The Wnt Receptor Ryk Plays a Role in Mammalian Planar Cell Polarity Signaling
The Wnt Receptor Ryk Plays a Role in Mammalian Planar Cell Polarity Signaling
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DOI：
10.1074/jbc.m112.362681
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发表时间：
2012-08-24
影响因子：
4.8
通讯作者：
Stacker, Steven A.
中科院分区：
文献类型：
--
作者：
Macheda, Maria L.;Sun, Willy W.;Stacker, Steven A.
wnt对包括细胞生长、分裂和分化在内的一系列发育过程至关重要。其中一些过程通过平面细胞极性（PCP）通路发出信号，这是一种与β -连环蛋白无关的Wnt信号通路。先前的研究表明，Ryk是酪氨酸激酶受体家族的一员，可以与wnt结合。Ryk是发育过程中正常轴突引导和神经元分化所必需的。在这里，我们证明哺乳动物Ryk与Wnt/PCP通路相互作用。体外分析表明Ryk的Wnt抑制因子域是Wnt结合所必需的。两种脊椎动物模型生物的详细分析显示Ryk表型与PCP信号一致。在斑马鱼中，使用morpholinos敲除基因揭示了在PCP途径调控的胚胎趋同扩展过程中Ryk和Wnt11之间的遗传相互作用。ryk缺陷小鼠胚胎在耳蜗中显示出立体纤毛细胞极性的破坏，这是PCP信号紊乱的一个特征。在Ryk和Looptail的双杂合子小鼠胚胎中也观察到这种PCP缺陷（包含Wnt/PCP通路核心基因Vangl2的突变），但在任何一个单杂合子中都没有发现，这表明Ryk和Vangl2之间存在遗传相互作用。共免疫沉淀研究表明，RYK和VANGL2蛋白形成一个复合物，而RYK也激活RhoA，这是PCP信号的下游效应物。总的来说，我们的数据表明Ryk在脊椎动物发育过程中通过Vangl2信号通路参与Wnt/平面细胞极性信号传导的重要作用，正如在小鼠耳蜗中所证明的那样。
Wnts are essential for a wide range of developmental processes, including cell growth, division, and differentiation. Some of these processes signal via the planar cell polarity (PCP) pathway, which is a beta-catenin-independent Wnt signaling pathway. Previous studies have shown that Ryk, a member of the receptor tyrosine kinase family, can bind to Wnts. Ryk is required for normal axon guidance and neuronal differentiation during development. Here, we demonstrate that mammalian Ryk interacts with the Wnt/PCP pathway. In vitro analysis showed that the Wnt inhibitory factor domain of Ryk was necessary for Wnt binding. Detailed analysis of two vertebrate model organisms showed Ryk phenotypes consistent with PCP signaling. In zebrafish, gene knockdown using morpholinos revealed a genetic interaction between Ryk and Wnt11 during the PCP pathway-regulated process of embryo convergent extension. Ryk-deficient mouse embryos displayed disrupted polarity of stereociliary hair cells in the cochlea, a characteristic of disturbed PCP signaling. This PCP defect was also observed in mouse embryos that were double heterozygotes for Ryk and Looptail (containing a mutation in the core Wnt/PCP pathway gene Vangl2) but not in either of the single heterozygotes, suggesting a genetic interaction between Ryk and Vangl2. Co-immunoprecipitation studies demonstrated that RYK and VANGL2 proteins form a complex, whereas RYK also activated RhoA, a downstream effector of PCP signaling. Overall, our data suggest an important role for Ryk in Wnt/planar cell polarity signaling during vertebrate development via the Vangl2 signaling pathway, as demonstrated in the mouse cochlea.