Q94F62 · BAK1_ARATH

Function

function

Dual specificity kinase acting on both serine/threonine- and tyrosine-containing substrates. Controls the expression of genes associated with innate immunity in the absence of pathogens or elicitors. Involved in brassinosteroid (BR) signal transduction. Phosphorylates BRI1. May be involved in changing the equilibrium between plasma membrane-located BRI1 homodimers and endocytosed BRI1-BAK1 heterodimers. Interaction with MSBP1 stimulates the endocytosis of BAK1 and suppresses brassinosteroid signaling. Acts in pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) via its interactions with FLS2 and EFR, and the phosphorylation of BIK1. Involved in programmed cell death (PCD) control. Positively regulates the BR-dependent plant growth pathway and negatively regulates the BR-independent cell-death pathway (PubMed:17583510, PubMed:17600708, PubMed:18667726, PubMed:18694562, PubMed:19124768, PubMed:20018402, PubMed:20404519, PubMed:21693696).
Phosphorylates BIR2 and thus promotes interaction with BIR2 (PubMed:24388849, PubMed:24556575).
This interaction prevents interaction with FLS2 in the absence of pathogen-associated molecular patterns (PAMP) (PubMed:24388849, PubMed:24556575).
Component of the RLP23-SOBIR1-BAK1 complex that mediates NLP-triggered immunity (PubMed:27251392).
Required for PSK promotion of seedling growth and protoplast expansion (PubMed:26071421).
CNGC17 and AHAs form a functional cation-translocating unit that is activated by PSKR1/BAK1 and possibly other BAK1/RLK complexes (PubMed:26071421).
Required during SCOOP small peptides (e.g. RGF1, SCOOP10 and SCOOP12) perception and signaling; associates with MIK2 as a coreceptor upon MIK2 perception of SCOOP peptides, and relays the signaling through the activation of receptor-like cytosolic kinases (RLCKs) BIK1 and PBL1 (Probable) (PubMed:30715439, PubMed:34535661).

Miscellaneous

Interaction with BRI1 activates both receptor kinases and the full activation of either receptor kinase requires transphosphorylation by their partners. This interaction in vitro is magnesium dependent. Instantaneous heteromeric complex formation between FLS2 and BAK1 and reciprocal transphosphorylation after binding of the flagellin flg22 ligand to FLS2. The kinase activity is not required for the complex formation.
The interaction with the bacterial effectors AvrPto and AvrPtoB/hopAB2 interferes with FLS2 binding and plant immunity.
Phosphorylated residues T-450 and T-455 have stronger functional effects than other phosphorylated residues by interacting with both the catalytic and activation loops to achieve a conformational stability, locking BAK1 kinase in the active conformation.

Caution

An article reported the role of autophosphorylation of Tyr-610 in brassinosteroid signaling; however, this paper was later retracted. A second article from the same group reported the role of phosphorylation; however, this paper was also retracted.

Catalytic activity

Features

Showing features for site, binding site, active site.

TypeIDPosition(s)Description
Site52Interacts with flagellin flg22
Site54Interacts with flagellin flg22; via amide nitrogen
Binding site59brassinolide (UniProtKB | ChEBI)
Binding site60brassinolide (UniProtKB | ChEBI)
Binding site61brassinolide (UniProtKB | ChEBI)
Binding site62brassinolide (UniProtKB | ChEBI)
Binding site295-303ATP (UniProtKB | ChEBI)
Binding site317ATP (UniProtKB | ChEBI)
Binding site364ATP (UniProtKB | ChEBI)
Binding site365ATP (UniProtKB | ChEBI)
Binding site366ATP (UniProtKB | ChEBI)
Active site416Proton acceptor
Binding site418ATP (UniProtKB | ChEBI)

GO annotations

AspectTerm
Cellular Componentendosome membrane
Cellular Componentplasma membrane
Molecular FunctionATP binding
Molecular Functionidentical protein binding
Molecular Functionprotein serine kinase activity
Molecular Functionprotein serine/threonine kinase activity
Molecular Functionreceptor serine/threonine kinase binding
Molecular Functionsignaling receptor binding
Molecular Functiontransmembrane receptor protein tyrosine kinase activity
Biological Processdefense response

