Related Experiment Video

Updated: Jun 14, 2026

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

Reconstitution Of β-catenin Degradation In Xenopus Egg Extract

Published on: June 17, 2014

Homeodomain-interacting protein kinase 2 (HIPK2) targets beta-catenin for phosphorylation and proteasomal degradation

Eun-A Kim1, Ji Eon Kim, Ki Sa Sung

  • 1Department of Biological Science, Sungkyunkwan University, Suwon 440-746, Republic of Korea.

Biochemical and Biophysical Research Communications
|March 24, 2010
PubMed

Insights

Homeodomain-interacting protein kinase 2 (HIPK2) negatively regulates Wnt/beta-catenin signaling. HIPK2 promotes beta-catenin degradation, inhibiting Wnt target gene activation and cell proliferation, thus impacting tumor formation.

Area of Science:

  • Molecular Biology
  • Cell Signaling
  • Cancer Research

Background:

  • The Wnt/beta-catenin pathway is crucial for cell signaling and gene activation.
  • Intracellular beta-catenin levels are tightly regulated within this cascade.

Purpose of the Study:

  • To investigate the role of homeodomain-interacting protein kinase 2 (HIPK2) in regulating Wnt/beta-catenin signaling.
  • To elucidate the mechanism by which HIPK2 affects beta-catenin stability and activity.

Main Methods:

  • Knock-down of endogenous HIPK2 in vivo and in cultured cells.
  • Analysis of beta-catenin stability, nuclear localization, and TCF/LEF-mediated gene activation.
  • Site-directed mutagenesis of beta-catenin phosphorylation sites (Ser33 and Ser37).
  • Ex vivo mouse models and Xenopus embryo experiments.

Main Results:

  • HIPK2 functions as a negative regulator of the Wnt/beta-catenin pathway.
  • HIPK2-mediated phosphorylation of beta-catenin at Ser33/Ser37 induces its degradation.
  • HIPK2 knockdown enhances beta-catenin stability, nuclear accumulation, Wnt target gene expression, and cell proliferation.
  • HIPK2 knockdown potentiates beta-catenin-mediated tumor formation in mice.
  • HIPK2 inhibits beta-catenin-induced developmental abnormalities in Xenopus.

Conclusions:

  • HIPK2 negatively regulates Wnt/beta-catenin signaling by promoting beta-catenin phosphorylation and proteasomal degradation.
  • HIPK2 acts as a tumor suppressor by limiting beta-catenin-driven proliferation and tumor formation.
  • HIPK2 represents a novel therapeutic target for Wnt/beta-catenin-driven cancers.

More Related Videos

Identification of Cyclin-dependent Kinase 1 Specific Phosphorylation Sites by an In Vitro Kinase Assay12:26

Identification of Cyclin-dependent Kinase 1 Specific Phosphorylation Sites by an In Vitro Kinase Assay

Published on: May 3, 2018

Identification of Novel CK2 Kinase Substrates Using a Versatile Biochemical Approach11:11

Identification of Novel CK2 Kinase Substrates Using a Versatile Biochemical Approach

Published on: February 21, 2019

Related Concept Videos

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...
PI3K/mTOR/AKT Signaling Pathway01:22

PI3K/mTOR/AKT Signaling Pathway

The mammalian target of rapamycin  (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1  (mTORC1) and mTOR complex 2  (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast,  mTORC2 consists of a rapamycin-insensitive companion...
Regulated Protein Degradation02:58

Regulated Protein Degradation

It is vital to regulate the activity of enzymatic as well as non-enzymatic proteins inside the cell. This can be achieved either through creating a balance between their rate of synthesis and degradation or regulating the intrinsic activity of the protein. Both these regulation mechanisms play an essential role in the normal functioning of cells.
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
Regulated Protein Degradation02:58

Regulated Protein Degradation

It is vital to regulate the activity of enzymatic as well as non-enzymatic proteins inside the cell. This can be achieved either through creating a balance between their rate of synthesis and degradation or regulating the intrinsic activity of the protein. Both these regulation mechanisms play an essential role in the normal functioning of cells.
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
Anaphase Promoting Complex00:50

Anaphase Promoting Complex

The stepwise destruction of specific proteins is necessary for the progression and completion of the cell cycle. Such proteins are ubiquitinated by ubiquitin ligases and then subsequently destroyed by the proteasome. The SCF (Skp1/Cullin/F-box) and the anaphase-promoting complex (APC) are two important ubiquitin ligases involved in cell cycle progression. While SCF is active throughout the cell cycle, APC gets activated during metaphase to anaphase transition. Cdc20 or Cdh1 binds to APC and...
MAPK Signaling Cascades01:07

MAPK Signaling Cascades

Mitogen-activated protein kinase, or MAPK pathway, activates three sequential kinases to regulate cellular responses such as proliferation, differentiation, survival, and apoptosis. The canonical MAPK pathway starts with a mitogen or growth factor binding to an RTK. The activated RTKs stimulate Ras, which recruits Raf or MAP3 Kinase (MAPKKK), the first kinase of the MAPK signaling cascade. Raf further phosphorylates and activates MEK or MAP2 Kinases (MAPKK), which in turn phosphorylates MAP...