Related Experiment Video

Updated: Jun 4, 2026

Studying TGF-β Signaling and TGF-β-induced Epithelial-to-mesenchymal Transition in Breast Cancer and Normal Cells
06:54

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

Published on: October 27, 2020

The TGF-β co-receptor, CD109, promotes internalization and degradation of TGF-β receptors

Albane A Bizet1, Kai Liu, Nicolas Tran-Khanh

  • 1Division of Plastic Surgery, Department of Surgery, McGill University, Montreal, QC, Canada.

Biochimica Et Biophysica Acta
|February 8, 2011
PubMed

Insights

CD109, a transforming growth factor-β (TGF-β) co-receptor, regulates TGF-β receptor endocytosis and degradation. This mechanism inhibits TGF-β signaling, impacting various pathological disorders like cancer.

Area of Science:

  • Cell biology
  • Molecular signaling
  • Cancer research

Background:

  • Transforming growth factor-β (TGF-β) signaling is crucial in numerous diseases, including cancer.
  • TGF-β receptor endocytosis pathways (clathrin-coated pits vs. caveolae) differentially regulate signaling and degradation.
  • CD109 was previously identified as a TGF-β co-receptor and negative regulator of TGF-β signaling.

Purpose of the Study:

  • To elucidate the mechanism by which CD109 regulates TGF-β receptor trafficking and signaling.
  • To investigate the association between CD109, caveolae, and TGF-β receptor endocytosis.

Main Methods:

  • Co-immunoprecipitation to assess CD109 and caveolin-1 association.
  • Confocal microscopy to visualize receptor localization.
  • Ligand-binding assays and receptor degradation studies.

Main Results:

  • CD109 associates with caveolin-1, a key component of caveolae.
  • CD109 enhances TGF-β binding to its receptors and promotes their caveolae-mediated internalization.
  • CD109 facilitates TGF-β receptor localization within caveolae and subsequent degradation, thereby inhibiting signaling.

Conclusions:

  • CD109 acts as a negative regulator of TGF-β signaling by modulating receptor endocytosis and degradation via the caveolae pathway.
  • Targeting CD109-mediated endocytosis could offer therapeutic strategies for TGF-β-related pathologies, including cancer.

More Related Videos

Visualization and Quantification of TGFβ/BMP/SMAD Signaling under Different Fluid Shear Stress Conditions using Proximity-Ligation-Assay11:38

Visualization and Quantification of TGFβ/BMP/SMAD Signaling under Different Fluid Shear Stress Conditions using Proximity-Ligation-Assay

Published on: September 14, 2021

Related Concept Videos

TGF - β Signaling Pathway01:16

TGF - β Signaling Pathway

The TGF-β signaling pathway regulates cell growth, differentiation, adhesion, motility, and development. TGF-β ligands that induce TGF-β signaling are synthesized in their latent form. Several proteases or cell surface receptors such as integrins act upon the latent form, releasing the active ligand. There are three types of mammalian TGF-βs: (TGF-β1, TGF-β2, and TGF-β3) that bind as homodimers or heterodimers to TGF-β receptors. The TGF-β receptors are of three kinds RI, RII, and RIII. The RI...
Receptor Downregulation in MVBs01:15

Receptor Downregulation in MVBs

Multivesicular bodies (MVBs) are mature endosomes that sort ubiquitinated proteins and then fuse with lysosomes to degrade the sorted proteins. Epidermal growth factor (EGF) and its receptor (EGFR) form a complex that can be internalized through endocytosis, sorted into an MVB, and later degraded.
The EGFR can initiate signaling pathways that  lead to cell proliferation, migration, and differentiation. Overexpression of EGFR  stimulates cells to proliferate. Excessive  EGFR activation may...
GPCR Desensitization01:12

GPCR Desensitization

G protein-coupled receptor (GPCR) signaling plays a crucial role in cell functioning. GPCR desensitization is an equally essential process. It allows cells to respond to changing environments and regain sensitivity to new stimuli while preventing unnecessary stimulation when no longer needed. Prolonged exposure to stimuli leads to GPCR desensitization. It involves blocking the receptors from binding and activating additional G proteins. This inhibits activation of downstream effectors, thereby...
Receptor-mediated Endocytosis01:38

Receptor-mediated Endocytosis

Overview
Receptor-mediated Endocytosis01:20

Receptor-mediated Endocytosis

Receptor-mediated endocytosis is when bulk amounts of specific molecules are imported into a cell after binding to cell surface receptors. The molecules bound to these receptors are taken into the cell through inward folding of the cell surface membrane, which is eventually pinched off into a vesicle within the cell. Structural proteins, such as clathrin, coat the budding vesicle.
Clathrin-Mediated Endocytosis of LDL
One well-characterized example of receptor-mediated endocytosis is the...
T Cell Activation and Clonal Selection01:22

T Cell Activation and Clonal Selection

T cells are integral to our adaptive immune system, recognizing and effectively responding to foreign antigens. T cell activation and clonal selection are pivotal in orchestrating this immune response. This article elucidates these mechanisms, detailing the roles of cluster of differentiation (CD) markers, major histocompatibility complex (MHC) molecules, costimulatory signals, and the process of clonal selection.
Naive T cells that have not yet encountered an antigen express two primary CD...