Molecular Characterization of Murine Pancreatic Phospholipase A 2

Abstract

The pancreatic secretory phospholipase A₂ (sPLA₂IB) is considered to be a digestive enzyme, although it has several important receptor-mediated functions. In this study, using the newly isolated murine sPLA₂IB cDNA clone as a probe, we demonstrate that in addition to the pancreas, the sPLA₂IB mRNA was expressed in extrapancreatic organs such as the liver, spleen, duodenum, colon, and lungs. We also demonstrate that sPLA₂IB mRNA expression was detectable from the 17^th day of gestation in the developing mouse fetus, coinciding with the time of completion of differentiation of the pancreas. Furthermore, the mRNA expression pattern of sPLA₂IB was distinct from those of sPLA₂IIA and cPLA₂ in various tissues examined. The murine sPLA₂IB gene structure is well conserved, consistent with findings in other mammalian species, and this gene mapped to the region of mouse chromosome 5F1-G1.1. Taken together, our results suggest that sPLA₂IB plays important roles both in the pancreas and in extrapancreatic tissues and that in the mouse, its expression is developmentally regulated.