Entactin, basement membranes

Laminin [consisting of three polypeptide chains, A, Bl (possibly replaced in GBM by S) and B2] is the most important noncollagenous protein of the glomerular basement membrane. Laminin forms a second network, which is connected to the collagen IV network probably via another protein called entactin or nidogen. Laminin is probably very important for cellular differentiation and adhesion, but its mesh clearly also contributes to the structure of the glomerular basement membrane. The postnatally common embryonic laminin-10 isoform is... 

Cell attachment to the glomerular basement membrane is mediated by laminin, entactin, and fibronectin, at least partly through integrin receptors on the cell surface of both endothelial and visceral epithelial cells. 

A ubiquitous laminin-associated glycoprotein is entactin (also known as nidogen), a glycoprotein now thought to provide linkage between laminin and type IV collagen in basement membranes. 

Sannes PL, Burch KK, Khosla J, McCarthy KJ, Couchman JR. Immunohis-tochemical localization of chondroitin sulfate, chondroitin sulfate proteoglycan, heparan sulfate proteoglycan, entactin, and laminin in basement membranes of postnatal developing and adult rat lungs. Am J Respir Cell Mol Biol 1993 8 245-251. 

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