HLA-DPA1
HLA class II histocompatibility antigen, DP alpha 1 chain
Also known as: DPA1_HUMAN, HLA-DP1A
Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene
Protein identityUniProt · HPA
- UniProt accession
- P20036
- Gene
- HLA-DPA1
- Ensembl
- ENSG00000231389
- Chromosome
- 6
- Canonical length
- 260 aa
- Protein class
- Human disease related genes, Predicted intracellular proteins, Predicted membrane proteins
- Subcellular location
- Vesicles
- Quaternary structure
- Homotrimer
OverviewNCBI Gene
HLA-DPA1 belongs to the HLA class II alpha chain paralogues. This class II molecule is a heterodimer consisting of an alpha (DPA) and a beta (DPB) chain, both anchored in the membrane. It plays a central role in the immune system by presenting peptides derived from extracellular proteins. Class II molecules are expressed in antigen presenting cells (APC: B lymphocytes, dendritic cells, macrophages). The alpha chain is approximately 33-35 kDa and its gene contains 5 exons. Exon one encodes the leader peptide, exons 2 and 3 encode the two extracellular domains, exon 4 encodes the transmembrane domain and the cytoplasmic tail. Within the DP molecule both the alpha chain and the beta chain contain the polymorphisms specifying the peptide binding specificities, resulting in up to 4 different molecules. [provided by RefSeq, Jul 2008]
Canonical amino-acid sequenceUniProt
260 residues, UniProt reviewed canonical sequence.
>P20036|HLA-DPA1
1 MRPEDRMFHI RAVILRALSL AFLLSLRGAG AIKADHVSTY AAFVQTHRPT GEFMFEFDED
61 EMFYVDLDKK ETVWHLEEFG QAFSFEAQGG LANIAILNNN LNTLIQRSNH TQATNDPPEV
121 TVFPKEPVEL GQPNTLICHI DKFFPPVLNV TWLCNGELVT EGVAESLFLP RTDYSFHKFH
181 YLTFVPSAED FYDCRVEHWG LDQPLLKHWE AQEPIQMPET TETVLCALGL VLGLVGIIVG
241 TVLIIKSLRS GHDPRAQGTLLocalizationUniProt · AlphaFold · HPA
Whether an antibody against HLA-DPA1 can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.
- Antibody reachability
- Cell surface
- Secreted
- No
- Transmembrane segments
- 1
- Mean surface accessibility (rSASA)
- 0.4
- Highest tissue expression
- 570 nTPM
Expression across tissuesHPA
Tissue
- lymph node: 570 nTPM
- lung: 517 nTPM
- spleen: 458 nTPM
- tonsil: 325 nTPM
- appendix: 304 nTPM
- thymus: 217 nTPM
Single-cell type
- cdc: 2,886 nCPM
- macrophages: 673 nCPM
- kupffer cells: 371 nCPM
- pdcs: 314 nCPM
- b-cells: 269 nCPM
- monocytes: 262 nCPM
Immune cell
- myeloid DC: 1,726 nTPM
- intermediate monocyte: 1,069 nTPM
- memory B-cell: 818 nTPM
- naive B-cell: 800 nTPM
- total PBMC: 797 nTPM
- non-classical monocyte: 725 nTPM
Brain region
- white matter: 69 nTPM
- medulla oblongata: 51 nTPM
- hypothalamus: 49 nTPM
- spinal cord: 46 nTPM
- pons: 33 nTPM
- cerebellum: 22 nTPM
Genetic constraint and essentialitygnomAD · DepMap
Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.
- gnomAD LOEUF (loss-of-function intolerance)
- 1.57
- gnomAD pLI
- 0
- gnomAD missense Z
- 1.12
- DepMap mean gene effect
- 0.07
- DepMap dependency class
- none
OntologyGO
Biological processes
- adaptive immune response
- antigen processing and presentation of exogenous peptide antigen via MHC class II
- cellular response to type II interferon
- immune response
- peptide antigen assembly with MHC class II protein complex
- positive regulation of immune response
- positive regulation of T cell activation
- positive regulation of T cell proliferation
- positive regulation of type II interferon production
Molecular functions
Cellular components
- cell surface
- clathrin-coated endocytic vesicle membrane
- endocytic vesicle membrane
- ER to Golgi transport vesicle membrane
- Golgi membrane
- late endosome membrane
- lumenal side of endoplasmic reticulum membrane
- lysosomal membrane
- MHC class II protein complex
- plasma membrane
- trans-Golgi network membrane
- transport vesicle membrane
Protein domainsUniProt · Pfam · InterPro
- MHC class II, alpha chain, N-terminal
- Immunoglobulin/major histocompatibility complex, conserved site
- Immunoglobulin C1-set
- Immunoglobulin-like domain
- MHC classes I/II-like antigen recognition protein
- Immunoglobulin-like fold
- MHC class II, alpha/beta chain, N-terminal
- Immunoglobulin-like domain superfamily
- Major Histocompatibility Complex/Immunoglobulin
- Class II histocompatibility antigen, alpha domain
- Immunoglobulin C1-set domain
KeywordsUniProt
InteractionsUniProt · HPA
Protein binding partners of HLA-DPA1 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.
Antibody and autoantibody relevanceSeroatlas analysis
Seroatlas reads HLA-DPA1 as an antibody target. Whether an autoantibody or antibody against HLA-DPA1 could matter depends on whether native HLA-DPA1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.
HLA-DPA1 is annotated at the cell surface, where native HLA-DPA1 is exposed to circulating antibodies and is a prime autoantibody target that could block, deplete, or overstimulate it.
Annotation status
The present source text does not explicitly label HLA-DPA1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.
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