Related Experiment Video

Updated: Aug 16, 2026

Spectral Karyotyping to Study Chromosome Abnormalities in Humans and Mice with Polycystic Kidney Disease
12:47

Spectral Karyotyping to Study Chromosome Abnormalities in Humans and Mice with Polycystic Kidney Disease

Published on: February 3, 2012

Retention of membrane-localized beta-catenin in cells lacking functional polycystin-1 and tuberin

Hiroyuki Kugoh1, Elena Kleymenova, Cheryl Lyn Walker

  • 1Department of Carcinogenesis, The University of Texas M. D. Anderson Cancer Center, Science Park-Research Division, Smithville, Texas 78957, USA.

Molecular Carcinogenesis
|March 1, 2002
PubMed

Insights

Loss of the tuberous sclerosis 2 (TSC2) tumor suppressor gene disrupts polycystin-1 and E-cadherin localization but preserves beta-catenin signaling in kidney cells.

Area of Science:

  • Cell Biology
  • Genetics
  • Nephrology

Background:

  • Tuberous sclerosis 2 (TSC2) encodes tuberin, crucial for polycystin-1 trafficking.
  • Polycystin-1, the product of Polycystic Kidney Disease 1 (PKD1), is implicated in autosomal dominant polycystic kidney disease.
  • Polycystin-1 and E-cadherin form a complex at adherens junctions, influencing cell adhesion and signaling.

Purpose of the Study:

  • To investigate the impact of tuberin deficiency on beta-catenin localization and signaling.
  • To determine if loss of polycystin-1 and E-cadherin membrane localization affects beta-catenin function.
  • To compare beta-catenin behavior in tuberin-null and tuberin-positive kidney cells.

Main Methods:

  • Characterization of beta-catenin localization and signaling in tuberin-null (EKT2, ERC15) and tuberin-positive (TRKE2) rat kidney epithelial cells.
  • Analysis of polycystin-1 and E-cadherin localization in the presence and absence of tuberin.
  • Assessment of gene transcription mediated by beta-catenin T-cell-specific transcription factor complexes.

Main Results:

  • Tuberin-null cells failed to properly localize polycystin-1 and E-cadherin at cell junctions.
  • Beta-catenin remained localized at the lateral cell membranes in both tuberin-null and tuberin-positive cells.
  • No significant differences in beta-catenin-mediated gene transcription were observed among the cell lines.

Conclusions:

  • Loss of Tsc2 tumor suppressor gene function impairs polycystin-1 localization and E-cadherin membrane presence.
  • Beta-catenin signaling remains functional and stable at the lateral cell membrane despite the absence of tuberin and proper polycystin-1/E-cadherin localization.
  • These findings suggest that beta-catenin signaling is retained in tuberin-null cells, even with disrupted cell junctional complexes.

More Related Videos

Reconstitution Of β-catenin Degradation In Xenopus Egg Extract09:41

Reconstitution Of β-catenin Degradation In Xenopus Egg Extract

Published on: June 18, 2014

Implementing Patch Clamp and Live Fluorescence Microscopy to Monitor Functional Properties of Freshly Isolated PKD Epithelium08:46

Implementing Patch Clamp and Live Fluorescence Microscopy to Monitor Functional Properties of Freshly Isolated PKD Epithelium

Published on: September 1, 2015

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...
Microtubules in Signaling01:22

Microtubules in Signaling

The primary cilium, made up of microtubules, acts as antennae on the cell surfaces for relaying external stimuli into the cells. These fine hair-like structures are present, generally one per cell. These are non-motile cilia in a 9+0 microtubules arrangement, where the central pair of microtubules are absent. The primary cilia arise from the basal body embedded in the cell membrane. Intraflagellar transport (IFT) carries requisite proteins from the cytoplasm to the cilium because the primary...
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...
Cadherins in Tissue Organization01:19

Cadherins in Tissue Organization

The cadherins are a superfamily of cell adhesion molecules comprising over 180 variants, with specific tissues expressing a particular combination of cadherin types. Cadherins generally exhibit homophilic binding; i.e., cadherins on one cell bind to cadherins of the same or closely related type on another cell. Thus, cells of the same type have a specific affinity to bind to each other and sort themselves into clusters to form tissues.
Cell Sorting During Development
Cell sorting plays an...
Tight Junctions01:29

Tight Junctions

Tight junctions are molecular seals between cells that prevent the leaking of fluids, ions, and other small solutes across cavities and compartments in multicellular organisms. They are mainly composed of claudin and occludin transmembrane proteins, and other proteins such as tricellulin and JAM (junctional adhesion molecule). All these proteins are 4-pass transmembrane proteins, except JAM, which is a single-pass transmembrane protein belonging to the immunoglobulin superfamily. The...
Tension Response at Adherens Junctions01:26

Tension Response at Adherens Junctions

The adherens junctions that anchor cells together are multi-protein complexes that dynamically adapt to mechanical stimuli such as tensile forces and shear stress. Mechanosensory proteins in these junctions can sense such mechanical stimuli and undergo a shift in their conformation, resulting in an altered function — a process called mechanotransduction.
α-Catenin as a Mechanosensory Protein
The α-catenin of adherens junctions is an allosteric protein with three VH (vinculin homology) domains...