Analysis of the mechanism of neurite outgrowth driven by membrane transport and cytoskeletal reorganization

细胞骨架的重组和膜的添加是神经突生长的关键。在这里，我们研究了使用FRET生物传感器的膜添加的调节机制。TC 10活性在质膜上下降，在延长生长锥。GTP水解TC 10促进神经突生长通过胞外融合Rab 11和L1-含有囊泡通过释放胞外组分Exo 70。我们为Rab 35开发了FRET传感器，Rab 35促进神经突生长。利用Rab 35传感器，我们发现Rab 35在生长锥的质膜上的活性高于神经突轴和细胞体。PKA对STEF的磷酸化对dbcAMP处理的PC 12 D细胞中Rac 1的激活和神经突生长至关重要。我们建议，在神经突尖端的Rac 1和Cdc 42的局部激活是必要的神经突生长。海马神经元中Rap 1B的最长神经突特异性激活有助于通过RalA和Nore 1A以及PI 3-激酶形成极性。

Cytoskeletal reorganization and the membrane addition are pivotal for neurite outgrowth. Here we studied the regulation-mechanism of membrane addition using FRET biosensors. TC10 activity at the plasma membrane decreased at extending growth cones. GTP hydrolysis of TC10 promotes neurite outgrowth through exocytic fusion of Rab11- and L1-containing vesicles by releasing exocyst component Exo70. We developed FRET sensor for Rab35, which promotes neurite outgrowth. Using Rab35 sensor, we showed that Rab35 activity at plasma membrane of growth cones was higher than that of neurite shafts and cell bodies. Phosphorylation of STEF by PKA is critical for Rac1 activation and neurite outgrowth in dbcAMP-treated PC12D cells. We propose that local activation of Rac1 and Cdc42 at neurite tips is necessary for neurite outgrowth. Longest neurite-specific activation of Rap1B in hippocampal neurons contributes to polarity formation through RalA and Nore1A in addition to PI3-kinase.