protein 蛋白质 CD19 molecule CD19 分子 A protein that is a translation product of the human CD19 gene or a 1:1 ortholog thereof. It is composed of an N-terminal extracellular domain containing two Ig-like C2-type (immunoglobulin-like) domains, followed by a single-pass transmembrane segment and a cytoplasmic C-terminal tail. CD19 expression is restricted to members of the B cell lineage. It functions as a co-receptor for B-cell antigen receptor (BCR), regulating signal transduction. B-lymphocyte surface antigen B4 CD19 Category=gene. Requested by=CL. PIRSF:PIRSF016630 PR:000001002 T-cell surface antigen Leu-12 differentiation antigen CD19 protein B淋巴细胞表面抗原B4 T细胞表面抗原Leu-12 分化抗原CD19 是人CD19基因或其1:1直系同源物的翻译产物的蛋白质。它由包含两个Ig样C2型（免疫球蛋白样）结构域的N-末端胞外结构域组成，紧随着一个单次跨膜片段和一个胞质C-末端尾片。 CD19表达限于B细胞谱系的成员。它作为B细胞抗原受体（BCR）的共同受体，调节着信号转导。