HLA-DPA1
Major Histocompatibility Complex, Class II, DP Alpha 1
Gene Information Card
| Symbol | HLA-DPA1 |
|---|---|
| Full Name | Major Histocompatibility Complex, Class II, DP Alpha 1 |
| Gene Type | Protein coding |
| Chromosomal Location | 6p21.32 |
| NCBI Gene ID | 3113 ncbi.nlm.nih.gov/gene/3113 |
| Ensembl ID | ENSG00000231389 |
| UniProt ID | P20036 |
| OMIM ID | 142880 |
| HGNC ID | 4938 |
| Aliases | HLA-DP1A, HLADP, HLA-DPA, DP(W3), HLA-DP alpha chain |
Description
HLA-DPA1 encodes the alpha chain of the HLA-DP heterodimer, a classical MHC class II molecule expressed on antigen-presenting cells. It plays a critical role in the immune system by presenting foreign peptides to CD4+ T cells, thereby initiating adaptive immune responses. Polymorphisms in HLA-DPA1 are associated with susceptibility to autoimmune diseases and infectious diseases.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Rheumatoid arthritis | HLA-DPA1 variants alter peptide binding, influencing T-cell activation and autoimmunity | OMIM 180300 |
| Hepatitis B virus infection | Specific HLA-DPA1 alleles affect viral antigen presentation and clearance | PMID 22470476 |
| Type 1 diabetes | HLA-DPA1 polymorphisms contribute to MHC class II-mediated beta-cell autoimmunity | OMIM 222100 |
| Celiac disease | HLA-DPA1-DPB1 haplotypes modulate gluten peptide presentation | PMID 20190752 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Lymph node | 12.5 | Medium |
| Spleen | 10.8 | Medium |
| Lung | 6.2 | Low |
| Small intestine | 5.1 | Low |
| Whole blood | 4.3 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| B-lymphocyte (GM12878) | 15.2 | High expression |
| Monocyte (THP-1) | 8.7 | Medium expression |
| Dendritic cell (immature) | 20.1 | High expression |
| HeLa | 0.5 | Very low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| rs3077 | SNP (intronic) | 0.35 (East Asian) | Associated with HBV clearance |
| rs9277535 | SNP (3' UTR) | 0.28 (European) | Linked to HLA-DP expression levels and autoimmune risk |
| c.224G>A (p.Arg75His) | Missense | <0.01 | Alters peptide-binding groove; potential impact on antigen presentation |
Mutation functional classification
Loss of Function (LOF)
No confirmed loss-of-function mutations reported in HLA-DPA1; complete loss likely lethal due to immune deficiency.
Gain of Function (GOF)
Not described; altered peptide binding may enhance presentation of self-antigens.
Dominant Negative (DN)
Not reported; heterodimer with HLA-DPB1 may be affected by rare missense variants.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Antigen processing and presentation (KEGG hsa04612)
• Allograft rejection (KEGG hsa05330)
• Graft-versus-host disease (KEGG hsa05332)
• Type I diabetes mellitus (KEGG hsa04940)
Protein Summary
HLA-DPA1 is a 260-amino-acid protein that forms the alpha chain of the HLA-DP heterodimer. It contains an extracellular alpha-1 and alpha-2 domain, a transmembrane region, and a short cytoplasmic tail. The alpha-1 domain contributes to the peptide-binding groove, which accommodates peptides of 9-25 residues. The protein is highly polymorphic, with over 100 alleles, enabling diverse antigen presentation. It is expressed primarily on professional antigen-presenting cells such as dendritic cells, macrophages, and B cells.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| HLA-DPA1 Knockout HEK293 Cell Line | EDJ-KQ4872 | Human | 3113 | Details Get a Quote |
| HLA-DPA1 Knockout HeLa Cell Line | EDJ-KQ27661 | Human | 3113 | Details Get a Quote |
| HLA-DPA1 Knockout A-549 Cell Line | EDJ-KQ61991 | Human | 3113 | Details Get a Quote |
| HLA-DPA1 Knockout HCT 116 Cell Line | EDJ-KQ70473 | Human | 3113 | Details Get a Quote |
