Membrane type-serine protease 1 (MT-SP1) plays potential roles in the proce
ss of invasion and metastasis of carcinomas. In the present study, we clone
d a rat MT-SP1 cDNA and investigated the intestinal distribution and proteo
lytic properties of the enzyme. By in situ hybridization we found the promi
nent expression of the mRNA in the epithelial layer of the small intestinal
upper villi and of the colon, where cells are loosely attached to the base
ment membrane. When MT-SP1 was expressed in Caco-2, a colonic carcinoma cel
l line, the protein was localized exclusively on the basolateral side. A se
creted form of the enzyme produced in COS-1 cells digested fibronectin and
laminin. These findings suggest that MT-SP1 participates in the control of
intestinal epithelial turnover by regulating the cell-substratum adhesion.
(C) 2001 Academic Press.