TXK
Tyrosine-protein kinase TXK
Also known as: BTKL, PSCTK5, PTK4, RLK, TKL, TXK_HUMAN
Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene
Protein identityUniProt · HPA
- UniProt accession
- P42681
- Gene
- TXK
- Ensembl
- ENSG00000074966
- Chromosome
- 4
- Canonical length
- 527 aa
- Protein class
- Enzymes, Predicted intracellular proteins
- Subcellular location
- Nucleoplasm,Nucleoli,Plasma membrane,Cytosol
OverviewNCBI Gene
Predicted to enable non-membrane spanning protein tyrosine kinase activity. Involved in positive regulation of macromolecule biosynthetic process; positive regulation of type II interferon-mediated signaling pathway; and protein autophosphorylation. Located in cytosol; nuclear lumen; and plasma membrane. [provided by Alliance of Genome Resources, Jul 2025]
Canonical amino-acid sequenceUniProt
527 residues, UniProt reviewed canonical sequence.
>P42681|TXK
1 MILSSYNTIQ SVFCCCCCCS VQKRQMRTQI SLSTDEELPE KYTQRRRPWL SQLSNKKQSN
61 TGRVQPSKRK PLPPLPPSEV AEEKIQVKAL YDFLPREPCN LALRRAEEYL ILEKYNPHWW
121 KARDRLGNEG LIPSNYVTEN KITNLEIYEW YHRNITRNQA EHLLRQESKE GAFIVRDSRH
181 LGSYTISVFM GARRSTEAAI KHYQIKKNDS GQWYVAERHA FQSIPELIWY HQHNAAGLMT
241 RLRYPVGLMG SCLPATAGFS YEKWEIDPSE LAFIKEIGSG QFGVVHLGEW RSHIQVAIKA
301 INEGSMSEED FIEEAKVMMK LSHSKLVQLY GVCIQRKPLY IVTEFMENGC LLNYLRENKG
361 KLRKEMLLSV CQDICEGMEY LERNGYIHRD LAARNCLVSS TCIVKISDFG MTRYVLDDEY
421 VSSFGAKFPI KWSPPEVFLF NKYSSKSDVW SFGVLMWEVF TEGKMPFENK SNLQVVEAIS
481 EGFRLYRPHL APMSIYEVMY SCWHEKPEGR PTFAELLRAV TEIAETWLocalizationUniProt · AlphaFold · HPA
Whether an antibody against TXK 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
- Cell surface
- Secreted
- No
- Transmembrane segments
- 0
- Mean surface accessibility (rSASA)
- 0.31
- Highest tissue expression
- 14 nTPM
Expression across tissuesHPA
Tissue
- lymph node: 14 nTPM
- tonsil: 9.9 nTPM
- spleen: 8.7 nTPM
- epididymis: 7.9 nTPM
- appendix: 7 nTPM
- small intestine: 5.2 nTPM
Single-cell type
- nk-cells: 792 nCPM
- innate lymphoid cells: 491 nCPM
- thymocytes: 468 nCPM
- t-cells: 216 nCPM
- hematopoietic stem cells: 199 nCPM
- retinal ganglion cells: 155 nCPM
Immune cell
- NK-cell: 119 nTPM
- naive CD4 T-cell: 50 nTPM
- MAIT T-cell: 44 nTPM
- naive CD8 T-cell: 34 nTPM
- total PBMC: 29 nTPM
- gdT-cell: 28 nTPM
Brain region
- pons: 2.2 nTPM
- thalamus: 1.2 nTPM
- medulla oblongata: 1.1 nTPM
- cerebral cortex: 0.9 nTPM
- hypothalamus: 0.9 nTPM
- choroid plexus: 0.8 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)
- 0.78
- gnomAD pLI
- 0
- gnomAD missense Z
- 0.92
- DepMap mean gene effect
- -0.07
- DepMap dependency class
- selective
Cancer expressionTCGA
Across TCGA tumor cohorts, this protein is over-expressed in roughly 3% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).
OntologyGO
Biological processes
- adaptive immune response
- positive regulation of cytokine production
- positive regulation of transcription by RNA polymerase II
- positive regulation of type II interferon production
- positive regulation of type II interferon-mediated signaling pathway
- protein autophosphorylation
- protein phosphorylation
- regulation of gene expression
- T cell receptor signaling pathway
Molecular functions
Cellular components
Protein domainsUniProt · Pfam · InterPro
- Protein kinase domain
- SH2 domain
- Serine-threonine/tyrosine-protein kinase, catalytic domain
- SH3 domain
- Tyrosine-protein kinase, active site
- Protein kinase-like domain superfamily
- Protein kinase, ATP binding site
- Tyrosine-protein kinase, catalytic domain
- SH3-like domain superfamily
- SH2 domain superfamily
- Non-receptor tyrosine kinases involved in cell signaling
- SH2 domain
- SH3 domain
- Protein tyrosine and serine/threonine kinase
- Tyrosine-protein kinase TXK, SH3 domain
- Tyrosine-protein kinase TXK, SH2 domain
KeywordsUniProt
InteractionsUniProt · HPA
Protein binding partners of TXK 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 TXK as an antibody target. Whether an autoantibody or antibody against TXK could matter depends on whether native TXK is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.
TXK is annotated at the cell surface, where native TXK is exposed to circulating antibodies and is a prime autoantibody target that could block, deplete, or overstimulate it.
Annotation status
The present source text does not explicitly label TXK as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.
Loading the interactive Seroatlas protein explorer...