
Key 2023-2024 advances	2024 work showed allosteric activation of BAK1 by EFR, revising the simple reciprocal-transphosphorylation model for non-RD immune receptors. Another 2024 study showed SCOOP–MIK2–BAK1 complex assembly depends on peptide SxS and C-terminal GGR motifs plus site-specific N-glycan-mediated contacts between MIK2 and BAK1. BR-focused 2024 studies further emphasized cell-surface organization and SERK-assisted BR complex formation. (henning2024allostericactivationof pages 1-2, wu2024mechanisticstudyof pages 1-2, delesalle2024thecellsurface pages 1-5)	Henning et al., 2024; Wu et al., 2024; Delesalle et al., 2024	The EFR study supports a conformational toggle/allosteric model; the MIK2 study identifies direct glycan contributions to receptor–co-receptor binding and signaling competence. (henning2024allostericactivationof pages 1-2, wu2024mechanisticstudyof pages 1-2)
Quantitative data	In the AtMIK2ECD + AtSCOOP12 + AtBAK1ECD system, ITC reported Kd = 0.15 ± 0.02 µM for wild type versus 8.12 ± 2.65 µM for the AtMIK2 N410D glycan-site mutant, indicating a strong loss of BAK1 recruitment. Crystal structure resolutions for ternary complexes were reported at 3.10 Å and 3.30 Å. Root-growth assays for SCOOPL variants included n = 51; some ROS/MAPK assays used 0.5 µM AtSCOOP12 and 0.4 µM flg22 for 10 min. (wu2024mechanisticstudyof pages 8-9, wu2024mechanisticstudyof pages 25-35, wu2024mechanisticstudyof pages 17-25, wu2024mechanisticstudyof media f38c9ed2)	Wu et al., 2024	The MIK2 N-glycan at N410 contacts BAK1 residues D50/T52; loss of that glycan reduced affinity by >50-fold and abolished SCOOP-triggered immune outputs. (wu2024mechanisticstudyof pages 8-9, wu2024mechanisticstudyof media f38c9ed2)
Applications	BAK1 biology is relevant to engineering crop immunity and managing growth–defense tradeoffs. Practical strategies supported by recent reviews include PRR transfer/stacking with compatible SERK/BAK1 co-receptors, tuning co-receptor recruitment, and manipulating BR pathway strength to optimize agronomic traits. (zhu2023advancesinreceptorlike pages 15-16, delesalle2024thecellsurface pages 20-24, zhu2023advancesinreceptorlike pages 17-18, li2010multitaskingofsomatic pages 6-6)	Zhu et al., 2023; Delesalle et al., 2024	Crop-relevant examples in recent literature include manipulating RLK/SERK modules and a cited 2023 wheat study showing that reducing BR signaling enhanced grain yield. Mechanistic BAK1 insights also suggest engineering receptor/co-receptor compatibility across species. (wu2024mechanisticstudyof pages 1-2, delesalle2024thecellsurface pages 20-24)

Table: This table summarizes the evidence-supported functional annotation of Arabidopsis BAK1/SERK3 (UniProt Q94F62), including identity, mechanism, pathway roles, recent advances, and quantitative findings. It is useful as a compact reference for building the full research report with citations.

Image-based evidence (quantitative structural data)

Wu et al. (Nature Plants 2024) present ITC measurements and structural-resolution data supporting the importance of MIK2 glycosylation for BAK1 recruitment. The cropped figure/table region includes the Kd values (0.15 ± 0.02 µM vs 8.12 ± 2.65 µM) and ternary complex resolutions (3.10 Å, 3.30 Å). (wu2024mechanisticstudyof media f38c9ed2, wu2024mechanisticstudyof media f614bf57)

Limitations of this report (scope and evidence availability)

Some historically foundational primary papers that originally defined BAK1 (e.g., early 2002 co-receptor discovery) were not directly retrieved as full text in the current tool context; however, the identity and core functions are corroborated by multiple high-quality later sources and recent reviews. (delesalle2024thecellsurface pages 1-5, zhu2023advancesinreceptorlike pages 1-3)
Not all pathway branches mediated by SERK family members were exhaustively covered; the focus here is on the primary, best-supported roles of BAK1/SERK3 in BR signaling and PTI, and on 2023–2024 mechanistic updates most directly relevant to BAK1 recruitment/activation. (henning2024allostericactivationof pages 1-2, wu2024mechanisticstudyof pages 1-2)

