Lrrk2缺失损害内质网蛋白输出的机制研究

The study of mechanism of impaired endoplasmic reticulum export induced by Lrrk2 deficiency

目的 探讨帕金森病相关蛋白Lrrk2对内质网蛋白输出功能的调节作用及相关机制。方法 利用Lrrk2基因敲除小鼠(Lrrk2^-/-小鼠)及野生型小鼠(Lrrk2^+/+小鼠)获取成纤维细胞和皮质神经元,应用免疫荧光染色法检测Lrrk2缺失对内质网出口位点(ERES)形态以及对N-甲基-D-天冬氨酸受体(N-methyl-D-asparticacidreceptor,NMDAR)亚基NR2A输出至胞膜的过程的影响。结果 Lrrk2缺失导致成纤维细胞中ERES直径增大,与内质网至高尔基体蛋白运输抑制剂BrefeldinA(BFA)处理效果类似;Lrrk2缺失抑制了河豚毒素(TTX)所诱导的NR2A蛋白输出至胞膜过程。结论 Lrrk2缺失导致内质网至高尔基体蛋白输出功能障碍,而这种异常会抑制神经元活性依赖的NMDA受体蛋白输出至胞膜的过程。

Objective To investigate the regulation of Lrrk2 on endoplasmic reticulum export and the related mechanism. Methods Immunostaining was applied on fibroblasts and cortical neurons derived from Lrrk2 knockout mice( Lrrk2^-/-mice) and wild type mice( Lrrk2^+/+ mice) to detect the effects of Lrrk2 deficiency on the morphology of endoplasmic reticulum exit sites( ERES) and the delivery of NMDAR( N-methyl-D-aspartic acid receptor) subunit NR2A to the cell membrane in . Results The knockout of Lrrk2 increased the diameter of ERES in fibroblasts, similar to the effect of BFA, an inhibitor of ER to Golgi export. Lrrk2 deletion inhibited the protein export of NR2A to cell membrane induced by TTX treatment. Conclusion Loss of Lrrk2 impaired ER to Golgi export,thereby inhibits the activity-dependent NMDA receptor protein export to cell membrane.