Primary structure and expression of a novel human laminin α4 chain

AbstractThe complete primary structure of a novel human laminin α4 chain was derived from cDNA clones. The translation product contains a 24-residue signal peptide preceding the mature α4 chain of 1792 residues. The domain structure is similar to that of the recently described α3 chain [Ryan, Tizard, Van Devanter and Carter (1994) J. Biol. Chem. 269, 22779–22787]. Northern analysis of RNA from human fetal and adult tissues revealed developmental regulation of expression. In adult, strong expression was observed in heart as well as lung, ovary, small and large intestines, placenta and liver, whereas weak or no expression was detected in skeletal muscle, kidney, pancreas, testis, prostate or brain. In contrast, fetal lung and kidney revealed high expression. In situ hybridization analysis of human fetal and newborn tissues showed expression of the laminin in α4 chain in certain mesenchymal cells in tissues such as smooth muscle and dermis