Department of Pathology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Japan.
Nat Commun. 2012 May 29;3:859. doi: 10.1038/ncomms1861.
Dishevelled is the common mediator of canonical and non-canonical Wnt signalling pathways, which are important for embryonic development, tissue maintenance and cancer progression. In the non-canonical Wnt signalling pathway, the Rho family of small GTPases acting downstream of Dishevelled has essential roles in cell migration. The mechanisms by which the non-canonical Wnt signalling pathway regulates Rac activation remain unknown. Here we show that Daple (Dishevelled-associating protein with a high frequency of leucine residues) regulates Wnt5a-mediated activation of Rac and formation of lamellipodia through interaction with Dishevelled. Daple increases the association of Dishevelled with an isoform of atypical protein kinase C, consequently promoting Rac activation. Accordingly, Daple deficiency impairs migration of fibroblasts and epithelial cells during wound healing in vivo. These findings indicate that Daple interacts with Dishevelled to direct the Dishevelled/protein kinase λ protein complex to activate Rac, which in turn mediates the non-canonical Wnt signalling pathway required for cell migration.
蓬乱蛋白是经典和非经典 Wnt 信号通路的常见介质,这些信号通路对胚胎发育、组织维持和癌症进展很重要。在非经典 Wnt 信号通路中,蓬乱蛋白下游的 Rho 家族小 GTPase 在细胞迁移中起着重要作用。非经典 Wnt 信号通路调节 Rac 激活的机制尚不清楚。本文展示了 Daple(富含亮氨酸残基的蓬乱蛋白相关蛋白)通过与蓬乱蛋白相互作用,调节 Wnt5a 介导的 Rac 激活和片状伪足的形成。Daple 增加了蓬乱蛋白与一种非典型蛋白激酶 C 同工型的结合,从而促进 Rac 的激活。因此,Daple 缺失会损害体内伤口愈合过程中成纤维细胞和上皮细胞的迁移。这些发现表明,Daple 与蓬乱蛋白相互作用,将蓬乱蛋白/蛋白激酶 λ 蛋白复合物引导至激活 Rac,Rac 反过来介导细胞迁移所需的非经典 Wnt 信号通路。