References

(henning2024allostericactivationof pages 1-2): Henning Mühlenbeck, Yuko Tsutsui, Mark A Lemmon, Kyle W Bender, and Cyril Zipfel. Allosteric activation of the co-receptor bak1 by the efr receptor kinase initiates immune signaling. eLife, Jul 2024. URL: https://doi.org/10.7554/elife.92110, doi:10.7554/elife.92110. This article has 30 citations and is from a domain leading peer-reviewed journal.
(schwessinger2011phosphorylationdependentdifferentialregulation pages 1-2): Benjamin Schwessinger, Milena Roux, Yasuhiro Kadota, Vardis Ntoukakis, Jan Sklenar, Alexandra Jones, and Cyril Zipfel. Phosphorylation-dependent differential regulation of plant growth, cell death, and innate immunity by the regulatory receptor-like kinase bak1. PLoS Genetics, 7:e1002046, Apr 2011. URL: https://doi.org/10.1371/journal.pgen.1002046, doi:10.1371/journal.pgen.1002046. This article has 623 citations and is from a domain leading peer-reviewed journal.
(yu2024characterizationofthe pages 26-29): Liping Yu. Characterization of the role of csa1 in maintaining homeostasis of bak1-bir3 complexes and triggering autoimmune cell death. Unknown, Mar 2024. URL: https://doi.org/10.15496/publikation-93018, doi:10.15496/publikation-93018. This article has 0 citations.
(delesalle2024thecellsurface pages 1-5): Charlotte Delesalle, Grégory Vert, and Satoshi Fujita. The cell surface is the place to be for brassinosteroid perception and responses. Nature Plants, 10:206-218, Feb 2024. URL: https://doi.org/10.1038/s41477-024-01621-2, doi:10.1038/s41477-024-01621-2. This article has 19 citations and is from a highest quality peer-reviewed journal.
(zhu2023advancesinreceptorlike pages 1-3): Qingfeng Zhu, Yanzhao Feng, Jiao Xue, Pei Chen, Aixia Zhang, and Yang Yu. Advances in receptor-like protein kinases in balancing plant growth and stress responses. Plants, 12:427, Jan 2023. URL: https://doi.org/10.3390/plants12030427, doi:10.3390/plants12030427. This article has 55 citations.
(liu2024anupdateon pages 1-2): Jing Liu, Wenjuan Li, Guang Wu, and Khawar Ali. An update on evolutionary, structural, and functional studies of receptor-like kinases in plants. Frontiers in Plant Science, Jan 2024. URL: https://doi.org/10.3389/fpls.2024.1305599, doi:10.3389/fpls.2024.1305599. This article has 50 citations.
(wu2024mechanisticstudyof pages 1-2): Huimin Wu, Lihao Wan, Zunyong Liu, Yunqing Jian, Chenchen Zhang, Xiakun Mao, Zhiyun Wang, Qiang Wang, Yaxin Hu, Lizhong Xiong, Zhujun Xia, Juan Xue, Shan Li, Ping He, Libo Shan, and Shutong Xu. Mechanistic study of scoops recognition by mik2–bak1 complex reveals the role of n-glycans in plant ligand–receptor–coreceptor complex formation. Nature Plants, 10:1984-1998, Nov 2024. URL: https://doi.org/10.1038/s41477-024-01836-3, doi:10.1038/s41477-024-01836-3. This article has 31 citations and is from a highest quality peer-reviewed journal.
(kim2013assessingthediverse pages 1-2): Beg Hab Kim, Sun Young Kim, and Kyoung Hee Nam. Assessing the diverse functions of bak1 and its homologs in arabidopsis, beyond br signaling and pti responses. Molecules and Cells, 35:7-16, Jan 2013. URL: https://doi.org/10.1007/s10059-013-2255-3, doi:10.1007/s10059-013-2255-3. This article has 56 citations and is from a peer-reviewed journal.
(song2024explorationofplant pages 11-14): Yanyue Song. Exploration of plant recognition receptors as tools to engineer crop immunity. Unknown, Sep 2024. URL: https://doi.org/10.15496/publikation-99005, doi:10.15496/publikation-99005. This article has 1 citations.
(kim2013assessingthediverse pages 3-4): Beg Hab Kim, Sun Young Kim, and Kyoung Hee Nam. Assessing the diverse functions of bak1 and its homologs in arabidopsis, beyond br signaling and pti responses. Molecules and Cells, 35:7-16, Jan 2013. URL: https://doi.org/10.1007/s10059-013-2255-3, doi:10.1007/s10059-013-2255-3. This article has 56 citations and is from a peer-reviewed journal.
(greeff2012receptorlikekinasecomplexes pages 2-3): Christiaan Greeff, Milena Roux, John Mundy, and Morten Petersen. Receptor-like kinase complexes in plant innate immunity. Frontiers in Plant Science, Aug 2012. URL: https://doi.org/10.3389/fpls.2012.00209, doi:10.3389/fpls.2012.00209. This article has 139 citations.
(antolinllovera2012receptorkinasesignaling pages 7-8): Meritxell Antolín-Llovera, Martina K. Ried, Andreas Binder, and Martin Parniske. Receptor kinase signaling pathways in plant-microbe interactions. Annual review of phytopathology, 50:451-73, Sep 2012. URL: https://doi.org/10.1146/annurev-phyto-081211-173002, doi:10.1146/annurev-phyto-081211-173002. This article has 245 citations and is from a domain leading peer-reviewed journal.
(wu2024mechanisticstudyof pages 8-9): Huimin Wu, Lihao Wan, Zunyong Liu, Yunqing Jian, Chenchen Zhang, Xiakun Mao, Zhiyun Wang, Qiang Wang, Yaxin Hu, Lizhong Xiong, Zhujun Xia, Juan Xue, Shan Li, Ping He, Libo Shan, and Shutong Xu. Mechanistic study of scoops recognition by mik2–bak1 complex reveals the role of n-glycans in plant ligand–receptor–coreceptor complex formation. Nature Plants, 10:1984-1998, Nov 2024. URL: https://doi.org/10.1038/s41477-024-01836-3, doi:10.1038/s41477-024-01836-3. This article has 31 citations and is from a highest quality peer-reviewed journal.
(wu2024mechanisticstudyof media f38c9ed2): Huimin Wu, Lihao Wan, Zunyong Liu, Yunqing Jian, Chenchen Zhang, Xiakun Mao, Zhiyun Wang, Qiang Wang, Yaxin Hu, Lizhong Xiong, Zhujun Xia, Juan Xue, Shan Li, Ping He, Libo Shan, and Shutong Xu. Mechanistic study of scoops recognition by mik2–bak1 complex reveals the role of n-glycans in plant ligand–receptor–coreceptor complex formation. Nature Plants, 10:1984-1998, Nov 2024. URL: https://doi.org/10.1038/s41477-024-01836-3, doi:10.1038/s41477-024-01836-3. This article has 31 citations and is from a highest quality peer-reviewed journal.
(wu2024mechanisticstudyof media f614bf57): Huimin Wu, Lihao Wan, Zunyong Liu, Yunqing Jian, Chenchen Zhang, Xiakun Mao, Zhiyun Wang, Qiang Wang, Yaxin Hu, Lizhong Xiong, Zhujun Xia, Juan Xue, Shan Li, Ping He, Libo Shan, and Shutong Xu. Mechanistic study of scoops recognition by mik2–bak1 complex reveals the role of n-glycans in plant ligand–receptor–coreceptor complex formation. Nature Plants, 10:1984-1998, Nov 2024. URL: https://doi.org/10.1038/s41477-024-01836-3, doi:10.1038/s41477-024-01836-3. This article has 31 citations and is from a highest quality peer-reviewed journal.
(wu2024mechanisticstudyof pages 25-35): Huimin Wu, Lihao Wan, Zunyong Liu, Yunqing Jian, Chenchen Zhang, Xiakun Mao, Zhiyun Wang, Qiang Wang, Yaxin Hu, Lizhong Xiong, Zhujun Xia, Juan Xue, Shan Li, Ping He, Libo Shan, and Shutong Xu. Mechanistic study of scoops recognition by mik2–bak1 complex reveals the role of n-glycans in plant ligand–receptor–coreceptor complex formation. Nature Plants, 10:1984-1998, Nov 2024. URL: https://doi.org/10.1038/s41477-024-01836-3, doi:10.1038/s41477-024-01836-3. This article has 31 citations and is from a highest quality peer-reviewed journal.
(wu2024mechanisticstudyof pages 17-25): Huimin Wu, Lihao Wan, Zunyong Liu, Yunqing Jian, Chenchen Zhang, Xiakun Mao, Zhiyun Wang, Qiang Wang, Yaxin Hu, Lizhong Xiong, Zhujun Xia, Juan Xue, Shan Li, Ping He, Libo Shan, and Shutong Xu. Mechanistic study of scoops recognition by mik2–bak1 complex reveals the role of n-glycans in plant ligand–receptor–coreceptor complex formation. Nature Plants, 10:1984-1998, Nov 2024. URL: https://doi.org/10.1038/s41477-024-01836-3, doi:10.1038/s41477-024-01836-3. This article has 31 citations and is from a highest quality peer-reviewed journal.
(delesalle2024thecellsurface pages 20-24): Charlotte Delesalle, Grégory Vert, and Satoshi Fujita. The cell surface is the place to be for brassinosteroid perception and responses. Nature Plants, 10:206-218, Feb 2024. URL: https://doi.org/10.1038/s41477-024-01621-2, doi:10.1038/s41477-024-01621-2. This article has 19 citations and is from a highest quality peer-reviewed journal.
(zhu2023advancesinreceptorlike pages 15-16): Qingfeng Zhu, Yanzhao Feng, Jiao Xue, Pei Chen, Aixia Zhang, and Yang Yu. Advances in receptor-like protein kinases in balancing plant growth and stress responses. Plants, 12:427, Jan 2023. URL: https://doi.org/10.3390/plants12030427, doi:10.3390/plants12030427. This article has 55 citations.
(zhu2023advancesinreceptorlike pages 17-18): Qingfeng Zhu, Yanzhao Feng, Jiao Xue, Pei Chen, Aixia Zhang, and Yang Yu. Advances in receptor-like protein kinases in balancing plant growth and stress responses. Plants, 12:427, Jan 2023. URL: https://doi.org/10.3390/plants12030427, doi:10.3390/plants12030427. This article has 55 citations.
(kim2013assessingthediverse pages 5-6): Beg Hab Kim, Sun Young Kim, and Kyoung Hee Nam. Assessing the diverse functions of bak1 and its homologs in arabidopsis, beyond br signaling and pti responses. Molecules and Cells, 35:7-16, Jan 2013. URL: https://doi.org/10.1007/s10059-013-2255-3, doi:10.1007/s10059-013-2255-3. This article has 56 citations and is from a peer-reviewed journal.
(li2010multitaskingofsomatic pages 6-6): Jia Li. Multi-tasking of somatic embryogenesis receptor-like protein kinases. Current opinion in plant biology, 13 5:509-14, Oct 2010. URL: https://doi.org/10.1016/j.pbi.2010.09.004, doi:10.1016/j.pbi.2010.09.004. This article has 149 citations and is from a peer-reviewed journal.

