Proceedings of The Physiological Society

University of Liverpool (2002) J Physiol 543P, S038

Communications

The role of actin in antigen-stimulated inositol 1,4,5-trisphosphate receptor clustering in RBL-2H3 cells

Mark Chalmers, Michael Schell and Peter Thorn

Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK

Cross-linking of IgE receptors (FCπRI) by multivalent antigens in basophils results in the activation of phospholipase C (PLC) and phosphatidylinositol 3-kinase (PI3K). PLC λ activation leads to the production of inositol 1,4,5-triphosphate (IP₃) and release of calcium from intracellular stores triggering exocytosis of secretory granules. Previous studies have shown that activation of the FCπRI leads to changes in IP₃ receptor (IP₃R) distribution in rat basophilic leukaemia cells (RBL-2H3), a mast cell line. At rest the IP₃R distribution is homogenous throughout the cell; upon activation the IP₃Rs cluster and form discrete spots of about 1 mm diameter (Wilson et al. 1998). We have examined the potential role of actin-myosin in this process.

In our experiments, RBL-2H3 cells were primed with anti-DNP-IgE (1 mg ml^-1) for 12

Where applicable, experiments conform with Society ethical requirements