
Laminins arehigh-molecularweight (~400kDa)proteinsofthe extracellularmatrix. Theyareanimportantandbiologicallyactivepartofthebasallamina,whichis oneofthelayersofthe basementmembrane,aproteinnetworkfoundationformostcellsandorgans,influencingcelldifferentiation,migration,andadhesion. Lamininsareheterotrimericproteinsthatcontainanα-chain,aβ-chain,andaγ-chain.Thedistributionofthedifferentlamininisoformsistissue-specific.Thelamininmoleculesarenamedaccordingtotheirchaincomposition.
Laminin-111isoneof thefirst laminin isoformstobe discovered. The“111”identifiestheisoform’schaincompositionofα1β1γ1.Laminin-111ispredominantlyexpressedintheembryonicepithelium,butcanalsobefoundinsomeadultepitheliumsuchasthe kidney,liver, testis, ovaries,andbrain bloodvessels. Laminin-111hasbeenidentifiedasacrucialmoleculefordevelopmentoftheembryo,geneticablationoflaminin-111resultsinembryonicdeath.