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    BRASSINOSTEROID INSENSITIVE 1-associated receptor kinase 1
  • EC number
  • Short names
    AtBAK1
    ; BRI1-associated receptor kinase 1
  • Alternative names
    • Protein ELONGATED
    • Somatic embryogenesis receptor kinase 3
      (AtSERK3
      )
    • Somatic embryogenesis receptor-like kinase 3

Gene names

    • Name
      BAK1
    • Synonyms
      ELG, SERK3
    • ORF names
      F17M5.190
    • Ordered locus names
      At4g33430

Organism names

  • Taxonomic identifier
  • Strains
    • cv. Landsberg erecta
    • cv. Columbia
  • Taxonomic lineage
    Eukaryota > Viridiplantae > Streptophyta > Embryophyta > Tracheophyta > Spermatophyta > Magnoliopsida > eudicotyledons > Gunneridae > Pentapetalae > rosids > malvids > Brassicales > Brassicaceae > Camelineae > Arabidopsis

Accessions

  • Primary accession
    Q94F62
  • Secondary accessions
    • C0LGS0
    • Q9SZC0

Proteomes

Organism-specific databases

Genome annotation databases

Subcellular Location

Cell membrane
; Single-pass type I membrane protein
Endosome membrane
; Single-pass type I membrane protein
Note: Endocytosis enhanced upon interaction with MSBP1.

Features

Showing features for topological domain, transmembrane.

TypeIDPosition(s)Description
Topological domain26-225Extracellular
Transmembrane226-246Helical
Topological domain247-615Cytoplasmic

Keywords

Phenotypes & Variants

Disruption phenotype

Semi-dwarfed phenotype, altered leaf morphology and reduced sensitivity to brassinolide and flagellin. Enhanced chlorosis and lesion formation upon pathogen infection. Bak1 and bkk1 double mutants are seedling lethal. Impaired SCOOP12-mediated growth inhibition (PubMed:30715439).
Partially compromised SCOOP10- and SCOOP12-induced root growth inhibition and reactive oxygen species (ROS) production; fully compromised in the double mutant bak1-5 serk4 (PubMed:34535661).

Features

Showing features for mutagenesis.

TypeIDPosition(s)Description
Mutagenesis30No effect on flg22 induced FLS2-BAK1 heterodimerization.
Mutagenesis32Loss of binding to BRI1, but no effect on kinase activity.
Mutagenesis46Loss of binding to BRI1 and loss of kinase activity.
Mutagenesis60Loss of flg22 induced FLS2-BAK1 heterodimerization.
Mutagenesis64No effect.
Mutagenesis94No effect.
Mutagenesis96Loss of flg22 induced FLS2-BAK1 heterodimerization.
Mutagenesis121No effect.
Mutagenesis122Hypersensitivity to brassinosteroids and enhanced high-light phototropism.
Mutagenesis144Loss of flg22 induced FLS2-BAK1 heterodimerization.
Mutagenesis172No effect.
Mutagenesis286No effect.
Mutagenesis286Loss of kinase activity.
Mutagenesis290Reduced kinase activity. Reduced interaction with BIR2.
Mutagenesis290Normal interaction with BIR2.
Mutagenesis312No effect on the kinase activity or on the binding to the FHA domain of KAPP. Reduced interaction with BIR2.
Mutagenesis312Reduced interaction with BIR2.
Mutagenesis317Loss of kinase activity and loss of interaction with hopAB2/AvrPtoB, but no effect on the binding to the FHA domain of KAPP. Reduced interaction with BIR2.
Mutagenesis363Loss of autophosphorylation.
Mutagenesis416Loss of phosphorylation.
Mutagenesis421Loss of phosphorylation.
Mutagenesis439No effect on some phosphorylation sites.
Mutagenesis446No effect. Reduced interaction with BIR2. Loss of kinase activity; when associated with D-449 and D-450.
Mutagenesis449Slight decrease of kinase activity but loss of interaction with hopAB2/AvrPtoB. Reduced interaction with BIR2. Loss of kinase activity; when associated with A-446 and D-450.
Mutagenesis450Loss of interaction with hopAB2/AvrPtoB and loss of phosphorylation. Reduced interaction with BIR2. Loss of kinase activity; when associated with A-446 and D-449.
Mutagenesis451Loss of kinase activity and loss of interaction with hopAB2/AvrPtoB. Reduced interaction with BIR2.
Mutagenesis452Strongly decreased kinase activity and loss of interaction with hopAB2/AvrPtoB.
Mutagenesis453No effect on some phosphorylation sites.
Mutagenesis455Loss of kinase activity.
Mutagenesis455Loss of kinase activity and loss of interaction with hopAB2/AvrPtoB.
Mutagenesis456Loss of kinase activity and loss of interaction with hopAB2/AvrPtoB.
Mutagenesis458Loss of kinase activity, loss of phosphorylation and loss of interaction with hopAB2/AvrPtoB.
Mutagenesis464Loss of kinase activity and loss of interaction with hopAB2/AvrPtoB.
Mutagenesis495Loss of kinase activity and loss of interaction with hopAB2/AvrPtoB.
Mutagenesis54660% decrease of binding to the FHA domain of KAPP.

