Structures and functions of gicerin, a novel cell adhesion molecule.

我们报道了诱导鸡睫状神经元神经突生长的神经突生长因子（neurite outgrowth factor， NOF），发现它是一种细胞外基质蛋白，属于层粘连蛋白家族。另一方面，我们已经分离出一种NOF受体，它是一种属于免疫球蛋白超家族的细胞粘附分子。黄芩苷具有嗜同性和嗜异性的细胞粘附活性。黄芩苷有两种异构体（和L-），它们在细胞质结构域的长度不同。Gicerin仅在神经系统发育的突触发生和细胞运动过程中表达，随后迅速减少。我们还发现吉黄素参与肾小管和支气管的小管形成。Gicerin也在嗅球和C6胶质瘤细胞中表达。我们发现，舌下神经横断后7-14天，损伤神经元和反应性星形胶质细胞中甘糖苷的表达不受调节。这表明，甘黄素参与了反应性星形胶质细胞的网络形成，也参与了神经末梢的神经突生长。

We have reported the neurite outgrowth factor (NOF) that induces the neurite outgrowth from chicken ciliary neurons and revealed that it is an extracellular matrix protein which belongs to laminin family. On the other hand, we have isolated gicerin as a NOF receptor, which is a cell adhesion molecule belonging to a immunoglobulin superfamily. Gicerin exhibits both homophilic and heterophilic cell adhesion activities. Gicerin has two isomers (S-and L-) which differ in the length of cytoplasmic domain. Gicerin is expressed only during synaptogenesis and cell movement in development nervous system and thereafter rapidly is decreased. We also found that gicerin is involved in the tubular formation in the renal tubules and bronchus. Gicerin is also expressed in the olfactory bulb and C6 glioma cells. We found that gicerin expression was unregulated in the the injured neurons and reactive astrocytes at 7-14 days after the transection of the hypoglossal nerve. It is suggested that gicerin is involved in the network formation of reactive astrocytes and also the neurite outgrowth from the transected nerve end.