Cell Biology, Istituto Superiore di Sanità, V. le Regina Elena 299, 00161, Rome, Italy.
Cytotechnology. 1991 Feb;5(Suppl 1):162-5. doi: 10.1007/BF00736838.
We have utilized primary cultures from rat cerebellum, 95% enriched in granule cells, to investigate the expression of proteins of the cortical cytoskeleton and of the synaptic vesicles and the relationship between excitatory amino acid receptors activation and calcium dependent proteolysis of fodrin. Exposure of neuronal cell cultures to N-methyl-D-aspartate (NMDA) in the absence of Mg(2+) and in the presence of glycine causes the appearance of 150 kDa proteolytic fragment (s) of-fodrin as detected by immunoblots. The effect of NMDA on fodrin proteolysis is inhibited by the NMDA antagonist 2-amino-5-phosphonovalerate (APV), by 3 mM Mg(2+), by calpain I inhibitor and by the omission of extracellular calcium. The kainate, at the same concentration of NMDA, is less effective and no degradation of fodrin is observed after exposure of cerebellar neurons to quisqualate. These findings suggest that calcium/calpain I-dependent fodrin proteolysis is selectively associated to the functional activation of NMDA receptors.
我们利用大鼠小脑的原代培养物，其中 95%富含颗粒细胞，研究皮质细胞骨架蛋白、突触小泡蛋白的表达以及兴奋性氨基酸受体激活与钙依赖性 fodrin 蛋白水解之间的关系。神经元细胞培养物在无镁和甘氨酸存在的情况下暴露于 N-甲基-D-天冬氨酸 (NMDA) 会导致 fodrin 的 150 kDa 蛋白水解片段 (s) 出现，这可通过免疫印迹检测到。NMDA 对 fodrin 蛋白水解的作用被 NMDA 拮抗剂 2-氨基-5-膦戊酸 (APV)、3 mM Mg(2+)、钙蛋白酶 I 抑制剂以及细胞外钙的缺失所抑制。在相同浓度的 NMDA 下， kainate 的作用较弱，小脑神经元暴露于 quisqualate 后不会观察到 fodrin 的降解。这些发现表明，钙/钙蛋白酶 I 依赖性 fodrin 蛋白水解与 NMDA 受体的功能激活选择性相关。