Variants

We now provide the "Disease & Variants" viewer in its own tab.

The viewer provides 3 variants from UniProt as well as other sources including ClinVar and dbSNP.

Go to variant viewer

PTM/Processing

Features

Showing features for signal, chain, disulfide bond, glycosylation, modified residue.

TypeIDPosition(s)Description
Signal1-25
ChainPRO_000002430426-615BRASSINOSTEROID INSENSITIVE 1-associated receptor kinase 1
Disulfide bond57↔64
Glycosylation79N-linked (GlcNAc...) asparagine
Glycosylation103N-linked (GlcNAc...) asparagine
Glycosylation114N-linked (GlcNAc...) asparagine
Glycosylation127N-linked (GlcNAc...) asparagine
Glycosylation149N-linked (GlcNAc...) asparagine
Glycosylation183N-linked (GlcNAc...) asparagine
Modified residue286Phosphoserine
Modified residue290Phosphoserine
Modified residue312Phosphothreonine
Modified residue370Phosphoserine
Modified residue373Phosphoserine
Modified residue446Phosphothreonine
Modified residue449Phosphothreonine
Modified residue450Phosphothreonine
Modified residue455Phosphothreonine
Modified residue463Phosphotyrosine
Modified residue465Phosphoserine
Modified residue466Phosphothreonine
Modified residue470Phosphoserine
Modified residue546Phosphothreonine
Modified residue589Phosphothreonine
Modified residue595Phosphoserine
Modified residue604Phosphoserine
Modified residue612Phosphoserine

Post-translational modification

Autophosphorylated on Ser-290, Thr-312, Thr-446, Thr-449, Thr-455 and Tyr-610. Probable autophosphorylation on additional Tyr residues. Transphosphorylated by BRI1. It is not sure whether Thr-589 or Ser-595 is the target of the phosphorylation. The phosphorylations on Thr and Tyr are induced by brassinolide. Phosphorylation at Ser-286, Ser-290 Thr-446 or Thr-449 is not critical for flagellin signaling. Phosphorylated on Ser-612 upon SCOOP12 detection; a post-translational modification required for immune signaling (PubMed:33514716).

Keywords

Proteomic databases

PTM databases

Expression

Tissue specificity

Expressed ubiquitously.

Induction

Up-regulated by flagellin and harpin.