Citations

delesalle2024thecellsurface pages 1-5
henning2024allostericactivationof pages 1-2
wu2024mechanisticstudyof pages 1-2
delesalle2024thecellsurface pages 20-24
schwessinger2011phosphorylationdependentdifferentialregulation pages 1-2
yu2024characterizationofthe pages 26-29
zhu2023advancesinreceptorlike pages 1-3
liu2024anupdateon pages 1-2
kim2013assessingthediverse pages 1-2
song2024explorationofplant pages 11-14
kim2013assessingthediverse pages 3-4
greeff2012receptorlikekinasecomplexes pages 2-3
antolinllovera2012receptorkinasesignaling pages 7-8
wu2024mechanisticstudyof pages 8-9
wu2024mechanisticstudyof pages 25-35
wu2024mechanisticstudyof pages 17-25
zhu2023advancesinreceptorlike pages 15-16
zhu2023advancesinreceptorlike pages 17-18
kim2013assessingthediverse pages 5-6
li2010multitaskingofsomatic pages 6-6
https://doi.org/10.7554/eLife.92110
https://doi.org/10.1038/s41477-024-01836-3
https://doi.org/10.1038/s41477-024-01621-2
https://doi.org/10.7554/elife.92110,
https://doi.org/10.1371/journal.pgen.1002046,
https://doi.org/10.15496/publikation-93018,
https://doi.org/10.1038/s41477-024-01621-2,
https://doi.org/10.3390/plants12030427,
https://doi.org/10.3389/fpls.2024.1305599,
https://doi.org/10.1038/s41477-024-01836-3,
https://doi.org/10.1007/s10059-013-2255-3,
https://doi.org/10.15496/publikation-99005,
https://doi.org/10.3389/fpls.2012.00209,
https://doi.org/10.1146/annurev-phyto-081211-173002,
https://doi.org/10.1016/j.pbi.2010.09.004,

