Molecular cloning and tissue-specific expression of a novel murine laminin gamma3 chain.

A novel laminin gamma3 chain was identified from the expressed sequence tag data base at the National Center for Biotechnology Information. A complete cDNAderived peptide sequence reveals a 1592-amino acid-long primary translation product, including a tentative 33-amino acid-long signal peptide. Comparison with the laminin gamma1 chain predicts that the two polypeptides have equal spatial dimensions. In addition, the well conserved domains VI and III(LE4) predict that gamma3 containing laminins are able to integrate to the laminin network and also via nidogen connect to other protein networks in the basement membranes. Combination of Northern analysis and in situ hybridization experiments indicate that expression of the gamma3 chain is highly tissue- and cell-specific, being significantly strong in capillaries and arterioles of kidney as well as in interstitial Leydig cells of testis.