Gene expression databases

Interaction

Subunit

Interacts constitutively with BIR2, thereby preventing interaction with the ligand-binding LRR-RLK FLS2. Upon infection, pathogen-associated molecular patterns (PAMP) perception leads to BIR2 release from the BAK1 complex and enables the recruitment of BAK1 into the FLS2 complex (PubMed:24388849, PubMed:24556575).
Heterodimer with FLS2 (PubMed:24114786).
Monomer. Heterodimer with BRI1 in the endosomes. Component of the SERK1 signaling complex, composed of KAPP, CDC48A, GRF6 or GRF7, SERK1, SERK2, SERK3/BAK1 and BRI1. Interacts with the P.syringae AvrPto and hopAB2/AvrPtoB, ERD13, PEPR1 and PEPR2. Interacts (via extracellular region) with MSBP1. Interacts with the EF-Tu receptor EFR and FLS2 in a specific ligand-induced manner. Interacts with TMK4/BARK1. Part of a functional complex containing PSKR1, BAK1, CNGC17, and AHA (PubMed:26071421).
Interacts with CNGC17 and PSKR1 (PubMed:26071421).
Binds to IOS1 which triggers FLS2-BAK1 complex formation upon microbe-associated molecular patterns (MAMPs) treatment (PubMed:27317676).
Interacts with ERECTA in a EPF2-induced manner. Interacts with ERL1 in a EPF1-induced manner. Interacts with TMM (PubMed:26320950).
Component of a trimeric complex composed of RLP23, SOBIR1 and BAK1. BAK1 is recruited into a pre-formed RLP23-SOBIR1 complex in a ligand-dependent manner (PubMed:27251392).
In the presence of the signal peptide RGF1, interacts with RGI3/RGFR1 and RGI4/RGFR2/SKM2 (PubMed:27229311).
Forms a complex with MIK2 in response to SCOOP12 perception (PubMed:33514716, PubMed:34535661).

Binary interactions

TypeEntry 1Entry 2Number of experimentsIntact
BINARY Q94F62At1g27190 O045672EBI-617138, EBI-1238687
BINARY Q94F62At1g69990 C0LGI54EBI-617138, EBI-20651225
BINARY Q94F62At2g14510 Q9ZQR32EBI-617138, EBI-20651957
BINARY Q94F62At4g30520 Q8VYT32EBI-617138, EBI-16902452
BINARY Q94F62At5g48380 Q9ASS46EBI-617138, EBI-6298290
BINARY Q94F62BAK1 Q94F624EBI-617138, EBI-617138
BINARY Q94F62BIK1 O488145EBI-617138, EBI-1238176
BINARY Q94F62BRI1 O224769EBI-617138, EBI-1797828
BINARY Q94F62BRL1 Q9ZWC87EBI-617138, EBI-590903
BINARY Q94F62BRL3 Q9LJF32EBI-617138, EBI-20651413
BINARY Q94F62EFR C0LGT63EBI-617138, EBI-8801168
BINARY Q94F62ERECTA Q423714EBI-617138, EBI-16940407
BINARY Q94F62ERL1 C0LGW64EBI-617138, EBI-16914248
BINARY Q94F62ERL2 Q6XAT24EBI-617138, EBI-16895926
XENO Q94F62fliC P211845EBI-617138, EBI-16077660
BINARY Q94F62FLS2 Q9FL2819EBI-617138, EBI-1799448
BINARY Q94F62HSL2 C0LGX32EBI-617138, EBI-16904927
BINARY Q94F62IOS1 Q9C8I62EBI-617138, EBI-16924837
BINARY Q94F62LRR-RLK Q9ZVD42EBI-617138, EBI-20651739
BINARY Q94F62NIK1 Q9LFS44EBI-617138, EBI-16146189
BINARY Q94F62NIK2 Q8RY652EBI-617138, EBI-20664696
BINARY Q94F62PSKR1 Q9ZVR75EBI-617138, EBI-16172949
BINARY Q94F62PSY1R Q9C7S52EBI-617138, EBI-16904988
BINARY Q94F62RPK1 Q9ZRF94EBI-617138, EBI-1238953
BINARY Q94F62SERK1 Q94AG26EBI-617138, EBI-1555537
BINARY Q94F62SERK4 Q9SKG54EBI-617138, EBI-6290483
BINARY Q94F62SERK5 Q8LPS54EBI-617138, EBI-16887868
BINARY Q94F62SRF1 Q06BH32EBI-617138, EBI-16955764
BINARY Q94F62SRF3 Q6R2K32EBI-617138, EBI-20651925
BINARY Q94F62SRF5 Q6R2K14EBI-617138, EBI-20651875
BINARY Q94F62SRF6 Q9C8M94EBI-617138, EBI-16954301
BINARY Q94F62SRF7 Q9LUL42EBI-617138, EBI-16964596
BINARY Q94F62SUB Q8RWZ14EBI-617138, EBI-17072125

Protein-protein interaction databases

Family & Domains

Features

Showing features for motif, repeat, domain.

