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Updated: Jul 2, 2026

Functional Characterization of RING-Type E3 Ubiquitin Ligases In Vitro and In Planta

Functional Characterization of RING-Type E3 Ubiquitin Ligases In Vitro and In Planta

Published on: December 5, 2019

ZNRF3 and RNF43 are active monomeric E3 ubiquitin ligases that self-associate.

Prasanth Padala¹, Claudia Rossig¹, Jennifer M Crowther²

¹Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin 9054, New Zealand.

Science Signaling

|June 30, 2026

Summary

RNF43 and ZNRF3 are RING E3 ubiquitin ligases that regulate WNT signaling by targeting Frizzled (FZD) receptors. Their inactivation leads to cancer, and this study elucidates the structural and functional mechanisms of their ubiquitin ligase activity.

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Last Updated: Jul 2, 2026

Functional Characterization of RING-Type E3 Ubiquitin Ligases In Vitro and In Planta

Functional Characterization of RING-Type E3 Ubiquitin Ligases In Vitro and In Planta

Published on: December 5, 2019

In Vitro Analysis of E3 Ubiquitin Ligase Function

In Vitro Analysis of E3 Ubiquitin Ligase Function

Published on: May 14, 2021

Detection of Protein Ubiquitination

Detection of Protein Ubiquitination

Published on: August 19, 2009

Area of Science:

Molecular Biology
Cell Biology
Biochemistry

Background:

WNT signaling pathway controls cell proliferation and stem cell maintenance.
Aberrant WNT signaling activation leads to excessive cell division and cancer.
RING E3 ubiquitin ligases RNF43 and ZNRF3 inactivate WNT signaling by targeting Frizzled (FZD) receptors for degradation.

Purpose of the Study:

To identify the determinants of ubiquitin transfer by ZNRF3 and RNF43.
To determine the structure of the ZNRF3 RING domain.
To elucidate the regulatory mechanisms of ZNRF3 and RNF43 E3 ubiquitin ligase activity.

Main Methods:

Structural analysis of the ZNRF3 RING domain.
Biochemical assays to assess ubiquitin ligase activity.
Cellular proximity studies to investigate domain interactions.

Main Results:

The ZNRF3 RING domain is monomeric and does not require dimerization for ubiquitin ligase activity.
The ectodomain of ZNRF3 dimerizes, suggesting a model where cytoplasmic domains interact.
RING dimerization is not essential for ubiquitin transfer by ZNRF3 and RNF43.

Conclusions:

This study provides a structural and functional framework for understanding RNF43 and ZNRF3 E3 ubiquitin ligase regulation.
The findings offer insights into how these ligases control WNT signaling.
Understanding these mechanisms is crucial for cancer research and therapeutic development.