Abstract

Cytosolic phospholipase A2(cPLA2), an enzyme responsible for the generation of arachidonic acid, is located in the cytosolic compartment in most tissues and it translocates to membrane compartments when activated. We found that cPLA2 distribution in pancreatic β-cells is different from that of most other mammalian cells: it is evenly distributed throughout the β-cell, in both cytoplasmic and nuclear compartments. Agents that increased intracellular Ca2+ in the MIN6 β-cell line also stimulated a redistribution of cPLA2 immunoreactivity such that the majority of the enzyme moved from the nucleus to the cytoplasm. The time course of events was compatible with the elevation in Ca2+ being responsible for translocation of cPLA2. These observations suggest that cPLA2 may be compartmentalised in unstimulated β-cells, perhaps to limit its access to substrate prior to elevations in intracellular Ca2+. © 2002 Elsevier Science (USA). All rights reserved.