在神经元极化过程中,LKB1/STRAD促进了轴突启动
Maya Shelly1, Laura Cancedda, Sarah Heilshorn
1Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720, USA.
Cell
|May 8, 2007
概括
局部积累的LKB1和STRAD蛋白质在发育中的神经元中信号轴突启动. 这一过程需要依赖蛋白质激酶A (PKA) 的LKB1酸化,以实现适当的轴突分化.
科学领域:
- 神经科学是一个神经科学.
- 细胞生物学 细胞生物学
- 发展生物学 发展生物学
背景情况:
- 轴突和树突的分化是神经元发育的基本过程.
- 建立神经元极性对于正确的神经系统功能至关重要.
- LKB1和STRAD在神经元极性和轴突形成中的作用尚未完全理解.
研究的目的:
- 研究LKB1和STRAD蛋白在神经元发育中的轴突分化的作用.
- 确定LKB1和STRAD调节轴突形成的分子机制.
- 为了确定参与早期轴突启动的信号通路.
主要方法:
- 利用培养的海马神经元和发育中的皮质神经元 in vivo.
- 使用siRNA介导的LKB1和STRAD的淘汰和过度表达.
- 研究了LKB1酸化在血清431 (S431) 的作用,使用局部定向突变发生 (LKB1(S431A)).
- 评估了PKA激活剂 (BDNF, dibutyryl-cAMP) 对轴突分化的影响.
主要成果:
- 在未分化的神经元中LKB1和STRAD的积累与随后的轴突分化相关.
- 低调 LKB1 或 STRAD 抑制了轴突形成,而过度表达导致了多个轴突.
- 与LKB1的STRAD相互作用促进了S431的LKB1酸化,并增加了LKB1水平.
- 过度表达一种非化LKB1突变体 (LKB1(S431A)) 阻断了轴突分化在体外和体内.
- PKA-依赖的LKB1酸化对于BDNF或dibutyryl-cAMP诱导的轴突分化至关重要.
结论:
- 当地LKB1和STRAD的积累作为轴突启动的早期信号.
- 在S431的LKB1的PKA依赖酸化是轴突分化的关键步骤.
- 这些发现阐明了调节神经元极性和轴突形成的关键分子机制.
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