The human alpha 3b is a 'full-sized' laminin chain variant with a widespread tissue expression than the truncated alpha 3a

We report the molecular cloning of the human laminin alpha 3b chain variant and its mRNA expression pattern in adult human tissues when compared to the alpha 3a variant. The mRNA encoding for the alpha 3b variant is about 11 kb and the predicted translation product carries the complete set of domains typical for a 'full-sized' laminin alpha chain. Apart from the similar domain structure of alpha 3b also the sequence of alpha 3 resulted more closely related to the alpha 5 than to the alpha 4 chain. Quantitative analysis of the RNA expression in a broad panel of adult human tissues indicated that the alpha 3b variant is more widely distributed than the alpha 3b shorter variant. (C) 1997 Federation of European Biochemical Societies.