Analysis of the information network for protein synthesis and metabolism in neuron

本项目以果蝇光感受器细胞作为神经元的模型细胞，研究了囊泡运输的网络系统及其基本步骤之间的通信，重点研究了Rab蛋白。为此，我研究了Rab蛋白在组织和细胞内的分布，并对这些Rab蛋白的显性阴性突变体的表型进行了生化和形态学分析。研究结果如下：1。位于感光膜区域和轴突区域的蛋白质在RAB1.2的控制下从内质网转运到高尔基体。RAB2可能控制从高尔基体到光接受膜、轴突膜和溶酶体的所有通路。这表明RAB2可能在这些途径之间连接。RAB11特异性控制反式高尔基网络和光感受膜之间的囊泡运输。此外，由于该突变体的光感受器细胞的形态表型与被光异常激活的光感受器细胞的形态表型非常相似，因此PAB11可能通知了光感受器膜的状况。光感受器膜区域内吞作用的早期阶段由RAB5控制。相反，突触囊泡的循环，轴突区域的一个主要内吞系统，是独立于RAB5的。这表明轴突区域在光感受器细胞中形成了部分自持系统。

In this project, the network system of vesicle transport and the communication between its elementary steps have been studied with special attention to Rab proteins by using Drosophila photoreceptor cell as a model cell for neuron. For this purpose, I investigated the tissue- and intracellular-distribution of Rab proteins, and carried out the biochemical and morphological analyses of the phenotypes of the dominant negative mutants of these Rab proteins. The results are as follows :1. Proteins localized in the photoreceptive membrane domain as well as those in the axonal domain are transported from the rER to the Golgi body under the control of RAB1.2. RAB2 would possibly control all pathways from the Golgi body to the photo-receptive membrane, the axonal membrane and the lysosome. This suggests that RAB2 would links between these pathways.3. RAB11 specifically controls the vesicle transport between the trans-Golgi network and the photoreceptive membrane. Moreover, PAB11 may possibly inform the condition of the photoreceptive membrane because the morphological phenotype of photoreceptor cells in this mutant closely resembles to that of the photoreceptor cells abnormally activated by light.4. The early step of endocytosis in the photoreceptor membrane region is controlled by RAB5. In contrast, the recycling of the synaptic vesicles, a major endocytic system in the axonal region, is independent of RAB5. This suggests that the axonal region would develop the partly self-supported system in the photoreceptor cell.