Building a complex for destruction
| Autor: | Felix van der Krift, Anton J. Venhuizen, Madelon M. Maurice |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
SCFβ-TrCP
beta-catenin destruction complex Core component colorectal cancer Cell Biology Wnt/beta-catenin signalling Biology Article Cell biology law.invention axis inhibition protein (AXIN) casein kinase 1 (CK1) law adenomatous polyposis coli (APC) ubiquitin Suppressor biochemistry Molecular Biology glycogen synthase kinase 3 (GSK3) |
| Zdroj: | Molecular Cell |
| ISSN: | 1097-4164 |
| Popis: | Summary The Wnt/β-catenin pathway is a highly conserved, frequently mutated developmental and cancer pathway. Its output is defined mainly by β-catenin’s phosphorylation- and ubiquitylation-dependent proteasomal degradation, initiated by the multi-protein β-catenin destruction complex. The precise mechanisms underlying destruction complex function have remained unknown, largely because of the lack of suitable in vitro systems. Here we describe the in vitro reconstitution of an active human β-catenin destruction complex from purified components, recapitulating complex assembly, β-catenin modification, and degradation. We reveal that AXIN1 polymerization and APC promote β-catenin capture, phosphorylation, and ubiquitylation. APC facilitates β-catenin’s flux through the complex by limiting ubiquitylation processivity and directly interacts with the SCFβ-TrCP E3 ligase complex in a β-TrCP-dependent manner. Oncogenic APC truncation variants, although part of the complex, are functionally impaired. Nonetheless, even the most severely truncated APC variant promotes β-catenin recruitment. These findings exemplify the power of biochemical reconstitution to interrogate the molecular mechanisms of Wnt/β-catenin signaling. Graphical abstract Highlights • β-Catenin destruction complex function recapitulated with purified proteins • AXIN1 polymers and APC promote β-catenin capture, phosphorylation, and ubiquitylation • Oncogenic APC truncation mutants are hypomorphs promoting β-catenin recruitment • APC directly binds the ubiquitylation machinery Ranes et al. reconstitute the β-catenin destruction complex from purified proteins, thereby recapitulating its assembly and biochemical activities and enabling the mechanistic interrogation of its scaffolding proteins AXIN1 and APC. AXIN1 polymerization and APC facilitate the recruitment, phosphorylation, and ubiquitylation of β-catenin. Oncogenic truncation of APC partially preserves APC function. |
| Databáze: | OpenAIRE |
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