Overview Purpose allow cells to attach to each other via different types of cell-cell junctions allow cells to attach to the basement membrane complex interaction between cells and supporting matrix two divisions login to view 8 more bullets Types of molecules cadherin structure login to view 3 more bullets function login to view 2 more bullets selectin calcium dependent function login to view 1 more bullet subtypes login to view 14 more bullets integrin structure login to view 4 more bullets function login to view 8 more bullets Types of Cell-Cell Junctions Tight junctions aka zonula occludens structure zona occuldens (ZOs) 1, 2, 3 claudin proteins membrane spanning proteins login to view 2 more bullets location apical end of epithelial cells function prevent diffusion create cell membrane polarity Adherens junctions aka zonula adherens structure cadherin proteins login to view 1 more bullet location belt around cell login to view 1 more bullet Desmosomes aka macula adherens structure cadherin proteins login to view 2 more bullets keratin and desmoplakin proteins location distinct sites function rivets gives strength to junction between cells clinical importance pemphigus vulgaris login to view 14 more bullets Hemidesmosomes structure composed of integrins bind type IV collagen, fibronectin, laminin of basal lamina extracellularly bind intermediate filaments intracellularly function like a desmosome but instead of attaching cell-to-cell it attaches cell-to-basement membrane login to view 1 more bullet clinical importance bullous pemphigoid login to view 13 more bullets cancer login to view 1 more bullet Gap junctions structure pores formed by 6 connexon proteins function allow direct passage of small molecules from one cell to another login to view 1 more bullet role in electrical and metabolic signalling no role in strength