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LTK leukocyte receptor tyrosine kinase [ Homo sapiens (human) ]

Gene ID: 4058, updated on 7-Apr-2025

Summary

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Official Symbol
LTKprovided by HGNC
Official Full Name
leukocyte receptor tyrosine kinaseprovided by HGNC
Primary source
HGNC:HGNC:6721
See related
Ensembl:ENSG00000062524 MIM:151520; AllianceGenome:HGNC:6721
Gene type
protein coding
RefSeq status
REVIEWED
Organism
Homo sapiens
Lineage
Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; Homo
Also known as
TYK1
Summary
The protein encoded by this gene is a member of the ros/insulin receptor family of tyrosine kinases. Tyrosine-specific phosphorylation of proteins is a key to the control of diverse pathways leading to cell growth and differentiation. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Oct 2008]
Expression
Broad expression in duodenum (RPKM 6.4), lung (RPKM 6.1) and 15 other tissues See more
Orthologs
mouse all
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Genomic context

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See LTK in Genome Data Viewer
Location:
15q15.1
Exon count:
21
Annotation release Status Assembly Chr Location
RS_2024_08 current GRCh38.p14 (GCF_000001405.40) 15 NC_000015.10 (41503637..41513827, complement)
RS_2024_08 current T2T-CHM13v2.0 (GCF_009914755.1) 15 NC_060939.1 (39309799..39319984, complement)
RS_2024_09 previous assembly GRCh37.p13 (GCF_000001405.25) 15 NC_000015.9 (41795835..41806025, complement)

Chromosome 15 - NC_000015.10Genomic Context describing neighboring genes Neighboring gene RTF1 homolog, Paf1/RNA polymerase II complex component Neighboring gene uncharacterized LOC105370790 Neighboring gene ATAC-STARR-seq lymphoblastoid active region 9282 Neighboring gene Sharpr-MPRA regulatory region 6351 Neighboring gene H3K4me1 hESC enhancer GRCh37_chr15:41784974-41785474 Neighboring gene H3K4me1 hESC enhancer GRCh37_chr15:41785475-41785975 Neighboring gene ATAC-STARR-seq lymphoblastoid silent region 6359 Neighboring gene ATAC-STARR-seq lymphoblastoid silent region 6360 Neighboring gene ATAC-STARR-seq lymphoblastoid silent region 6361 Neighboring gene inositol-trisphosphate 3-kinase A Neighboring gene H3K27ac-H3K4me1 hESC enhancer GRCh37_chr15:41804857-41805604 Neighboring gene RNA polymerase II associated protein 1 Neighboring gene MPRA-validated peak2307 silencer Neighboring gene H3K27ac-H3K4me1 hESC enhancer GRCh37_chr15:41835695-41836276 Neighboring gene ReSE screen-validated silencer GRCh37_chr15:41844728-41844829 Neighboring gene elongin C pseudogene 2

Genomic regions, transcripts, and products

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Go to nucleotide: Graphics FASTA GenBank

Expression

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  • Project title: Tissue-specific circular RNA induction during human fetal development
  • Description: 35 human fetal samples from 6 tissues (3 - 7 replicates per tissue) collected between 10 and 20 weeks gestational time were sequenced using Illumina TruSeq Stranded Total RNA
  • BioProject: PRJNA270632
  • Publication: PMID 26076956
  • Analysis date: Mon Apr 2 22:54:59 2018

Bibliography

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Related articles in PubMed

  1. The ltk gene encodes a novel receptor-type protein tyrosine kinase. Krolewski JJ, et al. EMBO J, 1991 Oct. PMID 1655406, Free PMC Article
  2. Human ltk: gene structure and preferential expression in human leukemic cells. Maru Y, et al. Oncogene Res, 1990. PMID 2320375
  3. Growth and survival signals transmitted via two distinct NPXY motifs within leukocyte tyrosine kinase, an insulin receptor-related tyrosine kinase. Ueno H, et al. J Biol Chem, 1996 Nov 1. PMID 8910363
  4. Identification of the human ltk gene product in placenta and hematopoietic cell lines. Kozutsumi H, et al. Biochem Biophys Res Commun, 1993 Jan 29. PMID 8427607
  5. Differently spliced cDNAs of human leukocyte tyrosine kinase receptor tyrosine kinase predict receptor proteins with and without a tyrosine kinase domain and a soluble receptor protein. Toyoshima H, et al. Proc Natl Acad Sci U S A, 1993 Jun 15. PMID 7685902, Free PMC Article

