Related Experiment Video
Updated: May 19, 2026
08:01
The Soft Agar Colony Formation Assay
Published on: October 27, 2014
Tumour suppressor RNF43 is a stem-cell E3 ligase that induces endocytosis of Wnt receptors
Bon-Kyoung Koo1, Maureen Spit, Ingrid Jordens
1Hubrecht Institute, KNAW and University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands.
Nature
|August 17, 2012
Summary
RNF43 and ZNRF3 E3 ubiquitin ligases control intestinal stem cell growth by regulating Wnt signaling. Deleting these genes in mice causes adenomas dependent on Wnt secreted by Paneth cells.
Area of Science:
- Cell Biology
- Molecular Biology
- Cancer Research
Background:
- LGR5+ stem cells are crucial for intestinal homeostasis and reside near Paneth cells.
- Paneth cells provide essential signals like Wnt, Notch, and EGF to stem cells.
- RNF43 and ZNRF3 are transmembrane E3 ubiquitin ligases with roles in cell signaling.
Purpose of the Study:
- To investigate the role of RNF43 and ZNRF3 in LGR5+ stem cells.
- To determine the impact of RNF43 and ZNRF3 deletion on intestinal adenoma formation.
- To elucidate the mechanism by which RNF43 and ZNRF3 regulate Wnt signaling.
Main Methods:
- Gene deletion studies in mouse intestinal epithelium.
- In vitro organoid culture derived from adenomas.
- HEK293T and HCT116 human cancer cell line experiments.
- Analysis of Wnt signaling pathway components and receptor localization.
Main Results:
- Simultaneous deletion of RNF43 and ZNRF3 in mice induced rapid adenoma growth with increased LGR5+ stem and Paneth cells.
- Adenoma growth was dependent on Wnt secreted by Paneth cells, as shown by organoid culture experiments.
- RNF43 expression blocked Wnt responses in HEK293T cells and targeted frizzled receptors for lysosomal degradation.
- Reintroducing RNF43 into RNF43-mutant colorectal cancer cells abolished their Wnt response.
Conclusions:
- RNF43 and ZNRF3 act as key negative regulators of Wnt signaling in intestinal stem cells.
- These ligases function by ubiquitinating frizzled receptors, leading to their degradation.
- Dysregulation of RNF43/ZNRF3 may contribute to intestinal adenoma and colorectal cancer development.
Related Concept Videos
02:54Canonical Wnt Signaling Pathway
The gene encoding the main signaling molecules of the Wnt signaling pathways (the Wnt proteins) was discovered almost four decades ago by Nüsslein-Volhard and Wieschaus. They identified and originally named the gene "wingless" (wg) after a phenotype discovered during their landmark genetic screen in Drosophila for body pattern defects. At around the same time, another researcher named Harold Varmus found that a murine tumor virus activates the mammalian wg homolog, Int-1, which results in tumor...
01:22Role of Ephrin-Eph Signalling in Intestinal Stem Cell Renewal
Erythropoietin-producing hepatocellular carcinoma receptor (Eph) and its ligand, Eph receptor-interacting protein (Ephrin) were first discovered in the human carcinoma cell line, hence the name. Ephrin-Eph interaction guides cells to reach their appropriate location in adult tissues. They also play an essential role in the immune system by helping in immune cell migration, adhesion, and activation. Based on their structure and function, Eph is divided into two classes — EphA and EphB.
02:23Abnormal Proliferation
Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the daughter...
01:23Negative Regulator Molecules
Positive regulators allow a cell to advance through cell cycle checkpoints. Negative regulators have an equally important role as they terminate a cell’s progression through the cell cycle—or pause it—until the cell meets specific criteria.
01:41Non-Canonical Wnt Signaling Pathways
Wnt is a zygotic effect gene that is expressed during very early embryonic development. It regulates various processes in animals starting from early development through the adult stage, such as organogenesis in the embryo and maintenance of neuronal and blood stem cells. Wnt proteins can induce a wide variety of intracellular pathways depending upon the specific abilities of different Wnt ligands to form a complex with shared and cognate receptors in the presence of different co-receptors. The...
01:12Role Of Notch Signalling In Intestinal Stem Cell Renewal
Notch signaling was first discovered in Drosophila melanogaster, where it is involved in cell lineage differentiation. Notch signaling regulates the maintenance and differentiation of intestinal stem cells or ISCs by controlling the expression of atonal homolog 1 or Atoh1. Atoh1 directs cells to differentiate into secretory cells.
Direct cell-to-cell contact is needed for the activation of Notch signaling. The signal is initiated when a notch ligand binds to a receptor on an adjacent cell, also...
Direct cell-to-cell contact is needed for the activation of Notch signaling. The signal is initiated when a notch ligand binds to a receptor on an adjacent cell, also...