ITGA2 (Integrin Subunit Alpha 2): Gene, Function, and Clinical Significance
Comprehensive biomedical overview of the ITGA2 gene encoding the alpha-2 integrin subunit, a key mediator of cell adhesion and signaling.
Gene Information Card
| Symbol | ITGA2 |
|---|---|
| Full Name | Integrin Subunit Alpha 2 |
| Gene Type | Protein coding |
| Chromosomal Location | 5q11.2 |
| NCBI Gene ID | 3673 ncbi.nlm.nih.gov/gene/3673 |
| Ensembl ID | ENSG00000164171 |
| UniProt ID | P17301 |
| OMIM ID | 192974 |
| HGNC ID | 6137 |
| Aliases | CD49b, GPIa, VLA-2 alpha chain, BR, HPA-5 |
Description
ITGA2 encodes the integrin alpha-2 subunit, which heterodimerizes with beta-1 (ITGB1) to form the collagen receptor VLA-2 (α2β1 integrin). This receptor mediates cell adhesion to collagen and laminin, platelet aggregation, and signal transduction. ITGA2 is expressed on platelets, fibroblasts, endothelial cells, and various epithelial cells. Genetic variants in ITGA2 are associated with altered platelet function, bleeding disorders, and susceptibility to certain cancers.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Bleeding disorder, platelet-type, 16 (BDPLT16) | Loss-of-function variants impair collagen-induced platelet aggregation, leading to mild bleeding tendency. | ClinVar, OMIM #192974 |
| Thrombosis susceptibility | Polymorphisms (e.g., rs1126643, rs1801106) modulate integrin expression and platelet adhesion, influencing thrombotic risk. | NCBI Gene, PubMed |
| Colorectal cancer | ITGA2 overexpression promotes tumor cell adhesion and metastasis via collagen binding. | COSMIC, PubMed |
| Breast cancer | Altered ITGA2 expression correlates with invasive phenotype and poor prognosis. | COSMIC, PubMed |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Bone marrow | 12.5 | Medium |
| Lung | 9.8 | Medium |
| Skin | 8.2 | Medium |
| Spleen | 6.1 | Low |
| Liver | 2.3 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK 293 | 15.2 | High expression |
| A549 (lung carcinoma) | 11.4 | Moderate expression |
| MCF7 (breast cancer) | 7.8 | Low expression |
| K562 (leukemia) | 3.1 | Very low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.548G>A (p.Arg183Gln) | Missense | Rare | Reduced collagen binding; associated with BDPLT16 |
| c.802C>T (p.Arg268Cys) | Missense | Rare | Impaired integrin activation; bleeding phenotype |
| rs1126643 (c.807C>T) | Synonymous | Common (allele freq ~0.35) | Alters mRNA stability; linked to thrombosis risk |
| c.1648G>A (p.Glu550Lys) | Missense | Rare | Loss of function; platelet adhesion defect |
Mutation functional classification
Loss of Function (LOF)
Missense variants (e.g., p.Arg183Gln, p.Arg268Cys) disrupt collagen binding or integrin activation, leading to platelet adhesion defects and mild bleeding.
Gain of Function (GOF)
Not well documented; some polymorphisms may increase surface expression but not clearly gain-of-function.
Dominant Negative (DN)
No dominant-negative mutations reported for ITGA2.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Integrin signaling pathway (KEGG: hsa04510)
• ECM-receptor interaction (KEGG: hsa04512)
• Focal adhesion (KEGG: hsa04510)
• Platelet activation (KEGG: hsa04611)
Protein Summary
Integrin alpha-2 (CD49b) is a 1292-amino-acid transmembrane protein with an extracellular domain containing seven FG-GAP repeats and a von Willebrand factor A domain that mediates collagen binding. The cytoplasmic tail interacts with talin and kindlin to regulate integrin activation. As part of the α2β1 integrin, it functions as a major collagen receptor on platelets and other cells, playing critical roles in hemostasis, tissue repair, and cancer metastasis.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| ITGA2 Knockout HEK293 Cell Line | EDJ-KQ809 | Human | 3673 | Details Get a Quote |
| ITGA2B Knockout HEK293 Cell Line | EDJ-KQ810 | Human | 3674 | Details Get a Quote |
| ITGA2 Knockout HeLa Cell Line | EDJ-KQ18287 | Human | 3673 | Details Get a Quote |
| ITGA2 Knockout A-549 Cell Line | EDJ-KQ19549 | Human | 3673 | Details Get a Quote |
| ITGA2 Knockout HCT 116 Cell Line | EDJ-KQ19550 | Human | 3673 | Details Get a Quote |
| ITGA2B Knockout A-549 Cell Line | EDJ-KQ19552 | Human | 3674 | Details Get a Quote |
| ITGA2B Knockout HCT 116 Cell Line | EDJ-KQ19553 | Human | 3674 | Details Get a Quote |
| ITGA2B Knockout HeLa Cell Line | EDJ-KQ53673 | Human | 3674 | Details Get a Quote |
| ITGA2 Overexpression A-549 Stable Cell Line | EDC01491 | Human | 3673 | Details Get a Quote |
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