See all (38) citations in PubMed

GeneRIFs: Gene References Into Functions

What's a GeneRIF?
  1. Spindle cell neoplasms with novel LTK fusion - Expanding the spectrum of kinase fusion-positive soft tissue tumors.
    Title: Spindle cell neoplasms with novel LTK fusion - Expanding the spectrum of kinase fusion-positive soft tissue tumors.
  2. The CLIP1-LTK fusion is an oncogenic driver in non-small-cell lung cancer.
    Title: The CLIP1-LTK fusion is an oncogenic driver in non-small-cell lung cancer.
  3. Structural basis of cytokine-mediated activation of ALK family receptors.
    Title: Structural basis of cytokine-mediated activation of ALK family receptors.
  4. LTK-to-Sec12 signaling represents the first example of an endoplasmic reticulum-resident signaling module with the potential to regulate proteostasis.
    Title: LTK is an ER-resident receptor tyrosine kinase that regulates secretion.
  5. Data show FAM150B, which was named as augmentor-alpha (AUG-alpha), binds and activtes both anaplastic lymphoma kinase (ALK) and tyrosine kinase (LTK).
    Title: Augmentor α and β (FAM150) are ligands of the receptor tyrosine kinases ALK and LTK: Hierarchy and specificity of ligand-receptor interactions.
  6. Only two related secreted factors, FAM150A and FAM150B (family with sequence similarity 150 member A and member B), stimulated LTK phosphorylation.
    Title: Deorphanization of the human leukocyte tyrosine kinase (LTK) receptor by a signaling screen of the extracellular proteome.
  7. aberrant activation of LTK may contribute to neoplastic cell growth.
    Title: ALK-activating homologous mutations in LTK induce cellular transformation.
  8. polymorphic LTKs cause up-regulation of the PI3K pathway and possibly form one genetic component of susceptibility to abnormal proliferation of self-reactive B cells in systemic lupus erythematosus
    Title: Gain-of-function polymorphism in mouse and human Ltk: implications for the pathogenesis of systemic lupus erythematosus.
Submit: New GeneRIF Correction

Phenotypes

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Find tests for this gene in the NIH Genetic Testing Registry (GTR)

Review eQTL and phenotype association data in this region using PheGenI

Variation

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See variants in ClinVar

See studies and variants in dbVar

See Variation Viewer (GRCh37.p13)

See Variation Viewer (GRCh38)

Interactions

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Products Interactant Other Gene Complex Source Pubs Description

General gene information

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Markers

Homology

Gene Ontology Provided by GOA

Function Evidence Code Pubs
enables ATP binding IEA
Inferred from Electronic Annotation
more info
  
enables kinase activity IEA
Inferred from Electronic Annotation
more info
  
enables nucleotide binding IEA
Inferred from Electronic Annotation
more info
  
enables protein binding IPI
Inferred from Physical Interaction
more info
 PubMed 
enables protein kinase activity IDA
Inferred from Direct Assay
more info
 PubMed 
enables protein kinase activity IEA
Inferred from Electronic Annotation
more info
  
enables protein tyrosine kinase activity EXP
Inferred from Experiment
more info
 PubMed 
enables protein tyrosine kinase activity IEA
Inferred from Electronic Annotation
more info
  
enables protein tyrosine kinase activity TAS
Traceable Author Statement
more info
 PubMed 
enables receptor signaling protein tyrosine kinase activator activity IDA
Inferred from Direct Assay
more info
 PubMed 
enables transferase activity IEA
Inferred from Electronic Annotation
more info
  
enables transmembrane receptor protein tyrosine kinase activity IBA
Inferred from Biological aspect of Ancestor
more info
  
enables transmembrane receptor protein tyrosine kinase activity IDA
Inferred from Direct Assay
more info
 PubMed 
enables transmembrane receptor protein tyrosine kinase activity IEA
Inferred from Electronic Annotation
more info
  
enables transmembrane receptor protein tyrosine kinase activity TAS
Traceable Author Statement
more info
 PubMed 
Process Evidence Code Pubs
involved_in cell population proliferation IDA
Inferred from Direct Assay
more info
 PubMed 
involved_in cell surface receptor protein tyrosine kinase signaling pathway IBA
Inferred from Biological aspect of Ancestor
more info
  
involved_in cell surface receptor protein tyrosine kinase signaling pathway IDA
Inferred from Direct Assay
more info
 PubMed 
involved_in cell surface receptor protein tyrosine kinase signaling pathway IEA
Inferred from Electronic Annotation
more info
  
