Junction | Location | Composition | Function | Remarks |
Tight junction (Zonula occludens) | Epithelial cell-Epithelial cell | Claudin and Occludin (attaches to cytoskeleton – actin filament) | Prevents paracellular movement of solutes and diffusion | |
Adherens junction (Zonula adherens) | Epithelial cell-Epithelial cell | E-cadherin (attaches to cytoskeleton – actin filament) | Belt desmosome (Anchoring) | Cadherins are Ca2+ depndend adhesion proteins Loss of E-cadherin promotes metastasis |
Desmosome | Epithelial cell-Epithelial cell | Cadherins – Desmoglein, Desmocollin and Desmoplakin (attaches to cytoskeleton – intermediate filaments) | Desmoglein – connects keratinocytes in Stratum spinosum Structural support | Autoantibody to: 1. Desmoglein-1: Pemphigus foliaceous (only skin lesion) 2. Desmogelin-1 (skin) and/or Desmoglein-3 (mucosal): Pemphigus vulgaris |
Gap junction | Epithelial cell-Epithelial cell | Connexons | Electrical and chemical communication | Connexin-43 are the main gap-junction proteins in myocardium and myometrium |
Hemidesmosome | Epithelial cell-Basement membrane | Integrins (attaches to laminim or fibronectin and type IV collagen) | Integrity of basolateral membrane | Autoantibodies to hemidesmosome (BP-Ag1 and BP-Ag2): Bullous pemphigoid |