Cell Adhesion and Junctional Complexes

Flashcards on cell adhesion and junctional complexes including extracellular matrix, types of junctions, and cell adhesion molecules.

Epithelium

Cells are tightly packed, binding to each other

Mesenchyme

Cells are sparse

Basement membrane/basal lamina

2D sheet on which epithelial cells reside

Fibrillar matrix

3D matrix composed of various fibers, in which cells such as fibroblasts are buried.

Basement membrane/basal lamina

Underlies epithelia and surrounds some non-epithelial cells. Main components: Collagen IV, Laminin, Nidogen, Perlecan.

Fibrillar matrix

Deposited and constantly re-modelled by embedded cells. Main components: Collagen I, Fibronectin, Elastin, Proteoglycans.

Desmosomes

Pairs of dark, disk/button-like structures at cell-cell contacts

Hemidesmosomes

Something looking like ‘half-desmosomes’ at cell-ECM interface

Tight Junction

Junctional complex that surrounds the apical surface of epithelial cells.

Gap Junction

Junctional complex coupled cells via permeable pores

Adherens Junction

Junctional complex linked to the actin cytoskeleton

Focal Adhesion

Junctional complex that links the actin cytoskeleton to the ECM via integrins

Cadherins

Cell adhesion molecules that are Ca2+-dependent

E-cadherin

Classical cadherin found in many epithelia

N-cadherin

Classical cadherin found in neurons, heart, skeletal muscle, lens, and fibroblasts

P-cadherin

Classical cadherin found in placenta, epidermis, breast epithelium

VE-cadherin

Classical cadherin found in endothelial cells