Deleted in colorectal carcinoma (DCC) binds heparin via its fifth fibronectin type III domain
Deleted in colorectal carcinoma (DCC) binds heparin via its fifth fibronectin type III domain
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DOI：
10.1074/jbc.272.43.26940
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发表时间：
1997-10-24
影响因子：
4.8
通讯作者：
Linsley, PS
中科院分区：
文献类型：
--
作者：
Bennett, KL;Bradshaw, J;Linsley, PS
DCC（deleted in colorectal carcinoma）是一种广泛表达的细胞表面受体。Netrin-1最近被鉴定为脑中的DCC配体，但通过发现抗DCC抗体（克隆AF 5）中和netrin-1依赖性连合轴突生长而不阻断DCC/netrin-1相互作用，提出了其他DCC配体的可能性。在这里，我们已经寻找替代细胞表面DCC配体。DCC-Ig融合蛋白与神经和上皮来源的细胞系结合，表明这些细胞系表达DCC的配体。细胞表面结合活性由第五纤连蛋白III型重复FNIII-D5的β链F和G之间的环介导。该环包括序列KNRR，其类似于其他蛋白质中的肝素结合基序。肝素酶和肝素酶处理细胞减少了DCC-Ig的结合，表明硫酸乙酰肝素蛋白聚糖是细胞表面DCC配体。肝素阻断实验和DCC-Ig与固定化硫酸乙酰肝素的结合进一步支持了这一点。细胞表面和固定在塑料上的DCC-Ig和硫酸乙酰肝素/肝素之间的相互作用被阻断netrin-1依赖性连合轴突生长的相同抗DCC抗体阻断。综上所述，这些结果表明，DCC-Ig/肝素相互作用可能有助于DCC的生物活性。
DCC (deleted in colorectal carcinoma) is a broadly expressed cell-surface receptor. Netrin-1 was recently identified as a DCC ligand in brain, but the possibility of other DCC ligands was suggested by the finding that an anti-DCC antibody (clone AF5) neutralized netrin-1-dependent commissural axon outgrowth without blocking DCC/netrin-1 interactions. Here we have searched for alternative cell-surface DCC ligands. A DCC-Ig fusion protein bound to neural and epithelial derived cell lines, indicating that these lines express ligand(s) for DCC. The cell-surface binding activity was mediated by the loop between beta-strands F and G of the fifth fibronectin type III repeat FNIII-D5. The loop included the sequence KNRR, which resembles heparin-binding motifs in other proteins. Heparinase and heparitinase treatment of cells reduced binding of DCC-Ig, suggesting that heparan sulfate proteoglycans are cell-surface DCC ligand(s). This was further supported by heparin blocking experiments and by binding of DCC-Ig to immobilized heparan sulfate. The interaction between DCC-Ig and heparan sulfate/heparin, both on the surface of cells and immobilized on plastic, was blocked by the same anti-DCC antibody that blocks netrin-1-dependent commissural axon outgrowth. Taken together, these findings suggest that the DCC-Ig/heparin interaction may contribute to the biological activity to DCC.