📄 View Raw YAML

id: Q94F62
gene_symbol: BAK1
product_type: PROTEIN
status: COMPLETE
taxon:
  id: NCBITaxon:3702
  label: Arabidopsis thaliana
description: BAK1/SERK3 is an Arabidopsis plasma-membrane leucine-rich repeat receptor-like kinase that
  acts mainly as a co-receptor kinase. It forms ligand-induced receptor complexes with brassinosteroid
  receptor BRI1 and multiple pattern-recognition receptors such as FLS2/EFR/CERK-related immune complexes,
  then contributes kinase activity and scaffold/co-receptor functions needed for brassinosteroid signaling,
  pattern-triggered immunity, receptor complex phosphorylation, endocytosis, and signaling attenuation.
  BAK1 also participates in cell-death regulation, but broad pathogen-defense phenotypes are downstream
  outputs of its receptor-complex role rather than separate core functions.
existing_annotations:
- term:
    id: GO:0140426
    label: pathogen-associated molecular pattern receptor signaling pathway
  evidence_type: IMP
  original_reference_id: PMID:17626179
  review:
    summary: BAK1/SERK3 functions as a co-receptor kinase in FLS2/EFR/CERK-family pattern-recognition
      receptor complexes.
    action: NEW
    reason: PMID:17626179 shows that loss of SERK3/BAK1 reduces early flg22-dependent
      responses and that BAK1 rapidly enters a ligand-dependent complex with FLS2, directly supporting
      IMP curation to the PAMP receptor signaling pathway.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
    - reference_id: PMID:17626179
      supporting_text: >-
        AtSERK3/BAK1 rapidly enters an elicitor-dependent complex with
        FLAGELLIN SENSING 2 (FLS2), the receptor for the bacterial PAMP
        flagellin and its peptide derivative flg22.
- term:
    id: GO:0002229
    label: defense response to oomycetes
  evidence_type: IMP
  original_reference_id: PMID:17583510
  review:
    summary: BAK1 contributes to defense response to oomycetes through pattern-recognition receptor and
      cell-death signaling complexes.
    action: KEEP_AS_NON_CORE
    reason: The phenotype/process is supported as a downstream immune output, but BAK1's core role is
      receptor-like kinase co-receptor signaling rather than being a pathogen-response effector itself.
- term:
    id: GO:0009626
    label: plant-type hypersensitive response
  evidence_type: IMP
  original_reference_id: PMID:18667726
  review:
    summary: BAK1 contributes to plant-type hypersensitive response through pattern-recognition receptor
      and cell-death signaling complexes.
    action: KEEP_AS_NON_CORE
    reason: The phenotype/process is supported as a downstream immune output, but BAK1's core role is
      receptor-like kinase co-receptor signaling rather than being a pathogen-response effector itself.
- term:
    id: GO:0009742
    label: brassinosteroid mediated signaling pathway
  evidence_type: IMP
  original_reference_id: PMID:18667726
  review:
    summary: BAK1/SERK3 is a BRI1-associated co-receptor kinase required for normal brassinosteroid signaling
      outputs.
    action: ACCEPT
    reason: Brassinosteroid receptor-complex signaling is one of the two best-supported core biological
      roles of BAK1.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0009742
    label: brassinosteroid mediated signaling pathway
  evidence_type: IGI
  original_reference_id: PMID:22253607
  review:
    summary: BAK1/SERK3 is a BRI1-associated co-receptor kinase required for normal brassinosteroid signaling
      outputs.
    action: ACCEPT
    reason: Brassinosteroid receptor-complex signaling is one of the two best-supported core biological
      roles of BAK1.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0042742
    label: defense response to bacterium
  evidence_type: IMP
  original_reference_id: PMID:17583510
  review:
    summary: BAK1 contributes to defense response to bacterium through pattern-recognition receptor and
      cell-death signaling complexes.
    action: KEEP_AS_NON_CORE
    reason: The phenotype/process is supported as a downstream immune output, but BAK1's core role is
      receptor-like kinase co-receptor signaling rather than being a pathogen-response effector itself.
- term:
    id: GO:0050832
    label: defense response to fungus
  evidence_type: IMP
  original_reference_id: PMID:17583510
  review:
    summary: BAK1 contributes to defense response to fungus through pattern-recognition receptor and cell-death
      signaling complexes.
    action: KEEP_AS_NON_CORE
    reason: The phenotype/process is supported as a downstream immune output, but BAK1's core role is
      receptor-like kinase co-receptor signaling rather than being a pathogen-response effector itself.
- term:
    id: GO:0004672
    label: protein kinase activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  review:
    summary: BAK1 has catalytic activity as a membrane receptor-like Ser/Thr kinase, but protein kinase
      activity is less precise for this protein.
    action: MODIFY
    reason: The transmembrane receptor protein serine/threonine kinase activity term captures both the
      catalytic activity and receptor-like membrane context.
    proposed_replacement_terms:
    - id: GO:0004675
      label: transmembrane receptor protein serine/threonine kinase activity
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0004672
    label: protein kinase activity
  evidence_type: IDA
  original_reference_id: PMID:21680842
  review:
    summary: BAK1 has catalytic activity as a membrane receptor-like Ser/Thr kinase, but protein kinase
      activity is less precise for this protein.
    action: MODIFY
    reason: The transmembrane receptor protein serine/threonine kinase activity term captures both the
      catalytic activity and receptor-like membrane context.
    proposed_replacement_terms:
    - id: GO:0004675
      label: transmembrane receptor protein serine/threonine kinase activity
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0004674
    label: protein serine/threonine kinase activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000003
  review:
    summary: BAK1 has catalytic activity as a membrane receptor-like Ser/Thr kinase, but protein serine/threonine
      kinase activity is less precise for this protein.
    action: MODIFY
    reason: The transmembrane receptor protein serine/threonine kinase activity term captures both the
      catalytic activity and receptor-like membrane context.
    proposed_replacement_terms:
    - id: GO:0004675
      label: transmembrane receptor protein serine/threonine kinase activity
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0004674
    label: protein serine/threonine kinase activity
  evidence_type: IDA
  original_reference_id: PMID:12150929
  review:
    summary: BAK1 has catalytic activity as a membrane receptor-like Ser/Thr kinase, but protein serine/threonine
      kinase activity is less precise for this protein.
    action: MODIFY
    reason: The transmembrane receptor protein serine/threonine kinase activity term captures both the
      catalytic activity and receptor-like membrane context.
    proposed_replacement_terms:
    - id: GO:0004675
      label: transmembrane receptor protein serine/threonine kinase activity
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0004713
    label: protein tyrosine kinase activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000116
  review:
    summary: BAK1 has catalytic activity as a membrane receptor-like Ser/Thr kinase, but protein tyrosine
      kinase activity is less precise for this protein.
    action: MODIFY
    reason: The transmembrane receptor protein serine/threonine kinase activity term captures both the
      catalytic activity and receptor-like membrane context.
    proposed_replacement_terms:
    - id: GO:0004675
      label: transmembrane receptor protein serine/threonine kinase activity
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0004714
    label: transmembrane receptor protein tyrosine kinase activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000003
  review:
    summary: BAK1 has catalytic activity as a membrane receptor-like Ser/Thr kinase, but transmembrane
      receptor protein tyrosine kinase activity is less precise for this protein.
    action: MODIFY
    reason: The transmembrane receptor protein serine/threonine kinase activity term captures both the
      catalytic activity and receptor-like membrane context.
    proposed_replacement_terms:
    - id: GO:0004675
      label: transmembrane receptor protein serine/threonine kinase activity
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005102
    label: signaling receptor binding
  evidence_type: IPI
  original_reference_id: PMID:26320950
  review:
    summary: BAK1 binds ligand-activated receptors such as BIR-regulated LRR-RLK complexes as a signaling
      co-receptor.
    action: ACCEPT
    reason: Signaling receptor binding is a specific molecular role for BAK1 as an LRR-RLK co-receptor.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:12150928
  review:
    summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex
      context.
    action: MARK_AS_OVER_ANNOTATED
    reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation
      is receptor kinase/co-receptor complex binding and signaling.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:12150929
  review:
    summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex
      context.
    action: MARK_AS_OVER_ANNOTATED
    reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation
      is receptor kinase/co-receptor complex binding and signaling.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:15548744
  review:
    summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex
      context.
    action: MARK_AS_OVER_ANNOTATED
    reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation
      is receptor kinase/co-receptor complex binding and signaling.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:16473966
  review:
    summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex
      context.
    action: MARK_AS_OVER_ANNOTATED
    reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation
      is receptor kinase/co-receptor complex binding and signaling.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:16857903
  review:
    summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex
      context.
    action: MARK_AS_OVER_ANNOTATED
    reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation
      is receptor kinase/co-receptor complex binding and signaling.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:17625569
  review:
    summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex
      context.
    action: MARK_AS_OVER_ANNOTATED
    reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation
      is receptor kinase/co-receptor complex binding and signaling.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:17626179
  review:
    summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex
      context.
    action: MARK_AS_OVER_ANNOTATED
    reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation
      is receptor kinase/co-receptor complex binding and signaling.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:19452453
  review:
    summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex
      context.
    action: MARK_AS_OVER_ANNOTATED
    reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation
      is receptor kinase/co-receptor complex binding and signaling.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:19532123
  review:
    summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex
      context.
    action: MARK_AS_OVER_ANNOTATED
    reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation
      is receptor kinase/co-receptor complex binding and signaling.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:19616764
  review:
    summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex
      context.
    action: MARK_AS_OVER_ANNOTATED
    reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation
      is receptor kinase/co-receptor complex binding and signaling.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:20018686
  review:
    summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex
      context.
    action: MARK_AS_OVER_ANNOTATED
    reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation
      is receptor kinase/co-receptor complex binding and signaling.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:21499263
  review:
    summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex
      context.
    action: MARK_AS_OVER_ANNOTATED
    reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation
      is receptor kinase/co-receptor complex binding and signaling.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:22087006
  review:
    summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex
      context.
    action: MARK_AS_OVER_ANNOTATED
    reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation
      is receptor kinase/co-receptor complex binding and signaling.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:22184234
  review:
    summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex
      context.
    action: MARK_AS_OVER_ANNOTATED
    reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation
      is receptor kinase/co-receptor complex binding and signaling.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:24114786
  review:
    summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex
      context.
    action: MARK_AS_OVER_ANNOTATED
    reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation
      is receptor kinase/co-receptor complex binding and signaling.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:24388849
  review:
    summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex
      context.
    action: MARK_AS_OVER_ANNOTATED
    reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation
      is receptor kinase/co-receptor complex binding and signaling.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:24556575
  review:
    summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex
      context.
    action: MARK_AS_OVER_ANNOTATED
    reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation
      is receptor kinase/co-receptor complex binding and signaling.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:24625928
  review:
    summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex
      context.
    action: MARK_AS_OVER_ANNOTATED
    reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation
      is receptor kinase/co-receptor complex binding and signaling.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:26308901
  review:
    summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex
      context.
    action: MARK_AS_OVER_ANNOTATED
    reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation
      is receptor kinase/co-receptor complex binding and signaling.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:27229311
  review:
    summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex
      context.
    action: MARK_AS_OVER_ANNOTATED
    reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation
      is receptor kinase/co-receptor complex binding and signaling.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:27317676
  review:
    summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex
      context.
    action: MARK_AS_OVER_ANNOTATED
    reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation
      is receptor kinase/co-receptor complex binding and signaling.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:29320478
  review:
    summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex
      context.
    action: MARK_AS_OVER_ANNOTATED
    reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation
      is receptor kinase/co-receptor complex binding and signaling.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:30806640
  review:
    summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex
      context.
    action: MARK_AS_OVER_ANNOTATED
    reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation
      is receptor kinase/co-receptor complex binding and signaling.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:32327536
  review:
    summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex
      context.
    action: MARK_AS_OVER_ANNOTATED
    reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation
      is receptor kinase/co-receptor complex binding and signaling.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:33514716
  review:
    summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex
      context.
    action: MARK_AS_OVER_ANNOTATED
    reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation
      is receptor kinase/co-receptor complex binding and signaling.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:35087541
  review:
    summary: The cited study reports a BAK1 interaction in brassinosteroid or immune receptor-complex
      context.
    action: MARK_AS_OVER_ANNOTATED
    reason: Generic protein binding is true but not informative for BAK1; the biologically useful curation
      is receptor kinase/co-receptor complex binding and signaling.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005524
    label: ATP binding
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  review:
    summary: ATP binding is expected for the BAK1 kinase domain.
    action: KEEP_AS_NON_CORE
    reason: This is compatible with kinase activity but less informative than receptor Ser/Thr kinase
      activity.
- term:
    id: GO:0033612
    label: receptor serine/threonine kinase binding
  evidence_type: IPI
  original_reference_id: PMID:19616764
  review:
    summary: BAK1 physically associates with receptor serine/threonine kinases in immune and growth signaling
      receptor complexes.
    action: ACCEPT
    reason: This specific binding term captures BAK1 co-receptor complex assembly better than generic
      protein binding.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
    - reference_id: PMID:19616764
      supporting_text: Upon recognition of bacterial flagellin, the plant receptor FLS2 heterodimerizes
