RAT PANCREATIC LIPASE AND 2 RELATED PROTEINS - ENZYMATIC-PROPERTIES AND MESSENGER-RNA EXPRESSION DURING DEVELOPMENT

We report the cDNA sequences of rat colipase, rat pancreatic lipase (r PL), and a rat pancreatic lipase-related protein (rPLRP). Comparison t o the human PLRP cDNA suggests that the isolated clone encodes rPLRP-2 . Both cDNA and a third cDNA encoding rPLRP-1 are secreted from Sf9 ce lls infected with recombinant baculovirus. rPL and rPLRP-2 hydrolyze t riolein, 8.0 and 4.4 mu mol.min(-1).mu g(-1), respectively. They are i nhibited by bile salts, and activity is restored by (pro)colipase. PLR P-1 has barely detectable activity against triolein, even with (pro)co lipase present. The pattern of mRNA expression during development in t he rat reveals that all mRNA are low in the fetal rat pancreas. Both P LRP mRNA rise just before birth to a maximum 12 h after birth. They fa ll to low levels in the adult. In contrast, the PL mRNA is low at birt h and rises rapidly during the suckling-weanling transition. In conclu sion, the rat has at least three genes encoding different lipases, and these related genes have separate regulatory controls.