5WZZ

The SIAH E3 ubiquitin ligases promote Wnt/ beta-catenin signaling through mediating Wnt-induced Axin degradation


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.103 Å
  • R-Value Free: 0.208 
  • R-Value Work: 0.184 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

The SIAH E3 ubiquitin ligases promote Wnt/ beta-catenin signaling through mediating Wnt-induced Axin degradation

Ji, L.Jiang, B.Jiang, X.Charlat, O.Chen, A.Mickanin, C.Bauer, A.Xu, W.Yan, X.-X.Cong, F.

(2017) Genes Dev. 31: 904-915

  • DOI: 10.1101/gad.300053.117

  • PubMed Abstract: 
  • The Wnt/β-catenin signaling pathway plays essential roles in embryonic development and adult tissue homeostasis. Axin is a concentration-limiting factor responsible for the formation of the β-catenin destruction complex. Wnt signaling itself promotes ...

    The Wnt/β-catenin signaling pathway plays essential roles in embryonic development and adult tissue homeostasis. Axin is a concentration-limiting factor responsible for the formation of the β-catenin destruction complex. Wnt signaling itself promotes the degradation of Axin. However, the underlying molecular mechanism and biological relevance of this targeting of Axin have not been elucidated. Here, we identify SIAH1/2 (SIAH) as the E3 ligase mediating Wnt-induced Axin degradation. SIAH proteins promote the ubiquitination and proteasomal degradation of Axin through interacting with a VxP motif in the GSK3-binding domain of Axin, and this function of SIAH is counteracted by GSK3 binding to Axin. Structural analysis reveals that the Axin segment responsible for SIAH binding is also involved in GSK3 binding but adopts distinct conformations in Axin/SIAH and Axin/GSK3 complexes. Knockout of SIAH1 blocks Wnt-induced Axin ubiquitination and attenuates Wnt-induced β-catenin stabilization. Our data suggest that Wnt-induced dissociation of the Axin/GSK3 complex allows SIAH to interact with Axin not associated with GSK3 and promote its degradation and that SIAH-mediated Axin degradation represents an important feed-forward mechanism to achieve sustained Wnt/β-catenin signaling.


    Organizational Affiliation

    Chemical Biology and Therapeutics, Novartis Institutes for Biomedical Research, Cambridge, Massachusetts 02139, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
E3 ubiquitin-protein ligase SIAH1
A, B, C, D
190Homo sapiensMutation(s): 0 
Gene Names: SIAH1 (HUMSIAH)
EC: 2.3.2.27
Find proteins for Q8IUQ4 (Homo sapiens)
Go to Gene View: SIAH1
Go to UniProtKB:  Q8IUQ4
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Axin-1
E, F, G, H
20Homo sapiensMutation(s): 0 
Gene Names: AXIN1 (AXIN)
Find proteins for O15169 (Homo sapiens)
Go to Gene View: AXIN1
Go to UniProtKB:  O15169
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download SDF File 
Download CCD File 
A, B, C, D
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.103 Å
  • R-Value Free: 0.208 
  • R-Value Work: 0.184 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 41.502α = 90.00
b = 86.450β = 98.43
c = 117.454γ = 90.00
Software Package:
Software NamePurpose
PHENIXrefinement
HKL-2000data reduction
PHASERphasing
HKL-2000data scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2017-08-16
    Type: Initial release
  • Version 1.1: 2017-08-23
    Type: Structure summary
  • Version 1.2: 2017-08-30
    Type: Data collection