Related Experiment Video
Updated: Aug 10, 2026

Analysis of Protein-protein Interactions and Co-localization Between Components of Gap, Tight, and Adherens Junctions in Murine Mammary Glands
Published on: May 30, 2017
JAM4, a junctional cell adhesion molecule interacting with a tight junction protein, MAGI-1
Susumu Hirabayashi1, Makiko Tajima, Ikuko Yao
1Department of Medical Biochemistry, Graduate School of Medicine, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo 113-8519, Japan.
Junctional adhesion molecule 4 (JAM4) interacts with MAGI-1, forming a novel protein complex at tight junctions. This JAM4-MAGI-1 complex enhances cell adhesion and regulates epithelial barrier function.
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- MAGI-1 is a scaffold protein at epithelial tight junctions.
- Understanding proteins at tight junctions is crucial for epithelial barrier function.
Purpose of the Study:
- To identify novel MAGI-1 binding proteins.
- To characterize the function of JAM4 in epithelial cells.
Main Methods:
- Co-immunoprecipitation assays to detect protein interactions.
- Immunofluorescence microscopy to determine protein localization.
- Cell adhesion and permeability assays in cultured cells.
Main Results:
- JAM4 was identified as a novel MAGI-1 binding protein.
- JAM4 mediates calcium-independent homophilic adhesion.
- The JAM4-MAGI-1 complex enhances cell adhesion and reduces epithelial permeability.
Conclusions:
- JAM4 and MAGI-1 form a functional complex at tight junctions.
- This complex plays a role in regulating epithelial barrier integrity.
- The JAM4-MAGI-1 machinery may be important for kidney glomerulus and intestinal epithelial cell function.
More Related Videos
12:15The C. elegans Intestine As a Model for Intercellular Lumen Morphogenesis and In Vivo Polarized Membrane Biogenesis at the Single-cell Level: Labeling by Antibody Staining, RNAi Loss-of-function Analysis and Imaging
Published on: October 3, 2017
09:37Immunostaining and Dye Penetration Experiments to Define Core Pleated Septate Junction Proteins in Drosophila Embryonic Epithelia
Published on: February 27, 2026
Related Concept Videos
Anchoring Junctions
Overview of Cell-Cell Junctions
Occluding or Tight Junctions
Tight...
Adherens Junctions
Adherens Junctions are Dynamic
The endothelial cells...
Tight Junctions
Immunoglobulin-like Cell Adhesion Molecules
Ig-CAMs exhibit either homophilic binding (to other Ig-CAMs) or heterophilic binding (to other ligands such as integrins). While most Ig-CAMs...
Overview of Cell-Cell Junctions
Occluding or Tight Junctions
Tight...