Leukotriene D(4) triggers an association between gbetagamma subunits and phospholipase C-gamma1 in intestinal epithelial cells

Research output: Contribution to journalArticle

Abstract

The proinflammatory mediator leukotriene D(4) (LTD(4)) binds to the seven-transmembrane receptor CYSLT(1). Although this leukotriene plays an important biological role, its intracellular signaling pathways are only partly known. In previous experiments, we found that LTD(4) induced tyrosine phosphorylation and translocation of phospholipase (PLC)-gamma1 to a plasma membrane fraction in a human epithelial cell line (Int 407). In the present study, we further examined these signaling events and found that LTD(4) induced a rapid interaction between Gbetagamma subunits and PLC-gamma1; results obtained with GST fusion proteins of PLC-gamma1 suggest that this interaction is mediated via the pleckstrin homology domain of PLC-gamma1. Moreover, LTD(4) induced an increased association of c-Src with PLC-gamma1, and the selective Src family tyrosine kinase inhibitor PP1 blocked both LTD(4)-induced tyrosine phosphorylation of PLC-gamma1 and the association of PLC-gamma1 with Gbetagamma subunits. The relevance of these observations in intracellular calcium signaling was investigated by microinjecting cells with anti-Gbeta, anti-PLC-gamma1, or anti-c-Src antibodies and by pretreatment with PP1. LTD(4)-induced calcium mobilization was blocked by each of the indicated antibodies (but not isotype-matched control antibodies) and by PP1. Our data suggest that Gbetagamma subunits can, directly or indirectly, serve as membrane-bound partners for PLC-gamma1 and c-Src and that each of these proteins is essential for LTD(4)-induced downstream PLC-gamma1 signaling.

Details

Authors
Organisations
External organisations
  • Lund University
  • Skåne University Hospital
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Cell Biology

Keywords

  • Calcium/metabolism, Calcium Signaling, Cells, Cultured, Epithelial Cells/cytology, GTP-Binding Proteins/metabolism, Humans, Intestinal Mucosa/metabolism, Isoenzymes/metabolism, Leukotriene D4/metabolism, Phospholipase C gamma, Protein Binding, Proto-Oncogene Proteins pp60(c-src)/metabolism, Type C Phospholipases/metabolism
Original languageEnglish
Pages (from-to)9849-53
Number of pages5
JournalJournal of Biological Chemistry
Volume275
Issue number13
Publication statusPublished - 2000 Mar 31
Publication categoryResearch
Peer-reviewedYes