        with brassinosteroid insensitive 1-associated receptor kinase 1 (BAK1).
      reference_section_type: ABSTRACT
- term:
    id: GO:0033612
    label: receptor serine/threonine kinase binding
  evidence_type: IPI
  original_reference_id: PMID:26320950
  review:
    summary: BAK1 physically associates with receptor serine/threonine kinases in immune and growth signaling
      receptor complexes.
    action: ACCEPT
    reason: This specific binding term captures BAK1 co-receptor complex assembly better than generic
      protein binding.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
    - reference_id: PMID:26320950
      supporting_text: BAK1 could co-immunoprecipitate both ER and ERL1 when expressed under the
        control of their native promoters in transgenic Arabidopsis plants, indicating that they
        associate in vivo.
      reference_section_type: RESULTS
- term:
    id: GO:0042802
    label: identical protein binding
  evidence_type: IPI
  original_reference_id: PMID:20018686
  review:
    summary: High-throughput or interaction evidence suggests BAK1 self-association or same-protein network
      context.
    action: MARK_AS_OVER_ANNOTATED
    reason: Identical protein binding is not the informative molecular function for BAK1 and should not
      be treated as a core annotation.
- term:
    id: GO:0042802
    label: identical protein binding
  evidence_type: IPI
  original_reference_id: PMID:29320478
  review:
    summary: High-throughput or interaction evidence suggests BAK1 self-association or same-protein network
      context.
    action: MARK_AS_OVER_ANNOTATED
    reason: Identical protein binding is not the informative molecular function for BAK1 and should not
      be treated as a core annotation.
- term:
    id: GO:0046982
    label: protein heterodimerization activity
  evidence_type: IPI
  original_reference_id: PMID:15548744
  review:
    summary: BAK1 forms heteromeric receptor complexes with BRI1/FLS2-family receptors after ligand perception.
    action: ACCEPT
    reason: Protein heterodimerization is a supported molecular feature of BAK1 receptor complex formation.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
    - reference_id: PMID:15548744
      supporting_text: BRI1 and AtSERK3 preferentially heterodimerize in the endosomes.
      reference_section_type: ABSTRACT
- term:
    id: GO:0106310
    label: protein serine kinase activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000116
  review:
    summary: BAK1 has catalytic activity as a membrane receptor-like Ser/Thr kinase, but protein serine
      kinase activity is less precise for this protein.
    action: MODIFY
    reason: The transmembrane receptor protein serine/threonine kinase activity term captures both the
      catalytic activity and receptor-like membrane context.
    proposed_replacement_terms:
    - id: GO:0004675
      label: transmembrane receptor protein serine/threonine kinase activity
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005768
    label: endosome
  evidence_type: IDA
  original_reference_id: PMID:15548744
  review:
    summary: BAK1 receptor complexes can undergo endocytic trafficking after signaling activation.
    action: KEEP_AS_NON_CORE
    reason: Endosome/endosome membrane localization is a supported trafficking state but secondary to
      the plasma membrane co-receptor role.
- term:
    id: GO:0005886
    label: plasma membrane
  evidence_type: IEA
  original_reference_id: GO_REF:0000044
  review:
    summary: BAK1 is a single-pass plasma-membrane receptor-like kinase/co-receptor.
    action: ACCEPT
    reason: Plasma membrane localization is central to BAK1 function in cell-surface receptor complexes.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005886
    label: plasma membrane
  evidence_type: ISM
  original_reference_id: GO_REF:0000122
  review:
    summary: BAK1 is a single-pass plasma-membrane receptor-like kinase/co-receptor.
    action: ACCEPT
    reason: Plasma membrane localization is central to BAK1 function in cell-surface receptor complexes.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005886
    label: plasma membrane
  evidence_type: IDA
  original_reference_id: PMID:12150928
  review:
    summary: BAK1 is a single-pass plasma-membrane receptor-like kinase/co-receptor.
    action: ACCEPT
    reason: Plasma membrane localization is central to BAK1 function in cell-surface receptor complexes.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005886
    label: plasma membrane
  evidence_type: EXP
  original_reference_id: PMID:12150929
  review:
    summary: BAK1 is a single-pass plasma-membrane receptor-like kinase/co-receptor.
    action: ACCEPT
    reason: Plasma membrane localization is central to BAK1 function in cell-surface receptor complexes.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005886
    label: plasma membrane
  evidence_type: HDA
  original_reference_id: PMID:14506206
  review:
    summary: BAK1 is a single-pass plasma-membrane receptor-like kinase/co-receptor.
    action: ACCEPT
    reason: Plasma membrane localization is central to BAK1 function in cell-surface receptor complexes.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005886
    label: plasma membrane
  evidence_type: EXP
  original_reference_id: PMID:15548744
  review:
    summary: BAK1 is a single-pass plasma-membrane receptor-like kinase/co-receptor.
    action: ACCEPT
    reason: Plasma membrane localization is central to BAK1 function in cell-surface receptor complexes.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005886
    label: plasma membrane
  evidence_type: HDA
  original_reference_id: PMID:17644812
  review:
    summary: BAK1 is a single-pass plasma-membrane receptor-like kinase/co-receptor.
    action: ACCEPT
    reason: Plasma membrane localization is central to BAK1 function in cell-surface receptor complexes.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005886
    label: plasma membrane
  evidence_type: IDA
  original_reference_id: PMID:18182375
  review:
    summary: BAK1 is a single-pass plasma-membrane receptor-like kinase/co-receptor.
    action: ACCEPT
    reason: Plasma membrane localization is central to BAK1 function in cell-surface receptor complexes.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005886
    label: plasma membrane
  evidence_type: IDA
  original_reference_id: PMID:19616764
  review:
    summary: BAK1 is a single-pass plasma-membrane receptor-like kinase/co-receptor.
    action: ACCEPT
    reason: Plasma membrane localization is central to BAK1 function in cell-surface receptor complexes.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005886
    label: plasma membrane
  evidence_type: EXP
  original_reference_id: PMID:26071421
  review:
    summary: BAK1 is a single-pass plasma-membrane receptor-like kinase/co-receptor.
    action: ACCEPT
    reason: Plasma membrane localization is central to BAK1 function in cell-surface receptor complexes.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0005886
    label: plasma membrane
  evidence_type: HDA
  original_reference_id: PMID:28887381
  review:
    summary: BAK1 is a single-pass plasma-membrane receptor-like kinase/co-receptor.
    action: ACCEPT
    reason: Plasma membrane localization is central to BAK1 function in cell-surface receptor complexes.
    supported_by:
    - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
      supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor
        for brassinosteroid and immune receptor complexes.
- term:
    id: GO:0010008
    label: endosome membrane
  evidence_type: IEA
  original_reference_id: GO_REF:0000044
  review:
    summary: BAK1 receptor complexes can undergo endocytic trafficking after signaling activation.
    action: KEEP_AS_NON_CORE
    reason: Endosome/endosome membrane localization is a supported trafficking state but secondary to
      the plasma membrane co-receptor role.
- term:
    id: GO:0010008
    label: endosome membrane
  evidence_type: EXP
  original_reference_id: PMID:15548744
  review:
    summary: BAK1 receptor complexes can undergo endocytic trafficking after signaling activation.
    action: KEEP_AS_NON_CORE
    reason: Endosome/endosome membrane localization is a supported trafficking state but secondary to
      the plasma membrane co-receptor role.
- term:
    id: GO:0032991
    label: protein-containing complex
  evidence_type: IPI
  original_reference_id: PMID:16473966
  review:
    summary: BAK1 participates in protein-containing receptor complexes with BRI1, FLS2/EFR/CERK-related
      receptors, and regulatory partners.
    action: KEEP_AS_NON_CORE
    reason: The generic complex term is directionally correct but less informative than specific receptor
      kinase/co-receptor complex annotations.
references:
- id: file:interpro/panther/PTHR47988/PTHR47988-entries.csv
  title: PANTHER PTHR47988 plant LRR receptor-like serine/threonine-protein kinases family context
  findings: []
- id: file:interpro/panther/PTHR47988/PTHR47988-metadata.yaml
  title: PANTHER PTHR47988 plant LRR receptor-like serine/threonine-protein kinases family context
