B淋巴细胞抗原CD19 (B淋巴细胞表面抗原B4) (分化抗原CD19) (T细胞表面抗原Leu-12) (CD抗原CD19)
B淋巴细胞抗原CD19 (B淋巴细胞表面抗原B4) (分化抗原CD19) (T细胞表面抗原Leu-12) (CD抗原CD19)
P15391功能描述
Functions as a coreceptor for the B-cell antigen receptor complex (BCR) on B-lymphocytes (PubMed:29523808). Decreases the threshold for activation of downstream signaling pathways and for triggering B-cell responses to antigens (PubMed:1373518, PubMed:16672701, PubMed:2463100). Activates signaling pathways that lead to the activation of phosphatidylinositol 3-kinase and the mobilization of intracellular Ca(2+) stores (PubMed:12387743, PubMed:16672701, PubMed:9317126, PubMed:9382888). Is not required for early steps during B cell differentiation in the blood marrow (PubMed:9317126). Required for normal differentiation of B-1 cells (By similarity). Required for normal B cell differentiation and proliferation in response to antigen challenges (PubMed:1373518, PubMed:2463100). Required for normal levels of serum immunoglobulins, and for production of high-affinity antibodies in response to antigen challenge (PubMed:12387743, PubMed:16672701, PubMed:9317126). {ECO:0000250|UniProtKB:P25918, ECO:0000269|PubMed:12387743, ECO:0000269|PubMed:1373518, ECO:0000269|PubMed:16672701, ECO:0000269|PubMed:2463100, ECO:0000269|PubMed:29523808, ECO:0000269|PubMed:9317126, ECO:0000269|PubMed:9382888}. FUNCTION: 作为B淋巴细胞上B细胞抗原受体复合物(BCR)的共受体发挥作用 (PubMed:29523808)。降低下游信号通路激活以及触发B细胞对抗原应答的阈值 (PubMed:1373518, PubMed:16672701, PubMed:2463100)。激活导致磷酸肌醇3-激酶活化和细胞内Ca(2+)库动员的信号通路 (PubMed:12387743, PubMed:16672701, PubMed:9317126, PubMed:9382888)。对于骨髓中B细胞分化的早期步骤并非必需 (PubMed:9317126)。B-1细胞的正常分化所必需 (By similarity)。对抗原刺激产生应答的正常B细胞分化和增殖所必需 (PubMed:1373518, PubMed:2463100)。对于正常水平的血清免疫球蛋白以及对抗原刺激产生高亲和力抗体是必需的 (PubMed:12387743, PubMed:16672701, PubMed:9317126)。 {ECO:0000250|UniProtKB:P25918, ECO:0000269|PubMed:12387743, ECO:0000269|PubMed:1373518, ECO:0000269|PubMed:16672701, ECO:0000269|PubMed:2463100, ECO:0000269|PubMed:29523808, ECO:0000269|PubMed:9317126, ECO:0000269|PubMed:9382888}.
组织特异性
Detected on marginal zone and germinal center B cells in lymph nodes (PubMed:2463100). Detected on blood B cells (at protein level) (PubMed:16672701, PubMed:2463100).
亚细胞定位
Cell membrane
关键词