Reid R A, Bronson D D, Young K M, Hemperly J J
Becton Dickinson and Company Research Center, Research Triangle Park, NC 27709.
Brain Res Mol Brain Res. 1994 Jan;21(1-2):1-8. doi: 10.1016/0169-328x(94)90372-7.
We have prepared a monoclonal antibody, Neuro-1, that recognizes the human homolog of the chicken contactin/F11 and mouse F3 cell adhesion molecules. The Neuro-1 antigen, structurally characterized as a 135 kDa glycosylphosphatidylinositol-linked glycoprotein, was immunoaffinity purified and partially sequenced. Comparison of an internal peptide sequence to that predicted from the chicken contactin/F11, mouse F3 and human contactin (reported herein) cDNA sequence identifies the Neuro-1 antigen as human contactin. Moreover, a polyclonal antisera generated against the purified Neuro-1 antigen was immunoreactive with a fragment of human contactin expressed in bacteria. The complete coding and deduced amino acid sequences of human contactin were determined and are 86% and 95% identical to the respective mouse F3 sequences. Structural features shared with contactin/F11/F3 include six immunoglobulin type C2 and four fibronectin type III-like domains, multiple sites for asn-linked glycosylation and a COOH-terminal signal peptide presumably removed during the generation of a phosphatidylinositol cell surface linkage. The potential for glycosylation and GPI-linkage is also consistent with protein chemical studies of human contactin. Contactin mRNA expression was characterized using Northern blot analyses of human tissues and cell lines. High level expression of a single contactin transcript in adult brain, and low level expression of multiple transcripts in lung, pancreas, kidney and skeletal muscle are observed. Highly expressed multiple transcripts, similar in pattern to that of pancreas, lung, kidney and skeletal muscle, are also observed in human neuroblastoma and retinoblastoma cell lines.
我们制备了一种单克隆抗体Neuro-1，它可识别鸡contactin/F11和小鼠F3细胞粘附分子的人类同源物。Neuro-1抗原在结构上被表征为一种135 kDa的糖基磷脂酰肌醇连接糖蛋白，通过免疫亲和纯化并进行了部分测序。将内部肽序列与从鸡contactin/F11、小鼠F3和人类contactin（本文报道）cDNA序列预测的序列进行比较，确定Neuro-1抗原为人类contactin。此外，针对纯化的Neuro-1抗原产生的多克隆抗血清与在细菌中表达的人类contactin片段具有免疫反应性。确定了人类contactin的完整编码和推导氨基酸序列，它们与相应的小鼠F3序列分别有86%和95%的同一性。与contactin/F11/F3共有的结构特征包括六个免疫球蛋白C2型结构域和四个纤连蛋白III型样结构域、多个天冬酰胺连接的糖基化位点以及一个COOH末端信号肽，推测在磷脂酰肌醇细胞表面连接的形成过程中被去除。糖基化和GPI连接的可能性也与人类contactin的蛋白质化学研究一致。使用人类组织和细胞系的Northern印迹分析对contactin mRNA表达进行了表征。观察到在成人大脑中单一contactin转录本的高水平表达，以及在肺、胰腺、肾脏和骨骼肌中多个转录本的低水平表达。在人类神经母细胞瘤和视网膜母细胞瘤细胞系中也观察到高度表达的多个转录本，其模式与胰腺、肺、肾脏和骨骼肌中的相似。