  findings: []
- id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
  title: Falcon deep research report for Arabidopsis BAK1
  findings:
  - statement: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for brassinosteroid
      and immune receptor complexes.
- id: file:ARATH/BAK1/BAK1-uniprot.txt
  title: UniProtKB record for Arabidopsis BAK1
  findings: []
- id: GO_REF:0000002
  title: Gene Ontology annotation through association of InterPro records with GO terms
  findings: []
- id: GO_REF:0000003
  title: Gene Ontology annotation based on Enzyme Commission mapping
  findings: []
- id: GO_REF:0000044
  title: Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping,
    accompanied by conservative changes to GO terms applied by UniProt
  findings: []
- id: GO_REF:0000116
  title: Automatic Gene Ontology annotation based on Rhea mapping
  findings: []
- id: GO_REF:0000122
  title: AtSubP analysis
  findings: []
- id: PMID:12150928
  title: BRI1/BAK1, a receptor kinase pair mediating brassinosteroid signaling.
  findings: []
- id: PMID:12150929
  title: BAK1, an Arabidopsis LRR receptor-like protein kinase, interacts with BRI1 and modulates brassinosteroid
    signaling.
  findings: []
- id: PMID:14506206
  title: Large-scale analysis of in vivo phosphorylated membrane proteins by immobilized metal ion affinity
    chromatography and mass spectrometry.
  findings: []
- id: PMID:15548744
  title: Heterodimerization and endocytosis of Arabidopsis brassinosteroid receptors BRI1 and AtSERK3
    (BAK1).
  findings: []
- id: PMID:16473966
  title: The Arabidopsis SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE1 protein complex includes BRASSINOSTEROID-INSENSITIVE1.
  findings: []
- id: PMID:16857903
  title: Brassinosteroids regulate dissociation of BKI1, a negative regulator of BRI1 signaling, from
    the plasma membrane.
  findings: []
- id: PMID:17583510
  title: The BRI1-associated kinase 1, BAK1, has a brassinolide-independent role in plant cell-death control.
  findings: []
- id: PMID:17625569
  title: A flagellin-induced complex of the receptor FLS2 and BAK1 initiates plant defence.
  findings: []
- id: PMID:17626179
  title: The receptor-like kinase SERK3/BAK1 is a central regulator of innate immunity in plants.
  findings:
  - statement: BAK1/SERK3 is required for early PAMP-triggered immune responses and enters a flg22-dependent
      FLS2 receptor complex.
    supporting_text: >-
      In Arabidopsis thaliana, AtSERK3/BAK1 rapidly enters an elicitor-dependent
      complex with FLAGELLIN SENSING 2 (FLS2), the receptor for the bacterial
      PAMP flagellin and its peptide derivative flg22. In the absence of
      AtSERK3/BAK1, early flg22-dependent responses are greatly reduced.
    reference_section_type: ABSTRACT
- id: PMID:17644812
  title: A high content in lipid-modified peripheral proteins and integral receptor kinases features in
    the arabidopsis plasma membrane proteome.
  findings: []
- id: PMID:18182375
  title: Proteomics studies of brassinosteroid signal transduction using prefractionation and two-dimensional
    DIGE.
  findings: []
- id: PMID:18667726
  title: Arabidopsis SOMATIC EMBRYOGENESIS RECEPTOR KINASE proteins serve brassinosteroid-dependent and
    -independent signaling pathways.
  findings: []
- id: PMID:19452453
  title: Proteomic profiling of tandem affinity purified 14-3-3 protein complexes in Arabidopsis thaliana.
  findings: []
- id: PMID:19532123
  title: Membrane steroid-binding protein 1 (MSBP1) negatively regulates brassinosteroid signaling by
    enhancing the endocytosis of BAK1.
  findings: []
- id: PMID:19616764
  title: Regulation of cell death and innate immunity by two receptor-like kinases in Arabidopsis.
  findings: []
- id: PMID:20018686
  title: A receptor-like cytoplasmic kinase, BIK1, associates with a flagellin receptor complex to initiate
    plant innate immunity.
  findings: []
- id: PMID:21499263
  title: Stem-cell-triggered immunity through CLV3p-FLS2 signalling.
  findings: []
- id: PMID:21680842
  title: Direct ubiquitination of pattern recognition receptor FLS2 attenuates plant innate immunity.
  findings: []
- id: PMID:22087006
  title: Brassinosteroids inhibit pathogen-associated molecular pattern-triggered immune signaling independent
    of the receptor kinase BAK1.
  findings: []
- id: PMID:22184234
  title: Deactivation of the Arabidopsis BRASSINOSTEROID INSENSITIVE 1 (BRI1) receptor kinase by autophosphorylation
    within the glycine-rich loop.
  findings: []
- id: PMID:22253607
  title: Genetic evidence for an indispensable role of somatic embryogenesis receptor kinases in brassinosteroid
    signaling.
  findings: []
- id: PMID:24114786
  title: Structural basis for flg22-induced activation of the Arabidopsis FLS2-BAK1 immune complex.
  findings: []
- id: PMID:24388849
  title: The leucine-rich repeat receptor kinase BIR2 is a negative regulator of BAK1 in plant immunity.
  findings: []
- id: PMID:24556575
  title: Structure of the pseudokinase domain of BIR2, a regulator of BAK1-mediated immune signaling in
    Arabidopsis.
  findings: []
- id: PMID:24625928
  title: A bacterial tyrosine phosphatase inhibits plant pattern recognition receptor activation.
  findings: []
- id: PMID:26071421
  title: Phytosulfokine Regulates Growth in Arabidopsis through a Response Module at the Plasma Membrane
    That Includes CYCLIC NUCLEOTIDE-GATED CHANNEL17, H+-ATPase, and BAK1.
  findings: []
- id: PMID:26308901
  title: Allosteric receptor activation by the plant peptide hormone phytosulfokine.
  findings: []
- id: PMID:26320950
  title: Differential Function of Arabidopsis SERK Family Receptor-like Kinases in Stomatal Patterning.
  findings: []
- id: PMID:27229311
  title: Signature motif-guided identification of receptors for peptide hormones essential for root meristem
    growth.
  findings: []
- id: PMID:27317676
  title: The Arabidopsis Malectin-Like/LRR-RLK IOS1 Is Critical for BAK1-Dependent and BAK1-Independent
    Pattern-Triggered Immunity.
  findings: []
- id: PMID:28887381
  title: Global Analysis of Membrane-associated Protein Oligomerization Using Protein Correlation Profiling.
  findings: []
- id: PMID:29320478
  title: An extracellular network of Arabidopsis leucine-rich repeat receptor kinases.
  findings: []
- id: PMID:30806640
  title: Map of physical interactions between extracellular domains of Arabidopsis leucine-rich repeat
    receptor kinases.
  findings: []
- id: PMID:32327536
  title: STRESS INDUCED FACTOR 2 Regulates Arabidopsis Stomatal Immunity through Phosphorylation of the
    Anion Channel SLAC1.
  findings: []
- id: PMID:33514716
  title: Perception of a divergent family of phytocytokines by the Arabidopsis receptor kinase MIK2.
  findings: []
- id: PMID:35087541
  title: The Phloem Intercalated With Xylem-Correlated 3 Receptor-Like Kinase Constitutively Interacts
    With Brassinosteroid Insensitive 1-Associated Receptor Kinase 1 and Is Involved in Vascular Development
    in Arabidopsis.
  findings: []
core_functions:
- description: Plasma-membrane LRR receptor-like Ser/Thr co-receptor kinase activity in brassinosteroid
    and pattern-recognition receptor complexes. BAK1/SERK3 binds ligand-activated receptors, contributes
    receptor-complex phosphorylation, and enables downstream growth and immune signaling.
  molecular_function:
    id: GO:0004675
    label: transmembrane receptor protein serine/threonine kinase activity
  directly_involved_in:
  - id: GO:0009742
    label: brassinosteroid mediated signaling pathway
  - id: GO:0140426
    label: pathogen-associated molecular pattern receptor signaling pathway
  locations:
  - id: GO:0005886
    label: plasma membrane
  supported_by:
  - reference_id: file:ARATH/BAK1/BAK1-deep-research-falcon.md
    supporting_text: Falcon report summarizes BAK1/SERK3 as an LRR receptor-like kinase co-receptor for
      brassinosteroid and immune receptor complexes.
  - reference_id: file:interpro/panther/PTHR47988/PTHR47988-metadata.yaml
    supporting_text: PTHR47988 is a plant LRR receptor-like serine/threonine-protein kinase family.
suggested_questions:
- question: Which BAK1 protein-binding annotations should be replaced by more specific GO terms for receptor
    kinase/co-receptor complex assembly?
- question: Which immune and brassinosteroid receptor complexes require BAK1 catalytic activity versus
    scaffold/co-receptor binding only?
suggested_experiments:
- experiment_type: phosphoproteomics
  hypothesis: BAK1 catalytic activity produces receptor-complex-specific phosphorylation signatures in
    brassinosteroid and PAMP signaling.
  description: Compare ligand-induced phosphoproteomes in native BAK1, kinase-dead BAK1, and receptor-specific
    mutant backgrounds after brassinolide and flg22 treatments.
- experiment_type: interaction specificity
  hypothesis: Different BAK1 receptor-complex partners explain the diverse generic protein-binding annotations.
  description: Use endogenous tagged BAK1 affinity purification under ligand-specific treatments followed
    by quantitative MS and targeted validation of receptor/RLCK partners.
proposed_new_terms: []

