Weidinger Gilbert, Moon Randall T
Howard Hughes Medical Institute and Department of Pharmacology, University of Washington, Box 357370, Seattle, WA 98195, USA.
J Cell Biol. 2003 Sep 1;162(5):753-5. doi: 10.1083/jcb.200307181.
Secreted Wnt ligands appear to activate a variety of signaling pathways. Two papers in this issue now present genetic evidence that "noncanonical" Wnt signaling inhibits the "canonical" Wnt/beta-catenin pathway. Westfall et al. (2003a) show that zebrafish embryos lacking maternal Wnt-5 function are dorsalized due to ectopic activation of beta-catenin, whereas Topol et al. (2003) report that chondrogenesis in the distal mouse limb bud depends on inhibition of Wnt/beta-catenin signaling by a paralogue of Wnt-5. These studies present the first genetic confirmation of the previous hypothesis that vertebrate Wnt signaling pathways can act in an antagonistic manner.
分泌型Wnt配体似乎能激活多种信号通路。本期的两篇论文提供了遗传学证据，表明“非经典”Wnt信号传导会抑制“经典”Wnt/β-连环蛋白信号通路。韦斯特福尔等人（2003年a）表明，缺乏母体Wnt-5功能的斑马鱼胚胎会因β-连环蛋白的异位激活而背化，而托波尔等人（2003年）报告称，小鼠远端肢体芽中的软骨形成取决于Wnt-5的一个旁系同源物对Wnt/β-连环蛋白信号传导的抑制作用。这些研究首次对之前的假说进行了遗传学证实，即脊椎动物的Wnt信号通路可以以拮抗方式发挥作用。
