GAPT: GRB2-Binding Adaptor Protein, Transmembrane
A transmembrane adaptor protein involved in B-cell receptor signaling and immune regulation.
Gene Information Card
| Symbol | GAPT |
|---|---|
| Full Name | GRB2-binding adaptor protein, transmembrane |
| Gene Type | protein-coding |
| Chromosomal Location | 5q11.2 |
| NCBI Gene ID | 202309 ncbi.nlm.nih.gov/gene/202309 |
| Ensembl ID | ENSG00000163513 |
| UniProt ID | Q8N257 |
| OMIM ID | 615857 |
| HGNC ID | 23312 |
| Aliases | MGC12972, bA100C15.2 |
Description
GAPT (GRB2-binding adaptor protein, transmembrane) is a protein-coding gene located on chromosome 5q11.2. It encodes a transmembrane adaptor protein that contains a GRB2-binding motif and is involved in negative regulation of B-cell receptor (BCR) signaling. GAPT is primarily expressed in lymphoid tissues and plays a role in immune cell development and function.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Immunodeficiency (potential) | Impaired BCR signaling due to GAPT loss-of-function may disrupt B-cell maturation | Limited; inferred from mouse models (PMID: 16920924) |
| B-cell lymphoma | Altered GAPT expression may contribute to aberrant B-cell proliferation | Low; expression changes observed in some lymphoma subtypes (COSMIC) |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Spleen | 12.3 | Medium |
| Lymph node | 10.8 | Medium |
| Bone marrow | 8.5 | Low |
| Blood | 6.2 | Low |
| Thymus | 5.1 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Raji (Burkitt lymphoma) | 15.2 | B-cell line, high expression |
| Daudi (Burkitt lymphoma) | 14.0 | B-cell line, high expression |
| K562 (leukemia) | 2.1 | Low expression |
| HeLa (cervical carcinoma) | 0.8 | Very low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.214C>T (p.Arg72*) | Nonsense | <0.01% | Loss of function; predicted to cause nonsense-mediated decay |
| c.389A>G (p.Tyr130Cys) | Missense | <0.01% | Unknown; may affect protein stability |
Mutation functional classification
Loss of Function (LOF)
Nonsense mutations (e.g., p.Arg72*) are predicted to result in loss of function, potentially impairing BCR signaling regulation.
Gain of Function (GOF)
No gain-of-function mutations reported.
Dominant Negative (DN)
No dominant-negative mutations reported.
View complete mutation data：
Gene Ontology (GO)
| • signal transduction (GO:0007165) | • plasma membrane (GO:0005886) |
| • signaling adaptor activity (GO:0035591) | • B cell receptor signaling pathway (GO:0042100) |
| • cytoplasm (GO:0005737) |
Pathways
• B cell receptor signaling pathway (Reactome: R-HSA-983705)
• Signaling by the B Cell Receptor (Reactome: R-HSA-983695)
Protein Summary
GAPT encodes a 267-amino-acid transmembrane adaptor protein (UniProt Q8N257) that localizes to the plasma membrane. It contains a GRB2-binding motif (YXN) and negatively regulates B-cell receptor signaling by recruiting GRB2 and modulating downstream MAPK activation. Expression is enriched in lymphoid tissues and B-cell lines.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| GAPT Knockout HEK293 Cell Line | EDJ-KQ5176 | Human | 202309 | Details Get a Quote |
| GAPT Knockout HeLa Cell Line | EDJ-KQ59031 | Human | 202309 | Details Get a Quote |
| GAPT Knockout A-549 Cell Line | EDJ-KQ67511 | Human | 202309 | Details Get a Quote |
| GAPT Knockout HCT 116 Cell Line | EDJ-KQ75908 | Human | 202309 | Details Get a Quote |
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