Miura R, Ethell I M, Yamaguchi Y
The Burnham Institute, La Jolla, California 92037, USA.
J Neurochem. 2001 Jan;76(2):413-24. doi: 10.1046/j.1471-4159.2001.00042.x.
Lecticans, a family of chondroitin sulfate proteoglycans, represent the largest group of proteoglycans expressed in the nervous system. We previously showed that the C-type lectin domains of lecticans bind two classes of sulfated cell surface glycolipids, sulfatides and HNK-1-reactive sulfoglucuronylglycolipids (SGGLs). In this paper, we demonstrate that the interaction between the lectin domain of brevican, a nervous system-specific lectican, and cell surface SGGLs acts as a novel cell recognition system that promotes neuronal adhesion and neurite outgrowth. The Ig chimera of the brevican lectin domain bind to the surface of SGGL-expressing rat hippocampal neurons. The substrate of the brevican chimera promotes adhesion and neurite outgrowth of hippocampal neurons. The authentic, full-length brevican also promotes neuronal cell adhesion and neurite outgrowth. These activities of brevican substrates are neutralized by preincubation of cells with HNK-1 monoclonal antibodies and by pretreatment of the brevican substrates with purified SGGLs. Brevican and HNK-1 carbohydrates are coexpressed in specific layers of the developing hippocampus where axons from entorhinal neurons elongate. Our observations suggest that cell surface SGGLs and extracellular lecticans comprise a novel cell-substrate recognition system operating in the developing nervous system.
凝集素是硫酸软骨素蛋白聚糖家族的成员，是神经系统中表达的最大的蛋白聚糖群体。我们之前表明，凝集素的C型凝集素结构域结合两类硫酸化细胞表面糖脂，硫苷脂和HNK-1反应性硫酸葡萄糖醛酸糖脂（SGGLs）。在本文中，我们证明了神经系统特异性凝集素短蛋白聚糖的凝集素结构域与细胞表面SGGLs之间的相互作用作为一种新型细胞识别系统，促进神经元粘附和神经突生长。短蛋白聚糖凝集素结构域的Ig嵌合体与表达SGGL的大鼠海马神经元表面结合。短蛋白聚糖嵌合体的底物促进海马神经元的粘附和神经突生长。真实的全长短蛋白聚糖也促进神经元细胞粘附和神经突生长。短蛋白聚糖底物的这些活性通过用HNK-1单克隆抗体预孵育细胞以及用纯化的SGGLs预处理短蛋白聚糖底物而被中和。短蛋白聚糖和HNK-1碳水化合物在来自内嗅神经元的轴突伸长的发育中的海马体的特定层中共表达。我们的观察结果表明，细胞表面SGGLs和细胞外凝集素构成了在发育中的神经系统中起作用一种新型细胞 - 底物识别系统。
