Epithelial Junctions

Epithelial Junctions

Cell junctions that connect adjacent epithelial cells.

Tight Junctions

Circumferential network of transmembrane proteins that bring the plasma membrane of adjacent cells closely together, forming an impermeable barrier.

Adherens Junctions

Transmembrane proteins that adhere adjacent cells to each other and to their actin microfilament cytoskeleton, regulating tension and shape.

Desmosomes

Spot-like junctions on the lateral surface between adjacent cells, anchored to intermediate filament cytoskeleton through protein plaques, providing very strong cell-cell adhesion.

Hemidesmosomes

Spot-like junctions on the basal surface between cells and the basement membrane, anchored to intermediate filament cytoskeleton through protein plaques, providing very strong cell-basement membrane adhesion.

Gap Junctions

Pore-like channels formed by transmembrane proteins on the cells' lateral surfaces, allowing communication between adjacent cells through the passage of small molecules and ions.

Occludin

A transmembrane protein involved in the formation of tight junctions, contributing to the impermeable barrier between adjacent cells.

Claudin

A transmembrane protein involved in the formation of tight junctions, contributing to the impermeable barrier between adjacent cells.

Microfilaments

Globular actin proteins assembled to form filaments, providing cell motility, tracks for the movement of motor proteins, and maintaining cell shape.

E-Cadherins

Transmembrane proteins involved in the formation of adherens junctions, adhering adjacent cells to each other and to their actin microfilament cytoskeleton.

Actin

A protein that forms part of the cytoskeleton and is involved in the regulation of cell shape and movement.

Intermediate Filaments

Multiple strands of fibrous proteins coiled together into strong rope-like filaments, providing high tensile strength to cells and maintaining shape.

Desmocollin

A transmembrane protein involved in the formation of desmosomes, contributing to strong cell-cell adhesion.

Desmoglein

A transmembrane protein involved in the formation of desmosomes, contributing to strong cell-cell adhesion.

Attachment Plaque

Protein plaques that anchor desmosomes and hemidesmosomes to the intermediate filament cytoskeleton.

Integrins

Transmembrane proteins involved in the formation of hemidesmosomes, anchoring cells to the basement membrane.

Basement Membrane

A thin, specialized extracellular matrix that separates epithelial cells from underlying connective tissue.

Bullous Pemphigoid

A blistering skin disease caused by autoantibodies attacking proteins in the basement membrane, leading to the separation of the epidermis from the dermis.

Connexon

A structure composed of six connexins, forming a closed or open channel in gap junctions.

Closed Channel

The state of a connexon in a gap junction when it does not allow the passage of small molecules and ions.

Open Channel

The state of a connexon in a gap junction when it allows the passage of small molecules and ions.

Intercalated Discs

Specialized cell-cell junctions found in cardiac muscle cells, containing gap junctions and adherens junctions.