Distinct β-catenins mediate adhesion and signalling functions in C-elegans
Distinct β-catenins mediate adhesion and signalling functions in C-elegans
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DOI：
10.1038/35020099
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发表时间：
2000-08-03
期刊：
影响因子：
64.8
通讯作者：
Clevers, HC
中科院分区：
文献类型：
--
作者：
Korswagen, HC;Herman, MA;Clevers, HC
在果蝇和脊椎动物中，Armadillo/β-catenin与Tcf/Lef-1转录因子形成复合物，作为介导Wnt信号传导的必需共激活因子。它还与钙粘蛋白结合以介导粘附。在秀丽隐杆线虫中，已经鉴定了三种推定的β-连环蛋白同源物：WRM-1、BAR-1和HMP-2。WRM-1和Tcf同源物POP-1通过挑战Wnt途径的当前观点的机制介导Wnt信号传导（1-3）。在这里，我们表明，BAR-1是唯一的β-连环蛋白同系物，直接与POP-1相互作用。BAR-1通过形成BAR-1/POP-1双链转录因子介导Wnt信号传导，所述双链转录因子激活Wnt靶基因如Hox基因mAb-5的表达。HMP-2是唯一一个与C. elegans，HMR-1.我们的结论是，一个典型的Wnt途径存在于C。优雅的。此外，我们的分析表明，C。在粘附和信号传导中，秀丽线虫β-连环蛋白由不同的蛋白质执行。
In flies and vertebrates, Armadillo/beta-catenin forms a complex with Tcf/Lef-1 transcription factors, serving as an essential coactivator to mediate Wnt signalling. It also associates with cadherins to mediate adhesion. In Caenorhabditis elegans, three putative beta-catenin homologues have been identified: WRM-1, BAR-1 and HMP-2. WRM-1 and the Tcf homologue POP-1 mediate Wnt signalling by a mechanism that has challenged current views of the Wnt pathway(1-3). Here we show that BAR-1 is the only beta-catenin homologue that interacts directly with POP-1. BAR-1 mediates Wnt signalling by forming a BAR-1/POP-1 bipartite transcription factor that activates expression of Wnt target genes such as the Hox gene mab-5. HMP-2 is the only beta-catenin homologue that interacts with the single cadherin of C. elegans, HMR-1. We conclude that a canonical Wnt pathway exists in C. elegans. Furthermore, our analysis shows that the functions of C. elegans beta-catenins in adhesion and in signalling are performed by separate proteins.