Related Experiment Video

Updated: Sep 16, 2026

Reconstitution Of β-catenin Degradation In Xenopus Egg Extract
09:41

Reconstitution Of β-catenin Degradation In Xenopus Egg Extract

Published on: June 18, 2014

Wnt signaling to beta-catenin involves two interactive components. Glycogen synthase kinase-3beta inhibition and

R H Chen1, W V Ding, F McCormick

  • 1University of California, San Francisco, School of Medicine, Cancer Research Institute, San Francisco, California 94115, USA.

The Journal of Biological Chemistry
|April 6, 2000
PubMed

Insights

Lithium mimics Wnt signaling by inhibiting GSK-3beta, leading to beta-catenin accumulation. Growth factors enhance this effect via protein kinase C (PKC) activation, suggesting a two-component Wnt pathway.

Area of Science:

  • Cellular biology
  • Molecular signaling pathways

Background:

  • Wnt signaling is crucial for embryonic development and cancer.
  • Glycogen synthase kinase-3beta (GSK-3beta) inhibition and beta-catenin elevation characterize Wnt signaling.
  • Lithium is known to mimic Wnt signaling by inactivating GSK-3beta.

Purpose of the Study:

  • To investigate how serum and growth factors modulate lithium-induced beta-catenin accumulation.
  • To elucidate the role of protein kinase C (PKC) in Wnt signaling and beta-catenin regulation.
  • To understand the interaction between GSK-3beta inhibition and PKC in Wnt pathway activation.

Main Methods:

  • Utilized 293 and C57MG cell lines.
  • Administered lithium, serum, and growth factors to cells.
  • Employed PKC inhibitors (calphostin C) and dominant-negative PKC.
  • Assessed cytoplasmic beta-catenin accumulation and Wnt-mediated transcriptional activation.

Main Results:

  • Serum enhances lithium-induced beta-catenin accumulation, mediated by growth factors.
  • Growth factors activate protein kinase C (PKC) to enhance beta-catenin accumulation.
  • PKC activation, not Ras or phosphatidylinositol 3-kinase, is responsible for this enhancement.
  • PKC inhibition partially reduces Wnt-induced beta-catenin accumulation and transcriptional activity.

Conclusions:

  • Wnt signaling to beta-catenin involves two interactive components: GSK-3beta inhibition (mimicked by lithium) and PKC activation.
  • PKC augments the effects of GSK-3beta inhibition in the Wnt pathway.
  • This suggests a complex regulatory mechanism for beta-catenin stabilization and Wnt pathway activation.

More Related Videos

The Soft Agar Colony Formation Assay08:01

The Soft Agar Colony Formation Assay

Published on: October 27, 2014

Studying TGF-β Signaling and TGF-β-induced Epithelial-to-mesenchymal Transition in Breast Cancer and Normal Cells06:54

Studying TGF-β Signaling and TGF-β-induced Epithelial-to-mesenchymal Transition in Breast Cancer and Normal Cells

Published on: October 27, 2020

Related Concept Videos

Canonical Wnt Signaling Pathway02:54

Canonical 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...
Non-Canonical Wnt Signaling Pathways01:41

Non-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...
Amplifying Signals via Enzymatic Cascade01:22

Amplifying Signals via Enzymatic Cascade

When a ligand binds to a cell-surface receptor, the receptor's intracellular domain changes shape, which may either activate its enzyme function or allow its binding to other molecules. The initial signal is amplified by most signal transduction pathways. This means that a single ligand molecule can activate multiple molecules of a downstream target. Proteins that relay a signal are most commonly phosphorylated at one or more sites, activating or inactivating the protein. Kinases catalyze the...
cAMP-dependent Protein Kinase Pathways01:25

cAMP-dependent Protein Kinase Pathways

Cyclic Adenosine Monophosphate (cAMP) is an essential second messenger that activates protein kinase A (PKA) and regulates various biological processes. A single epinephrine molecule binds to GPCR and activates several heterotrimeric G proteins, each stimulating multiple adenylyl cyclase, amplifying the signal, and synthesizing large numbers of cAMP molecules. Small changes in cAMP concentration affect PKA activity. The binding of four cAMP molecules induces a conformational change in PKA,...
Non-Canonical Wnt Signaling Pathways01:41

Non-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...
Catenins01:23

Catenins

Catenins are characterized by multiple binding domains and dynamic structures that allow them to function as linker proteins in cell junction complexes. All catenins, except α-catenin, contain a characteristic protein sequence called the armadillo repeat and are therefore also called armadillo proteins.
Catenins in Cell Junctions
Catenins bind to cell adhesion molecules such as cadherins and link them to different cytoskeletal proteins depending on the type of cell junction. At the adherens...