Seroatlas · Human Serome Atlas

IBTK

Inhibitor of Bruton tyrosine kinase

Also known as: BTBD26, BTKI, DKFZP564B116, IBTK_HUMAN

Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene

Protein identityUniProt · HPA

UniProt accession
Q9P2D0
Gene
IBTK
Ensembl
ENSG00000005700
Chromosome
6
Canonical length
1353 aa
Protein class
Predicted intracellular proteins
Subcellular location
Nucleoplasm

OverviewNCBI Gene

Bruton tyrosine kinase (BTK) is a protein tyrosine kinase that is expressed in B cells, macrophages, and neutrophils. The protein encoded by this gene binds to BTK and downregulates BTK's kinase activity. In addition, the encoded protein disrupts BTK-mediated calcium mobilization and negatively regulates the activation of nuclear factor-kappa-B-driven transcription. This gene has a pseudogene on chromosome 18. Alternative splicing results in multiple transcript variants encoding distinct isoforms. [provided by RefSeq, Jul 2014]

Canonical amino-acid sequenceUniProt

1353 residues, UniProt reviewed canonical sequence.

>Q9P2D0|IBTK
     1  MSSPMPDCTS KCRSLKHALD VLSVVTKGSE NQIKAFLSSH CYNAATIKDV FGRNALHLVS
    61  SCGKKGVLDW LIQKGVDLLV KDKESGWTAL HRSIFYGHID CVWSLLKHGV SLYIQDKEGL
   121  SALDLVMKDR PTHVVFKNTD PTDVYTWGDN TNFTLGHGSQ NSKHHPELVD LFSRSGIYIK
   181  QVVLCKFHSV FLSQKGQVYT CGHGPGGRLG HGDEQTCLVP RLVEGLNGHN CSQVAAAKDH
   241  TVVLTEDGCV YTFGLNIFHQ LGIIPPPSSC NVPRQIQAKY LKGRTIIGVA AGRFHTVLWT
   301  REAVYTMGLN GGQLGCLLDP NGEKCVTAPR QVSALHHKDI ALSLVAASDG ATVCVTTRGD
   361  IYLLADYQCK KMASKQLNLK KVLVSGGHME YKVDPEHLKE NGGQKICILA MDGAGRVFCW
   421  RSVNSSLKQC RWAYPRQVFI SDIALNRNEI LFVTQDGEGF RGRWFEEKRK SSEKKEILSN
   481  LHNSSSDVSY VSDINSVYER IRLEKLTFAH RAVSVSTDPS GCNFAILQSD PKTSLYEIPA
   541  VSSSSFFEEF GKLLREADEM DSIHDVTFQV GNRLFPAHKY ILAVHSDFFQ KLFLSDGNTS
   601  EFTDIYQKDE DSAGCHLFVV EKVHPDMFEY LLQFIYTDTC DFLTHGFKPR IHLNKNPEEY
   661  QGTLNSHLNK VNFHEDDNQK SAFEVYKSNQ AQTVSERQKS KPKSCKKGKN IREDDPVRML
   721  QTVAKKFDFS NLSSRLDGVR FENEKINVIA KNTGNKLKLS QKKCSFLCDV TMKSVDGKEF
   781  PCHKCVLCAR LEYFHSMLSS SWIEASSCAA LEMPIHSDIL KVILDYLYTD EAVVIKESQN
   841  VDFICSVLVV ADQLLITRLK EICEVALTEK LTLKNAAMLL EFAAMYSAKQ LKLSCLQFIG
   901  LNMAALLEAR SLDVLSDGVL KDLSEFYRKM IPAMDRRVIT PYQDGPDISY LEVEDGDIFL
   961  KEEINMEQNH SETMFKKAKT KAKKKPRKRS DSSGGYNLSD IIQSPSSTGL LKSGKTNSVE
  1021  SLPELLTSDS EGSYAGVGSP RDLQSPDFTT GFHSDKIEAK VKPYVNGTSP VYSREDLKPW
  1081  EKSPILKISA PQPIPSNRID TTSSASWVAG SFSPVSPPVV DLRTIMEIEE SRQKCGATPK
  1141  SHLGKTVSHG VKLSQKQRKM IALTTKENNS GMNSMETVLF TPSKAPKPVN AWASSLHSVS
  1201  SKSFRDFLLE EKKSVTSHSS GDHVKKVSFK GIENSQAPKI VRCSTHGTPG PEGNHISDLP
  1261  LLDSPNPWLS SSVTAPSMVA PVTFASIVEE ELQQEAALIR SREKPLALIQ IEEHAIQDLL
  1321  VFYEAFGNPE EFVIVERTPQ GPLAVPMWNK HGC

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against IBTK can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability
Intracellular
Secreted
No
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.39
Highest tissue expression
21 nTPM

Expression across tissuesHPA

Tissue

  • liver: 21 nTPM
  • skeletal muscle: 20 nTPM
  • tongue: 20 nTPM
  • adrenal gland: 13 nTPM
  • parathyroid gland: 12 nTPM
  • stomach: 11 nTPM

Single-cell type

  • oligodendrocytes: 185 nCPM
  • microglia: 144 nCPM
  • choroid plexus epithelial cells: 142 nCPM
  • brain inhibitory neurons: 126 nCPM
  • brain excitatory neurons: 119 nCPM
  • distal convoluted tubule cells: 117 nCPM

Immune cell

  • T-reg: 2.7 nTPM
  • MAIT T-cell: 2.4 nTPM
  • non-classical monocyte: 2.3 nTPM
  • myeloid DC: 1.9 nTPM
  • gdT-cell: 1.8 nTPM
  • memory CD4 T-cell: 1.8 nTPM

Brain region

  • spinal cord: 8.9 nTPM
  • white matter: 8.6 nTPM
  • midbrain: 8.5 nTPM
  • thalamus: 8.2 nTPM
  • basal ganglia: 8.1 nTPM
  • cerebellum: 8 nTPM

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance)
0.41
gnomAD pLI
0
gnomAD missense Z
2.28
DepMap mean gene effect
0.02
DepMap dependency class
none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 4% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of IBTK in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads IBTK as an antibody target. Whether an autoantibody or antibody against IBTK could matter depends on whether native IBTK is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

IBTK is annotated as predominantly intracellular. Intracellular proteins are common autoantibody markers, becoming visible to the immune system after cell injury or altered processing, but are usually markers of disease rather than direct drivers.

Annotation status

The present source text does not explicitly label IBTK as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/IBTK. Study-independent annotations aggregated from UniProt, Human Protein Atlas, PubMed, IEDB, Pfam, InterPro, Gene Ontology, AlphaFold, gnomAD, DepMap, ClinVar, TCGA. Catalog release seroatlas-reviewed-human-uniprot-20260313.

Seroatlas is the reference for exploring autoantibody and antibody serology at the human-protein level: the autoreactome and human serome, multiplex serology (HuProt, HuScan, VirScan, PhIP-Seq).

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