involved_in cell surface receptor protein tyrosine kinase signaling pathway IMP
Inferred from Mutant Phenotype
more info
 PubMed 
involved_in cellular response to retinoic acid IMP
Inferred from Mutant Phenotype
more info
 PubMed 
involved_in negative regulation of apoptotic process IMP
Inferred from Mutant Phenotype
more info
 PubMed 
involved_in peptidyl-tyrosine autophosphorylation IDA
Inferred from Direct Assay
more info
 PubMed 
involved_in positive regulation of cardiac muscle cell apoptotic process IDA
Inferred from Direct Assay
more info
 PubMed 
involved_in positive regulation of neuron projection development IMP
Inferred from Mutant Phenotype
more info
 PubMed 
involved_in positive regulation of phosphatidylinositol 3-kinase/protein kinase B signal transduction IMP
Inferred from Mutant Phenotype
more info
 PubMed 
involved_in protein phosphorylation TAS
Traceable Author Statement
more info
 PubMed 
involved_in regulation of cell population proliferation IBA
Inferred from Biological aspect of Ancestor
more info
  
involved_in regulation of neuron differentiation IBA
Inferred from Biological aspect of Ancestor
more info
  
involved_in signal transduction TAS
Traceable Author Statement
more info
 PubMed 
Component Evidence Code Pubs
located_in membrane IDA
Inferred from Direct Assay
more info
 PubMed 
located_in membrane IEA
Inferred from Electronic Annotation
more info
  
is_active_in plasma membrane IBA
Inferred from Biological aspect of Ancestor
more info
  
is_active_in plasma membrane IDA
Inferred from Direct Assay
more info
 PubMed 
located_in plasma membrane IEA
Inferred from Electronic Annotation
more info
  
located_in plasma membrane TAS
Traceable Author Statement
more info
 PubMed 
part_of receptor complex IBA
Inferred from Biological aspect of Ancestor
more info
  

General protein information

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Preferred Names
leukocyte tyrosine kinase receptor
Names
protein tyrosine kinase 1
NP_001129157.1
NP_002335.2
NP_996844.1
XP_011519859.1
XP_024305687.2
XP_047288455.1
XP_047288456.1
XP_047288457.1
XP_047288458.1
XP_047288459.1
XP_047288461.1
XP_047288462.1
XP_054233880.1
XP_054233881.1
XP_054233882.1
XP_054233883.1
XP_054233884.1
XP_054233885.1
XP_054233886.1
XP_054233887.1
XP_054233888.1

NCBI Reference Sequences (RefSeq)

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RefSeqs maintained independently of Annotated Genomes

These reference sequences exist independently of genome builds. Explain

These reference sequences are curated independently of the genome annotation cycle, so their versions may not match the RefSeq versions in the current genome build. Identify version mismatches by comparing the version of the RefSeq in this section to the one reported in Genomic regions, transcripts, and products above.

mRNA and Protein(s)

  1. NM_001135685.2 → NP_001129157.1  leukocyte tyrosine kinase receptor isoform 3 precursor

    Status: REVIEWED

    Description
    Transcript Variant: This variant (3) lacks two internal coding exons and uses an alternate splice site in the central coding region, compared to variant 1. The resulting isoform (3) is missing two internal segments and has a short segment in an alternate reading frame but with the same N- and C-termini, compared to isoform 1.
    Source sequence(s)
    AC016134, AC087721, AK296892, CA394397
    Consensus CDS
    CCDS45237.1
    UniProtKB/Swiss-Prot
    P29376
    Related
    ENSP00000392196.2, ENST00000453182.2
    Conserved Domains (2) summary
    pfam07714
    Location:415 → 647
    Pkinase_Tyr; Protein tyrosine kinase
    cl21453
    Location:414 → 649
    PKc_like; Protein Kinases, catalytic domain

  2. NM_002344.6 → NP_002335.2  leukocyte tyrosine kinase receptor isoform 1 precursor

    See identical proteins and their annotated locations for NP_002335.2

    Status: REVIEWED

    Description
    Transcript Variant: This variant (1) represents the longest transcript and encodes the longest isoform (1).
    Source sequence(s)
    AC087721, AK296892, CA394397, D16105
    Consensus CDS
    CCDS10077.1
    UniProtKB/Swiss-Prot
    A6NNJ8, B4DL89, E9PFX4, P29376
    Related
    ENSP00000263800.6, ENST00000263800.11
    Conserved Domains (2) summary
    cd05036
    Location:503 → 779
    PTKc_ALK_LTK; Catalytic domain of the Protein Tyrosine Kinases, Anaplastic Lymphoma Kinase and Leukocyte Tyrosine Kinase
    pfam07714
    Location:510 → 777
    Pkinase_Tyr; Protein tyrosine kinase

