Doublecortin (Dcx) family proteins regulate filamentous actin structure in developing neurons.
Doublecortin (Dcx) family proteins regulate filamentous actin structure in developing neurons.
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DOI：
10.1523/jneurosci.4603-12.2013
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发表时间：
2013-01-09
期刊：
影响因子：
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通讯作者：
Liu JS
中科院分区：
文献类型：
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作者：
Fu X;Brown KJ;Yap CC;Winckler B;Jaiswal JK;Liu JS
双皮质素（Dcx）是X连锁无脑畸形的致病基因，其编码微管（MT）结合蛋白。轴突束在受影响的个体和动物模型中都异常。为了确定轴突束缺陷的原因，我们对Dcx突变小鼠的胼胝体进行了半定量蛋白质组学分析。与野生型轴突相比，在Dcx突变小鼠的轴突中，肌动蛋白相关蛋白存在广泛的差异。肌动蛋白结合蛋白，α-actinin-1，α-actinin-4和肌动蛋白相关蛋白2/3复合亚基3（Arp 3）的减少与突变神经元中丝状肌动蛋白（F-actin）分布的失调有关，细胞体周围的F-actin增加，神经突和生长锥中的F-actin减少。肌动蛋白分布缺陷可以被全长Dcx挽救，并且被Dcx S297 A（不可磷酸化的突变体）进一步增强，但不能被缺失C末端S/P丰富结构域的Dcx的截短突变体所增强。因此，Dcx的C-末端区域动态调节发育神经元中F-肌动蛋白特征的形成，可能是通过与亲棘素相互作用，而不是通过α-辅肌动蛋白-4或Arp 3。我们发现Dcx/双皮质素样激酶1（Dclk 1）缺陷的表型与肌动蛋白缺陷一致，因为这些轴突选择性缺乏轴突导向，而不是伸长。
Doublecortin (Dcx) is the causative gene for X-linked lissencephaly, which encodes a microtubule (MT) binding protein. Axon tracts are abnormal in both affected individuals and in animal models. To determine the reason for the axon tract defect, we performed a semi-quantitative proteomic analysis of the corpus callosum in mice mutant for Dcx. In axons from mice mutant for Dcx, wide spread differences are found in actin-associated proteins as compared with wild type axons. Decreases in actin-binding proteins, α-actinin-1, α-actinin-4 and actin-related protein 2/3 complex subunit 3 (Arp3), are correlated with dysregulation in the distribution of filamentous actin (F-actin) in the mutant neurons with increased F-actin around the cell body and decreased F-actin in the neurites and growth cones. The actin distribution defect can be rescued, by full length Dcx, and further enhanced by Dcx S297A, the unphosphorylatable mutant, but not with the truncation mutant of Dcx missing the C terminal S/P rich domain. Thus, the C-terminal region of Dcx dynamically regulates formation of F-actin features in developing neurons, likely through interaction with spinophilin, but not through α-actinin-4 or Arp3. We show with that the phenotype of Dcx/Doublecortin Like Kinase 1 (Dclk1) deficiency is consistent with actin defect as these axons are selectively deficient in axon guidance, but not elongation.