Essential role of neural Wiskott-Aldrich syndrome protein in neurite extension in PC12 cells and rat hippocampal primary culture cells
Essential role of neural Wiskott-Aldrich syndrome protein in neurite extension in PC12 cells and rat hippocampal primary culture cells
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DOI：
10.1074/jbc.275.16.11987
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发表时间：
2000-04-21
影响因子：
4.8
通讯作者：
Takenawa, T
中科院分区：
文献类型：
--
作者：
Banzai, Y;Miki, H;Takenawa, T
神经Wiskott-Aldrich综合征蛋白（Neural Wiskott-Aldrich syndrome protein，N-WASP）是一种肌动蛋白调节蛋白，其诱导Cdc 42下游的丝状伪足形成。在这里，我们研究了可能参与的N-WASP在神经突起的延伸过程。由于已知N-WASP的verprolin、cofilin同源性和酸性区域（VCA）是诱导肌动蛋白聚合的Arp 2/3复合物的活化所需的，因此我们制备了在cofilin同源性区域中缺少四个氨基酸残基的突变体（Delta cof）。据报道，WASP中的相应残基在一些Wiskott-Aldrich综合征患者中发生突变。Delta cof N-WASP的表达抑制了PC 12细胞的突起延伸。为了支持这一点，与野生型VCA相比，Delta cof的VCA区域不能充分激活Arp 2/3复合物。此外，H208 D突变体，这已被证明不能结合Cdc 42，也作为一个显性负突变体在轴突延伸测定。有趣的是，H208 D-Delta cof双突变体的表达没有显著的显性负效应。最后，Delta cof突变体的表达也严重抑制了大鼠海马原代神经元的轴突延伸。因此，N-WASP被认为是轴突延伸所必需的肌动蛋白细胞骨架的一般调节剂，这可能是通过Cdc 42信号传导和Arp 2/3复合物诱导的肌动蛋白聚合引起的。
Neural Wiskott-Aldrich syndrome protein (N-WASP) is an actin-regulating protein that induces filopodium formation downstream of Cdc42, It has been shown that filopodia actively extend from the growth cone, a guidance apparatus located at the tip of neurites, suggesting their role in neurite extension. Here we examined the possible involvement of N-WASP in the neurite extension process. Since verprolin, cofilin homology and acidic region (VCA) of N-WASP is known to be required for the activation of Arp2/3 complex that induces actin polymerization, we prepared a mutant (Delta cof) lacking four amino acid residues in the cofilin homology region. The corresponding residues in WASP had been reported to be mutated in some Wiskott-Aldrich syndrome patients. Expression of Delta cof N-WASP suppressed neurite extension of PC12 cells. In support of this, the VCA region of Delta cof cannot activate Arp2/3 complex enough compared with wild-type VCA. Furthermore, H208D mutant, which has been shown unable to bind to Cdc42, also works as a dominant negative mutant in neurite extension assay. Interestingly, the expression of H208D-Delta cof double mutant has no significant dominant negative effect. Finally, the expression of the Delta cof mutant also severely inhibited the neurite extension of primary neurons from rat hippocampus, Thus, N-WASP is thought to be a general regulator of the actin cytoskeleton indispensable for neurite extension, which is probably caused through Cdc42 signaling and Arp2/3 complex-induced actin polymerization.