The identification of a nonclassical cadherin expressed during B cell development and its interaction with surrogate light chain
The identification of a nonclassical cadherin expressed during B cell development and its interaction with surrogate light chain
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DOI：
10.1074/jbc.m005901200
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发表时间：
2000-10-06
影响因子：
4.8
通讯作者：
Melchers, F
中科院分区：
文献类型：
--
作者：
Ohnishi, K;Shimizu, T;Melchers, F
已经发现130-kDa糖蛋白（p130）与前BI细胞和前BI细胞上的替代轻链相关。利用从纯化的p130获得的肽序列，我们克隆了其基因。该基因编码典型的钙粘蛋白1型膜蛋白，具有六个胞外钙粘蛋白结构域，但在其胞质部分缺乏连环蛋白结合位点。即使没有这个连环蛋白结合位点，p130介导的钙离子依赖的细胞同型粘附。通过共转染和免疫共沉淀实验证实了p130与替代轻链的相互作用。p130在B细胞发育过程中呈双相表达。逆转录-聚合酶链反应和流式细胞术分析显示，它在B220（+）c-Kit（+）pro-B和pre-B-I细胞以及B220（+）CD 25（-）IgM（+）未成熟和成熟B细胞上表达，但在B220（+）CD 25（+）pre-B-II细胞上不表达。它也在胎儿肝脏中表达，在骨髓细胞中以低水平表达，在肠上皮细胞中强烈表达。在脾脏中，p130表达细胞主要位于边缘区。我们称之为B谱系、肠、肝和白细胞表达的基因BILL-钙粘蛋白。讨论了BILL钙粘蛋白在B细胞发育中的可能作用。
A 130-kDa glycoprotein (p130) has been found to be associated with surrogate light chain on pro- and pre-B I cells. Using peptide sequences obtained from purified p130 we have cloned its gene. The gene encodes a typical cadherin type 1 membrane protein with six extracellular cadherin domains tone pseudo domain) but lacking the catenin-binding site in its cytoplasmic part. Even without this catenin-binding site, p130 mediates Ca2+- dependent homotypic adhesion of cells. The interaction of p130 with surrogate light chain is confirmed by cotransfection and co-immunoprecipitation experiments. The expression of p130 is biphasic during the B cell development. Reverse transcriptase-polymerase chain reaction and flow cytometric analyses revealed that it is expressed on B220(+)c-Kit(+) pro-B and pre-B-I cells as well as on B220(+)CD25(-)IgM(+) immature and mature B cells but not on B220(+)CD25(+) pre-B-II cells. It is also expressed in fetal liver, at low levels in myeloid cells, and strongly in intestinal epithelial cells. In the spleen, p130-expressing cells are mainly localized in the marginal zone. We call this B lineage-, intestine-, liver- and leukocyte-expressed gene BILL-cadherin. The possible functions of BILL cadherin in B cell development are discussed.