Reconstitution of the destruction complex defines roles of AXIN polymers and APC in β-catenin capture, phosphorylation, and ubiquitylation.
Date
2021-08-19Author
Ranes, M
Zaleska, M
Sakalas, S
Knight, R
Guettler, S
Type
Journal Article
Metadata
Show full item recordAbstract
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.
Collections
Subject
SCF(β-TrCP)
Wnt/beta-catenin signalling
adenomatous polyposis coli (APC)
axis inhibition protein (AXIN)
beta-catenin destruction complex
biochemistry
casein kinase 1 (CK1)
colorectal cancer
glycogen synthase kinase 3 (GSK3)
ubiquitin
Adenomatous Polyposis Coli Protein
Axin Protein
Humans
Multiprotein Complexes
Phosphorylation
Protein Multimerization
Proteolysis
Ubiquitination
Wnt Signaling Pathway
beta Catenin
Research team
Struct Biol Cell Signal
Language
eng
Date accepted
2021-07-13
License start date
2021-08-19
Citation
Molecular Cell, 2021, 81 (16), pp. 3246 - 3261.e11
Publisher
CELL PRESS