HLA-DOB

HLA-DOB belongs to the HLA class II beta chain paralogues. This class II molecule is a heterodimer consisting of an alpha (DOA) and a beta chain (DOB), both anchored in the membrane. It is located in intracellular vesicles. DO suppresses peptide loading of MHC class II molecules by inhibiting HLA-DM. Class II molecules are expressed in antigen presenting cells (APC: B lymphocytes, dendritic cells, macrophages). The beta chain is approximately 26-28 kDa and its gene contains 6 exons. Exon one encodes the leader peptide, exons 2 and 3 encode the two extracellular domains, exon 4 encodes the transmembrane domain and exon 5 encodes the cytoplasmic tail. [provided by RefSeq, Jul 2008]

Full Name

Major Histocompatibility Complex, Class II, DO Beta

Function

Important modulator in the HLA class II restricted antigen presentation pathway by interaction with the HLA-DM molecule in B-cells. Modifies peptide exchange activity of HLA-DM.

Biological Process

Adaptive immune response Source: UniProtKB-KW
Antigen processing and presentation of exogenous peptide antigen via MHC class II Source: GO_Central
Negative regulation of antigen processing and presentation of peptide antigen via MHC class II Source: UniProtKB
Peptide antigen assembly with MHC class II protein complex Source: GO_Central
Positive regulation of T cell activation Source: GO_Central

Cellular Location

Lysosome membrane; Endosome membrane. Complexes with HLA-DM molecule during intracellular transport and in endosomal/lysosomal compartments. Heterotetramerization is necessary to exit the ER.

Topology

Extracellular: 27-224
Helical: 225-245
Cytoplasmic: 246-273