Ledda Fernanda
Laboratory of Molecular and Cellular Neuroscience, Department of Neuroscience, Karolinska Institute, Stockholm 171 77, Sweden.
Cell Adh Migr. 2007 Jul-Sep;1(3):137-9. doi: 10.4161/cam.1.3.4985. Epub 2007 Jul 5.
The formation of neuronal synapses is a finely organized process that involves the presynaptic assembly of the machinery responsible for neurotransmitter release and the postsynaptic recruitment of neurotransmitter receptors and scaffold proteins to the postsynaptic density (PSD). The molecular cues guiding the establishment of synaptic connections are now beginning to be identified. Recent studies indicate that cell adhesion molecules (CAMs) participate prominently in the key steps of synapse formation, inducing transsynaptic adhesion and promoting a precise alignment of pre- and postsynaptic terminals. This addendum describes a new mechanism of cell-cell interaction that combines features of both diffusible and membrane-bound synaptogenic factors. It particularly points out the key role played by GDNF triggering trans-homophilic binding between GFR alpha 1 molecules and cell adhesion between GFR alpha 1-expressing cells. In this model GFR alpha 1 functions as a ligand-induced cell adhesion molecule (LICAM) to establish precise synaptic contacts and promote the assembly of presynaptic terminals. In this overview, I summarize the current concepts of synapse formation in the limelight of this new mechanism of ligand-induced cell adhesion.
神经元突触的形成是一个精细组织的过程，它涉及负责神经递质释放的 machinery 的突触前组装以及神经递质受体和支架蛋白向突触后致密区（PSD）的突触后募集。现在开始识别指导突触连接建立的分子线索。最近的研究表明，细胞粘附分子（CAMs）在突触形成的关键步骤中起着重要作用，诱导跨突触粘附并促进突触前和突触后末端的精确对齐。本附录描述了一种新的细胞间相互作用机制，该机制结合了可扩散和膜结合的突触发生因子的特征。它特别指出了 GDNF 在触发 GFRα1 分子之间的反式同源结合以及表达 GFRα1 的细胞之间的细胞粘附方面所起的关键作用。在这个模型中，GFRα1 作为配体诱导的细胞粘附分子（LICAM）发挥作用，以建立精确的突触接触并促进突触前末端的组装。在本综述中，我根据这种新的配体诱导细胞粘附机制总结了当前突触形成的概念。
