Campagna J A, Rüegg M A, Bixby J L
Department of Molecular and Cellular Pharmacology, R-189, University of Miami School of Medicine, Florida 33136, USA.
Neuron. 1995 Dec;15(6):1365-74. doi: 10.1016/0896-6273(95)90014-4.
Proteins of the synaptic basal lamina are important in directing the differentiation of motor nerve terminals. One synaptic basal lamina protein, agrin, which influences postsynaptic muscle differentiation, has been suggested to influence nerve terminals as well. To test this hypothesis, we cocultured chick ciliary ganglion neurons with agrin-expressing CHO cells. Ciliary ganglion neurons, but not sensory neurons, adhered five times as well to agrin-expressing cells as to untransfected cells. Further, ciliary ganglion neurites were growth inhibited upon contact with agrin-expressing cells. Finally, the synaptic vesicle protein synaptotagmin became concentrated at contacts between ciliary ganglion neurites and agrin-expressing cells. These activities were shared by neuronal and muscle-derived agrin isoforms, consistent with the hypothesis that muscle agrin may influence the presynaptic axon. Our results suggest that agrin influences the growth and differentiation of motoneurons in vivo.
突触基底层的蛋白质在指导运动神经末梢的分化中起重要作用。一种影响突触后肌肉分化的突触基底层蛋白质——聚集蛋白，也被认为会影响神经末梢。为了验证这一假设，我们将鸡睫状神经节神经元与表达聚集蛋白的CHO细胞进行了共培养。睫状神经节神经元，而非感觉神经元，与表达聚集蛋白的细胞的黏附能力是未转染细胞的五倍。此外，睫状神经节神经突在与表达聚集蛋白的细胞接触时生长受到抑制。最后，突触囊泡蛋白突触结合蛋白在睫状神经节神经突与表达聚集蛋白的细胞之间的接触处聚集。神经元和肌肉来源的聚集蛋白同工型都具有这些活性，这与肌肉聚集蛋白可能影响突触前轴突的假设一致。我们的结果表明，聚集蛋白在体内会影响运动神经元的生长和分化。
