Related Experiment Video

Updated: Jan 20, 2026

Tight Junctions
01:29

Tight Junctions

7.0K

Claudins and JAM-A coordinately regulate tight junction formation and epithelial polarity

Tetsuhisa Otani1,2, Thanh Phuong Nguyen1,2, Shinsaku Tokuda3

  • 1Division of Cell Structure, National Institute for Physiological Sciences, Okazaki, Aichi, Japan.

The Journal of Cell Biology
|August 31, 2019
PubMed

Insights

Tight junctions (TJs) are crucial for epithelial barriers. Claudins and JAM-A coordinate TJ formation and epithelial polarity, clarifying their distinct roles in barrier function.

Area of Science:

  • Cell Biology
  • Epithelial Biology
  • Membrane Protein Function

Background:

  • Tight junctions (TJs) are critical for epithelial barrier function and polarity.
  • The precise roles of TJ components, such as claudins and scaffolding proteins (ZO-1/ZO-2), in TJ organization and polarity remain incompletely understood.

Purpose of the Study:

  • To elucidate the distinct and cooperative roles of TJ components, including claudins, ZO-1/ZO-2, and JAM-A, in the formation of TJ structures, epithelial barriers, and epithelial polarity.

Main Methods:

  • Systematic knockout of TJ components using genome editing in epithelial cells.
  • Assessment of TJ structure, epithelial barrier integrity (paracellular permeability to electrolytes and macromolecules), and epithelial polarity.

Main Results:

  • ZO-1/ZO-2 deficiency abolished TJ structures and epithelial barriers.
  • Claudin deficiency disrupted TJ strands and the electrolyte barrier but preserved membrane appositions and the macromolecule barrier, without affecting epithelial polarity.
  • Simultaneous knockout of claudins and JAM-A led to loss of membrane appositions, macromolecule barrier defects, and sporadic polarity issues.

Conclusions:

  • Claudins and ZO-1/ZO-2 play distinct roles in TJ formation and barrier function.
  • Claudins and JAM-A cooperate to establish TJ-mediated membrane appositions and regulate epithelial polarity.

More Related Videos

Analysis of Protein-protein Interactions and Co-localization Between Components of Gap, Tight, and Adherens Junctions in Murine Mammary Glands11:31

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

10.4K
Functional Assessment of Intestinal Tight Junction Barrier and Ion Permeability in Native Tissue by Ussing Chamber Technique06:43

Functional Assessment of Intestinal Tight Junction Barrier and Ion Permeability in Native Tissue by Ussing Chamber Technique

Published on: May 26, 2021

6.3K

Related Concept Videos

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...
7.0K
Analysis of Protein-protein Interactions and Co-localization Between Components of Gap, Tight, and Adherens Junctions in Murine Mammary Glands11:31

Analysis of Protein-protein Interactions and Co-localization Between Components of Gap, Tight, and Adherens Junctions in Murine Mammary Glands

Intercellular junctions are requisites for mammary gland stage-specific functions and development. This manuscript provides a detailed protocol for the study of protein-protein interactions (PPIs) and co-localization using murine mammary glands. These techniques allow for the investigation of the dynamics of the physical association between intercellular junctions at different developmental stages.
10.4K
Polar and Cylindrical Coordinates01:22

Polar and Cylindrical Coordinates

The Cartesian coordinate system is a very convenient tool to use when describing the displacements and velocities of objects and the forces acting on them. However, it becomes cumbersome when we need to describe the rotation of objects. So, when describing rotation, the polar coordinate system is generally used.
19.8K
Functional Assessment of Intestinal Tight Junction Barrier and Ion Permeability in Native Tissue by Ussing Chamber Technique06:43

Functional Assessment of Intestinal Tight Junction Barrier and Ion Permeability in Native Tissue by Ussing Chamber Technique

Intestinal epithelium confers not only nutrient absorption but protection against noxious substances. The apical-most epithelial intercellular junction, i.e., the tight junction, regulates paracellular solute and ion permeability. Here, a protocol for the preparation of mucosal sheets and assessment of the ion selectivity of tight junctions using Ussing chamber technique is...
6.3K
Curvilinear Motion: Polar Coordinates01:27

Curvilinear Motion: Polar Coordinates

In polar coordinates, the motion of a particle follows a curvilinear path. The radial coordinate symbolized as 'r,' extends outward from a fixed origin to the particle, while the angular coordinate, 'θ,' measured in radians, represents the counterclockwise angle between a fixed reference line and the radial line connecting the origin to the particle.
The particle's location is described using a unit vector along the radial direction. Deriving the particle's position...
883
Analyzing the Function of Small GTPases by Microinjection of Plasmids into Polarized Epithelial Cells09:38

Analyzing the Function of Small GTPases by Microinjection of Plasmids into Polarized Epithelial Cells

This article details the procedures involved in overexpression and analysis of small GTPases in polarized epithelial cells using microinjection...
11.9K