HLA-DRB1

HLA-DRB1 belongs to the HLA class II beta chain paralogs. The class II molecule is a heterodimer consisting of an alpha (DRA) and a beta chain (DRB), 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. The beta chain is approximately 26-28 kDa. It is encoded by 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. Within the DR molecule the beta chain contains all the polymorphisms specifying the peptide binding specificities. Hundreds of DRB1 alleles have been described and some alleles have increased frequencies associated with certain diseases or conditions. For example, DRB1*1302 has been related to acute and chronic hepatitis B virus persistence. There are multiple pseudogenes of this gene. [provided by RefSeq, Jul 2020]

HLA-DRB1属于HLA II类β链同源物。II类分子由一个α链（DRA）和一个β链（DRB）组成的异源二聚体，两者均锚定于膜上。其在免疫系统中的作用至关重要，通过呈现由细胞外蛋白衍生的肽段。II类分子在抗原呈递细胞中表达。β链的分子量约为26-28 kDa，由6个外显子编码。外显子一编码引导肽；外显子二和外显子三编码两个细胞外结构域；外显子四编码跨膜结构域；外显子五编码细胞质尾。在DR分子中，β链包含所有指定肽段结合特异性的多态性。已描述了数百个DRB1等位基因，其中某些等位基因与某些疾病或条件相关的增加频率有关。例如，DRB1*1302与乙型肝炎病毒急性或慢性持续感染有关。该基因存在多个假基因。[由RefSeq提供，2020年7月]