Spatiotemporal Dynamics of Inositol 1,4,5-Trisphosphate That Underlies Complex Ca 2+ Mobilization Patterns

Abstract

Inositol 1,4,5-trisphosphate (IP 3 ) is a second messenger that elicits complex spatiotemporal patterns of calcium ion (Ca 2+ ) mobilization and has essential roles in the regulation of many cellular functions. In Madin-Darby canine kidney epithelial cells, green fluorescent protein–tagged pleckstrin homology domain translocated from the plasma membrane to the cytoplasm in response to increased concentration of IP 3 . The detection of translocation enabled monitoring of IP 3 concentration changes within single cells and revealed spatiotemporal dynamics in the concentration of IP 3 synchronous with Ca 2+ oscillations and intracellular and intercellular IP 3 waves that accompanied Ca 2+ waves. Such changes in IP 3 concentration may be fundamental to Ca 2+ signaling.