TypeIDPosition(s)Description
Motif57-64Cys pair
Repeat67-90LRR 1
Repeat91-115LRR 2
Repeat117-139LRR 3
Repeat140-163LRR 4
Repeat165-188LRR 5
Repeat190-209LRR 6
Domain289-576Protein kinase

Domain

Contains one leucine-zipper motif and one pair of conservatively spaced Cys (Cys pair) involved in forming heterodimers.

Sequence similarities

Belongs to the protein kinase superfamily. Ser/Thr protein kinase family.

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Sequence processing
    The displayed sequence is further processed into a mature form.

This entry describes 1 isoforms produced by Alternative splicing. A number of isoforms are produced. According to EST sequences.

Q94F62-1

This isoform has been chosen as the canonical sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.

  • Length
    615
  • Mass (Da)
    68,161
  • Last updated
    2003-03-28 v2
  • Checksum
    547B3F38FB46E1DD
MERRLMIPCFFWLILVLDLVLRVSGNAEGDALSALKNSLADPNKVLQSWDATLVTPCTWFHVTCNSDNSVTRVDLGNANLSGQLVMQLGQLPNLQYLELYSNNITGTIPEQLGNLTELVSLDLYLNNLSGPIPSTLGRLKKLRFLRLNNNSLSGEIPRSLTAVLTLQVLDLSNNPLTGDIPVNGSFSLFTPISFANTKLTPLPASPPPPISPTPPSPAGSNRITGAIAGGVAAGAALLFAVPAIALAWWRRKKPQDHFFDVPAEEDPEVHLGQLKRFSLRELQVASDNFSNKNILGRGGFGKVYKGRLADGTLVAVKRLKEERTQGGELQFQTEVEMISMAVHRNLLRLRGFCMTPTERLLVYPYMANGSVASCLRERPESQPPLDWPKRQRIALGSARGLAYLHDHCDPKIIHRDVKAANILLDEEFEAVVGDFGLAKLMDYKDTHVTTAVRGTIGHIAPEYLSTGKSSEKTDVFGYGVMLLELITGQRAFDLARLANDDDVMLLDWVKGLLKEKKLEALVDVDLQGNYKDEEVEQLIQVALLCTQSSPMERPKMSEVVRMLEGDGLAERWEEWQKEEMFRQDFNYPTHHPAVSGWIIGDSTSQIENEYPSGPR

Computationally mapped potential isoform sequences

There is 1 potential isoform mapped to this entry

View all
EntryEntry nameGene nameLength
F4JIX9F4JIX9_ARATHBAK1662

Sequence caution

The sequence CAB38801.1 differs from that shown. Reason: Erroneous gene model prediction
The sequence CAB80060.1 differs from that shown. Reason: Erroneous gene model prediction

Features

Showing features for sequence conflict.

TypeIDPosition(s)Description
Sequence conflict12in Ref. 1; AAK68074

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
AF384970
EMBL· GenBank· DDBJ
AAK68074.1
EMBL· GenBank· DDBJ
mRNA
FJ708762
EMBL· GenBank· DDBJ
ACN59355.1
EMBL· GenBank· DDBJ
mRNA
AL035678
EMBL· GenBank· DDBJ
CAB38801.1
EMBL· GenBank· DDBJ
Genomic DNA Sequence problems.
AL161583
EMBL· GenBank· DDBJ
CAB80060.1
EMBL· GenBank· DDBJ
Genomic DNA Sequence problems.
CP002687
EMBL· GenBank· DDBJ
AEE86223.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

Disclaimer

Any medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care. Our staff consists of biologists and biochemists that are not trained to give medical advice.
We'd like to inform you that we have updated our Privacy Notice to comply with Europe’s new General Data Protection Regulation (GDPR) that applies since 25 May 2018.
FeedbackHelp