Signaling and cross-talk by C5a and UDP in macrophages selectively use PLCbeta3 to regulate intracellular free calcium.

ABSTRACT: Studies in fibroblasts, neurons, and platelets have demonstrated the integration of signals from different G protein-coupled receptors (GPCRs) in raising intracellular free Ca(2+). To study signal integration in macrophages, we screened RAW264.7 cells and bone marrow-derived macrophages (BMDM) for their Ca(2+) response to GPCR ligands. We found a synergistic response to complement component 5a (C5a) in combination with uridine 5'-diphosphate (UDP), platelet activating factor (PAF), or lysophosphatidic acid (LPA). The C5a response was Galpha(i)-dependent, whereas the UDP, PAF, and LPA responses were Galpha(q)-dependent. Synergy between C5a and UDP, mediated by the C5a and P2Y6 receptors, required dual receptor occupancy, and affected the initial release of Ca(2+) from intracellular stores a

SUBMITTER: Roach TI 

PROVIDER: S-EPMC2427365 | biostudies-literature | 2008 Jun

REPOSITORIES: biostudies-literature