Lin C H, Espreafico E M, Mooseker M S, Forscher P
National Yang-Ming University, Taipei, Taiwan.
Neuron. 1996 Apr;16(4):769-82. doi: 10.1016/s0896-6273(00)80097-5.
Actin filaments assembled at the leading edge of neuronal growth cones are centripetally transported via retrograde F-actin flow, a process fundamental to growth cone guidance and other forms of directed cell motility. Here we investigated the role of myosins in retrograde flow, using two distinct modes of myosin inhibition: microinjection of NEM inactivated myosin S1 fragments, or treatment with 2,3-butanedione-2-monoxime, and inhibitor of myosin ATPase. Both treatments resulted in dose-dependent attenuation of retrograde F-actin flow and growth of filopodia. Growth was cytochalasin sensitive and directly proportional to the degree of myosin inhibition, suggesting that retrograde flow results from superimposition of two independent processes: actin assembly and myosin-based filament retraction. These results provide the first direct evidence for myosin involvement in neuronal growth cone function.
在神经元生长锥前缘组装的肌动蛋白丝通过逆向F-肌动蛋白流进行向心运输，这是生长锥导向和其他形式的定向细胞运动的一个基本过程。在这里，我们使用两种不同的肌球蛋白抑制模式研究了肌球蛋白在逆向流中的作用：显微注射NEM使肌球蛋白S1片段失活，或用2,3-丁二酮-2-单肟（一种肌球蛋白ATP酶抑制剂）处理。两种处理均导致逆向F-肌动蛋白流和丝状伪足生长的剂量依赖性减弱。生长对细胞松弛素敏感，且与肌球蛋白抑制程度成正比，这表明逆向流是由两个独立过程叠加产生的：肌动蛋白组装和基于肌球蛋白的丝回缩。这些结果为肌球蛋白参与神经元生长锥功能提供了首个直接证据。