  3. NM_206961.4 → NP_996844.1  leukocyte tyrosine kinase receptor isoform 2 precursor

    See identical proteins and their annotated locations for NP_996844.1

    Status: REVIEWED

    Description
    Transcript Variant: This variant (2) is lacking one of the internal coding exons compared to variant 1. This results in an isoform (2) that is missing a 61 aa segment compared to isoform 1.
    Source sequence(s)
    AC016134, AC087721, CA394397, X60702
    Consensus CDS
    CCDS10078.1
    UniProtKB/Swiss-Prot
    P29376
    Related
    ENSP00000347293.5, ENST00000355166.9
    Conserved Domains (2) summary
    cd05036
    Location:442 → 718
    PTKc_ALK_LTK; Catalytic domain of the Protein Tyrosine Kinases, Anaplastic Lymphoma Kinase and Leukocyte Tyrosine Kinase
    pfam07714
    Location:449 → 716
    Pkinase_Tyr; Protein tyrosine kinase

RefSeqs of Annotated Genomes: GCF_000001405.40-RS_2024_08

The following sections contain reference sequences that belong to a specific genome build. Explain

Reference GRCh38.p14 Primary Assembly

Genomic

  1. NC_000015.10 Reference GRCh38.p14 Primary Assembly

    Range
    41503637..41513827 complement
    Download
    GenBank, FASTA, Sequence Viewer (Graphics)

mRNA and Protein(s)

  1. XM_047432499.1 → XP_047288455.1  leukocyte tyrosine kinase receptor isoform X2

  2. XM_047432501.1 → XP_047288457.1  leukocyte tyrosine kinase receptor isoform X4

  3. XM_047432502.1 → XP_047288458.1  leukocyte tyrosine kinase receptor isoform X5

  4. XM_047432500.1 → XP_047288456.1  leukocyte tyrosine kinase receptor isoform X3

  5. XM_011521557.3 → XP_011519859.1  leukocyte tyrosine kinase receptor isoform X1

    Conserved Domains (2) summary
    cd05036
    Location:463 → 739
    PTKc_ALK_LTK; Catalytic domain of the Protein Tyrosine Kinases, Anaplastic Lymphoma Kinase and Leukocyte Tyrosine Kinase
    pfam07714
    Location:470 → 737
    Pkinase_Tyr; Protein tyrosine kinase

  6. XM_047432505.1 → XP_047288461.1  leukocyte tyrosine kinase receptor isoform X7

    UniProtKB/TrEMBL
    H3BVG6

  7. XM_024449919.2 → XP_024305687.2  leukocyte tyrosine kinase receptor isoform X6

    UniProtKB/TrEMBL
    H3BVG6

  8. XM_047432503.1 → XP_047288459.1  leukocyte tyrosine kinase receptor isoform X6

    UniProtKB/TrEMBL
    H3BVG6
    Related
    ENSP00000458111.1, ENST00000561619.5

  9. XM_047432506.1 → XP_047288462.1  leukocyte tyrosine kinase receptor isoform X8

RNA

  1. XR_007064446.1 RNA Sequence

  2. XR_007064447.1 RNA Sequence

Alternate T2T-CHM13v2.0

Genomic

  1. NC_060939.1 Alternate T2T-CHM13v2.0

    Range
    39309799..39319984 complement
    Download
    GenBank, FASTA, Sequence Viewer (Graphics)

mRNA and Protein(s)

  1. XM_054377906.1 → XP_054233881.1  leukocyte tyrosine kinase receptor isoform X2

  2. XM_054377908.1 → XP_054233883.1  leukocyte tyrosine kinase receptor isoform X4

  3. XM_054377909.1 → XP_054233884.1  leukocyte tyrosine kinase receptor isoform X5

  4. XM_054377907.1 → XP_054233882.1  leukocyte tyrosine kinase receptor isoform X3

  5. XM_054377905.1 → XP_054233880.1  leukocyte tyrosine kinase receptor isoform X1

  6. XM_054377912.1 → XP_054233887.1  leukocyte tyrosine kinase receptor isoform X7

    UniProtKB/TrEMBL
    H3BVG6

  7. XM_054377911.1 → XP_054233886.1  leukocyte tyrosine kinase receptor isoform X6

    UniProtKB/TrEMBL
    H3BVG6

  8. XM_054377910.1 → XP_054233885.1  leukocyte tyrosine kinase receptor isoform X6

    UniProtKB/TrEMBL
    H3BVG6

  9. XM_054377913.1 → XP_054233888.1  leukocyte tyrosine kinase receptor isoform X8

RNA

  1. XR_008488947.1 RNA Sequence

  2. XR_008488948.1 RNA Sequence

Nucleotide Protein
Heading Accession and Version
Protein Accession Links
GenPept Link UniProtKB Link
P29376.3 GenPept UniProtKB/Swiss-Prot:P29376

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