The American journal of the medical sciences
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The majority of cell adhesive events to the extracellular matrix are mediated by cell surface receptors, beta 1 integrins. Keratinocytes express at least six different polypeptides of beta 1 integrin class, namely beta 1, alpha 2, alpha 3, alpha 5, and alpha 6 (alpha 6 is mainly associated with beta 4 polypeptide). These epithelial cells use alpha 2 beta 1 as a collagen receptor and alpha 3 beta 1 as a fibronectin receptor, while alpha 6 beta 4 is the major basement membrane receptor. ⋯ Processing of beta 1 integrins is fast in keratinocytes; half-maximal maturation takes only 3 hours. In addition to their function in cell-matrix interactions, beta 1 integrins (alpha 2 beta 1 and alpha 3 beta 1) have also a role in maintaining keratinocyte cell-cell interactions. It is possible that resting basal keratinocytes use beta 1 integrins as cell-cell adhesion receptors, and during activation, like in wound healing, these receptors relocalize to mediate events involving cell-matrix interactions.