THE KLHL12-CULLIN-3 UBIQUITIN LIGASE NEGATIVELY REGULATES THE WNT-BETA-CATENIN

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。杂乱是一种保守的蛋白质，它解释Frizzleed受体接收到的信号。使用串联亲和纯化策略和质谱分析，我们已经鉴定了与蓬头垢面相关的蛋白质，包括包含BRoad Complex、TramTrack和Brica Brac(BTB)蛋白Kelch-like 12(KLHL12)的cullin-3泛素连接酶复合体。这种E3泛素连接酶复合体被招募来以Wnt依赖的方式凌乱，促进其多泛素化和降解。功能分析表明，在培养细胞中，这种泛素连接酶对杂乱的调节可以拮抗Wnt-β-catenin途径，在非洲爪哇和斑马鱼胚胎中也是如此。考虑到不同的基于cullin-1的SCF(β-TrCP)复合体调节β-连环蛋白稳定性的证据，我们关于Disheveled稳定性的数据表明，两个不同的泛素连接酶复合体调节Wnt-β-连环蛋白途径。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Dishevelled is a conserved protein that interprets signals received by Frizzled receptors. Using a tandem-affinity purification strategy and mass spectrometry we have identified proteins associated with Dishevelled, including a Cullin-3 ubiquitin ligase complex containing the Broad Complex, Tramtrack and Bric a Brac (BTB) protein Kelch-like 12 (KLHL12). This E3 ubiquitin ligase complex is recruited to Dishevelled in a Wnt-dependent manner that promotes its poly-ubiquitination and degradation. Functional analyses demonstrate that regulation of Dishevelled by this ubiquitin ligase antagonizes the Wnt-beta-catenin pathway in cultured cells, as well as in Xenopus and zebrafish embryos. Considered with evidence that the distinct Cullin-1 based SCF(beta-TrCP)complex regulates beta-catenin stability, our data on the stability of Dishevelled demonstrates that two distinct ubiquitin ligase complexes regulate the Wnt-beta-catenin pathway.