LYMPHOCYTE-B LINEAGE-RESTRICTED EXPRESSION OF MB-1, A GENE WITH CD3-LIKE STRUCTURAL-PROPERTIES
LYMPHOCYTE-B LINEAGE-RESTRICTED EXPRESSION OF MB-1, A GENE WITH CD3-LIKE STRUCTURAL-PROPERTIES
复制标题
DOI：
10.1002/j.1460-2075.1988.tb03220.x
复制
发表时间：
1988-11-01
期刊：
影响因子：
11.4
通讯作者：
MELCHERS, F
中科院分区：
文献类型：
--
作者：
SAKAGUCHI, N;KASHIWAMURA, S;MELCHERS, F
一个名为m-mb-1的基因是从小鼠前B-阴性T淋巴细胞消减文库中分离出来的。在B系早期祖细胞、前B系细胞系和成熟B系细胞系、正常静息B淋巴细胞和多克隆激活的B细胞母细胞中，发现它以低到中等丰度的形式表达。该基因在浆细胞瘤、单核/巨噬细胞、T淋巴细胞或成纤维细胞系中不表达，在胸腺、肝脏、心脏、肾脏、肺或脑中也不表达。M-mb-1基因的核苷酸序列编码一个由220个氨基酸组成的膜糖蛋白，它包括一个前导序列、一个具有两个潜在N-糖基化位点的胞外区、一个跨膜区和一个可能的胞内区。人类同源物h-mb-1的部分序列在核苷酸和氨基酸序列上与假定的细胞质内结构域的小鼠形式有近90%的同源性。针对m-mb-1与蛋白a的融合蛋白产生的抗体，亲和纯化的m-mb-1特异性，在其表面染色前B细胞和成熟B细胞，但不染色T细胞和成纤维细胞。针对假定的细胞内域的20个氨基酸的延伸产生的抗体，在小鼠和人类蛋白之间具有90%的同源性，没有对任何被测试的细胞系的表面进行染色。然而，它们对Pre-B和B细胞系的细胞质进行了染色，但对浆细胞瘤、T细胞系或成纤维细胞却没有。MB-1被认为是B系细胞上CD3样复合体的潜在成员，因为推导出的蛋白质的总体结构以及小鼠和人类之间的同源性与伽马显示出惊人的相似之处。和.德尔塔。T细胞上表达的CD3复合体的链。
A gene, called m-mb-1, was isolated from a murine pre-B-minus T lymphocyte subtracted library. It was found expressed as mRNA at low to medium abundance in early progenitors of the B lineage, in pre-B and mature B lineage cell lines, in normal resting B lymphocytes and in polyclonally activated B cell blasts. The gene was not expressed in plasmacytomas, in cell lines of the monocyte/macrophage, the T lymphocyte or the fibroblast lineages, nor in thymus, liver, heart, kidney, lung or brain. The nucleotide sequence of the m-mb-1 gene encodes a putative membrane glycoprotein with 220 amino acids, which includes a leader sequence, a putative extracellular domain with two potential N-glycosylation sites, a transmembrane portion and a putative intracellular domain. The partial sequence of a human homologue, h-mb-1, shows nearly 90% homology in nucleotide as well as amino acid sequences to the murine form of a stretch of the putative intracytoplasmic domain. Antibodies raised against a fusion protein of m-mb-1 with protein a, affinity purified for their m-mb-1 specificity, stained pre-B and mature B cell lines on their surface, but did not stain T cell lines and fibroblasts. Antibodies raised against a stretch of 20 amino acids of the putative intracellular domain with 90% homology between the mouse and human protein did not stain the surface of any cell lines tested. However, they stained the cytoplasm pre-B and B cell lines, but not of plasmacytomas, T cell lines or fibroblasts. mb-1 is discussed as a potential member of a CD3-like complex on cells of the B lineage, since the overall structure of the deduced protein and the homologies between the murine and the human form show striking similarities to the .gamma. and .delta. chains of the CD3 complex expressed on T cells.