TRA: T Cell Receptor Alpha Locus
Key component of the adaptive immune system, encoding the alpha chain of the T cell receptor
Gene Information Card
| Symbol | TRA |
|---|---|
| Full Name | T cell receptor alpha locus |
| Gene Type | protein-coding (locus) |
| Chromosomal Location | 14q11.2 |
| NCBI Gene ID | 6955 ncbi.nlm.nih.gov/gene/6955 |
| Ensembl ID | ENSG00000211829 |
| UniProt ID | P01848 (TCRA_HUMAN) |
| OMIM ID | 186880 |
| HGNC ID | 12027 |
| Aliases | TCRA, TCRD, TRA@, TRAC, TRD@ |
Description
The TRA locus encodes the alpha chain of the T cell receptor (TCR), a heterodimeric membrane protein responsible for recognizing antigens presented by major histocompatibility complex (MHC) molecules. The locus undergoes V(D)J recombination to generate diverse TCR alpha chains, essential for adaptive immune responses. TRA is located on chromosome 14q11.2 and includes variable (V), joining (J), and constant (C) gene segments.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| T-cell acute lymphoblastic leukemia (T-ALL) | Chromosomal rearrangements involving TRA (e.g., translocations with LMO2, TAL1) lead to aberrant T cell proliferation. | PMID: 10655551, COSMIC |
| Severe combined immunodeficiency (SCID) | Defects in V(D)J recombination or TRA locus deletions impair T cell development. | OMIM #186880, ClinVar |
| Autoimmune lymphoproliferative syndrome (ALPS) | Somatic mutations in TRA can disrupt TCR signaling and apoptosis. | PMID: 24665063 |
| Immunodeficiency with hyper-IgM type 1 | Rare TRA deletions affecting class switch recombination. | OMIM #308230 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Lymph node | 12.5 | High |
| Spleen | 10.8 | High |
| Thymus | 8.2 | High |
| Bone marrow | 4.1 | Medium |
| Blood | 3.5 | Medium |
| Lung | 0.2 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Jurkat (T-cell leukemia) | 15.3 | High expression; used in TCR studies |
| MOLT-4 (T-cell lymphoblast) | 12.1 | High expression |
| K-562 (erythroleukemia) | 0.1 | No significant expression |
| HeLa (cervical carcinoma) | 0.0 | No expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| TRA::LMO2 fusion | Translocation | <1% in T-ALL | Oncogenic; drives T-cell leukemia |
| TRA::TAL1 fusion | Translocation | ~3% in T-ALL | Oncogenic; aberrant TAL1 expression |
| TRA deletion (homozygous) | Deletion | Rare | Loss of TCR alpha chain; causes SCID |
| Somatic missense (e.g., p.Gly123Arg) | Missense | <0.1% in ALPS | Impaired TCR signaling |
Mutation functional classification
Loss of Function (LOF)
Homozygous deletions or nonsense mutations in TRA cause complete loss of TCR alpha chain, leading to severe combined immunodeficiency (SCID) due to impaired T cell development.
Gain of Function (GOF)
Chromosomal translocations (e.g., TRA::LMO2) result in ectopic expression of oncogenes, promoting T-cell acute lymphoblastic leukemia (T-ALL).
Dominant Negative (DN)
Somatic missense mutations in the constant region can produce non-functional TCR alpha chains that interfere with wild-type TCR assembly, contributing to autoimmune lymphoproliferative syndrome (ALPS).
View complete mutation data：
Gene Ontology (GO)
Pathways
• T cell receptor signaling pathway (KEGG hsa04660)
• Th1 and Th2 cell differentiation (KEGG hsa04658)
• PD-1 checkpoint pathway in cancer (Reactome R-HSA-389948)
• Costimulation by the CD28 family (Reactome R-HSA-388841)
Protein Summary
The T cell receptor alpha chain (UniProt P01848) is a type I transmembrane glycoprotein of approximately 28 kDa. It pairs with the TCR beta chain to form the heterodimeric TCR, which recognizes peptide-MHC complexes. The alpha chain contains variable (V) and constant (C) domains, with the V domain determining antigen specificity. The cytoplasmic tail is short and associates with CD3 signaling subunits. TRA is essential for T cell development and adaptive immunity.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| TRAPPC2 Knockout HeLa Cell Line | EDJ-KQ27 | Human | 6399 | Details Get a Quote |
| TRAF6 Knockout HEK293 Cell Line | EDJ-KQ107 | Human | 7189 | Details Get a Quote |
| TRADD Knockout HEK293 Cell Line | EDJ-KQ598 | Human | 8717 | Details Get a Quote |
| TRAF1 Knockout HEK293 Cell Line | EDJ-KQ600 | Human | 7185 | Details Get a Quote |
| TRAF2 Knockout HEK293 Cell Line | EDJ-KQ601 | Human | 7186 | Details Get a Quote |
| TRAF3 Knockout HEK293 Cell Line | EDJ-KQ602 | Human | 7187 | Details Get a Quote |
| TRAF5 Knockout HEK293 Cell Line | EDJ-KQ603 | Human | 7188 | Details Get a Quote |
| TRABD Knockout HEK293 Cell Line | EDJ-KQ2251 | Human | 80305 | Details Get a Quote |
| TRAM1 Knockout HEK293 Cell Line | EDJ-KQ2399 | Human | 23471 | Details Get a Quote |
| TRAF7 Knockout HEK293 Cell Line | EDJ-KQ3267 | Human | 84231 | Details Get a Quote |
| TRANK1 Knockout HEK293 Cell Line | EDJ-KQ3309 | Human | 9881 | Details Get a Quote |
| TRAFD1 Knockout HEK293 Cell Line | EDJ-KQ3319 | Human | 10906 | Details Get a Quote |
| TRA2B Knockout HEK293 Cell Line | EDJ-KQ5738 | Human | 6434 | Details Get a Quote |
| TRA Knockout HEK293 Cell Line | EDJ-KQ5906 | Human | 6955 | Details Get a Quote |
| TRAPPC10 Knockout HEK293 Cell Line | EDJ-KQ5950 | Human | 7109 | Details Get a Quote |
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