Gene Description

Existing Annotations Review

Core Functions

Plasma-membrane LRR receptor-like Ser/Thr co-receptor kinase activity in brassinosteroid and pattern-recognition receptor complexes. BAK1/SERK3 binds ligand-activated receptors, contributes receptor-complex phosphorylation, and enables downstream growth and immune signaling.

References

Suggested Questions for Experts

Suggested Experiments

Deep Research

Falcon

Comprehensive Research Report: BAK1 / SERK3 (Arabidopsis thaliana; UniProt Q94F62; locus At4g33430)

Executive summary

1) Key concepts, definitions, and current understanding

1.1. What BAK1 is (verified identity)

1.2. RLK and co-receptor definitions

1.3. Domain architecture of BAK1 (functional inference + experimental support)

1.4. RD vs non-RD kinases (relevance to BAK1 signaling logic)

2) Functional annotation of BAK1/SERK3

2.1. Primary molecular function

2.2. Cellular location and trafficking

2.3. Pathways and biological processes

(A) Brassinosteroid growth signaling (BRI1–BAK1 module)

(B) Pattern-triggered immunity (PRR–BAK1 module)

3) Recent developments and latest research (prioritizing 2023–2024)

3.1. 2024 eLife: Allosteric activation model in EFR–BAK1 immune signaling

3.2. 2024 Nature Plants: Structure/function of MIK2–SCOOP–BAK1 complexes and N-glycan dependence

3.3. 2024 Nature Plants review: cell-surface organization and trafficking in BR signaling

3.4. 2023–2024 reviews: RLK architecture and growth–stress balancing

4) Current applications and real-world implementations

4.1. Engineering crop immunity via PRR/co-receptor modules

4.2. BR pathway manipulation for agronomic traits (yield vs defense tradeoff)

4.3. Mechanism-informed engineering opportunities from 2024 structural work

5) Expert opinions and analysis (authoritative sources)

5.1. BAK1 as a central hub at the cell surface

5.2. Signal specificity and pathway separation

5.3. Updated mechanistic perspective (2024)

Evidence summary table

Image-based evidence (quantitative structural data)

Limitations of this report (scope and evidence availability)

Citations

📄 View Raw YAML