Chemoattractant Receptors Activate Distinct Pathways for Chemotaxis and Secretion

Human leukocyte chemoattractant receptors activate chemotactic and cytotoxic pathways to varying degrees and also activate different G-proteins depending on the receptor and the cell-type. To determine the relationship between G-protein usage and the biological and biochemical responses activated, receptors for the chemoattractants formyl peptides (FR), platelet-activating factor (PAFR), and leukotriene B4 (BLTR) were transfected into RBL-2H3 cells. Pertussis toxin (Ptx) served as a Gαiinhibitor. These receptors were chosen to represent the spectrum of Gi usage as Ptx had differential effects on their ability to induce calcium mobilization, phosphoinositide hydrolysis, and exocytosis with complete inhibition of all responses by FR, intermediate effects on BLTR, and little effect on PAFR. Ptx did not affect ligand-induced phosphorylation of PAFR and BLTR but inhibited phosphorylation of FR. In contrast, chemotaxis to formylmethionylleucylphenylalanine, leukotriene B4, and platelet-activating factor was completely blocked by Ptx. Wortmannin, a phosphotidylinositol 3-kinase inhibitor, also completely blocked ligand-induced chemotaxis by all receptors but did not affect calcium mobilization or phosphoinositide hydrolysis; however, it partially blocked the exocytosis response to formylmethionylleucylphenylalanine and the platelet-activating factor. Membrane ruffling and pseudopod extension via the BLTR was also completely inhibited by both Ptx and wortmannin. These data suggest that of the chemoattractant receptors studied, G-protein usage varies with FR being totally dependent on Gi, whereas BLTR and PAFR utilize both Gi and a Ptx-insensitive G-protein. Both Ptx-sensitive and -insensitive G-protein usage can mediate the activation of phospholipase C, mobilization of intracellular calcium, and exocytosis by chemoattractant receptors. Chemotaxis, however, had an absolute requirement for a Gi-mediated pathway.

[1]  Terri L. Gilbert,et al.  Multiple activation steps of the N-formyl peptide receptor. , 1999, Biochemistry.

[2]  H. Bourne,et al.  Gαi Is Not Required for Chemotaxis Mediated by Gi-coupled Receptors* , 1999, The Journal of Biological Chemistry.

[3]  R. Lefkowitz,et al.  G protein-coupled receptor kinases. , 1998, Annual review of biochemistry.

[4]  I. Charo,et al.  Chemotaxis in a lymphocyte cell line transfected with C-C chemokine receptor 2B: Evidence that directed migration is mediated by βγ dimers released by activation of Gαi-coupled receptors , 1997 .

[5]  Henry R. Bourne,et al.  Receptors induce chemotaxis by releasing the βγ subunit of Gi, not by activating Gq or Gs , 1997 .

[6]  C. Der,et al.  Cdc42 and Rac1 induce integrin-mediated cell motility and invasiveness through PI(3)K , 1997, Nature.

[7]  R. Snyderman,et al.  Regulation of Human Chemokine Receptors CXCR4 , 1997, The Journal of Biological Chemistry.

[8]  V. Niggli,et al.  The phosphatidylinositol 3-kinase inhibitor wortmannin markedly reduces chemotactic peptide-induced locomotion and increases in cytoskeletal actin in human neutrophils. , 1997, European journal of pharmacology.

[9]  D. Zhelev,et al.  Transient increase of free cytosolic calcium during neutrophil motility responses. , 1997, Journal of cell science.

[10]  Gary M. Bokoch,et al.  Regulation of Actin Polymerization in Cell-free Systems by GTPγS and Cdc42 , 1997, The Journal of cell biology.

[11]  Takao Shimizu,et al.  A G-protein-coupled receptor for leukotriene B4 that mediates chemotaxis , 1997, Nature.

[12]  G. Johnson,et al.  Interleukin 8-stimulated phosphatidylinositol-3-kinase activity regulates the migration of human neutrophils independent of extracellular signal-regulated kinase and p38 mitogen-activated protein kinases. , 1997, Proceedings of the National Academy of Sciences of the United States of America.

[13]  N. Tapon,et al.  Rho, Rac and Cdc42 GTPases regulate the organization of the actin cytoskeleton. , 1997, Current opinion in cell biology.

[14]  I. Charo,et al.  Differential Regulation of G-protein-mediated Signaling by Chemokine Receptors* , 1996, The Journal of Biological Chemistry.

[15]  Huiping Jiang,et al.  Selective G Protein Coupling by C-C Chemokine Receptors (*) , 1996, The Journal of Biological Chemistry.

[16]  S. Zigmond,et al.  Signal transduction and actin filament organization. , 1996, Current opinion in cell biology.

[17]  R. Hochmuth,et al.  F-actin network formation in tethers and in pseudopods stimulated by chemoattractant. , 1996, Cell motility and the cytoskeleton.

[18]  P. Janmey,et al.  Thrombin receptor ligation and activated rac uncap actin filament barbed ends through phosphoinositide synthesis in permeabilized human platelets , 1995, Cell.

[19]  D. Kelvin,et al.  Interleukin-8 Receptor , 1995, The Journal of Biological Chemistry.

[20]  J. Benovic,et al.  Phosphorylation of the N-Formyl Peptide Receptor Carboxyl Terminus by the G Protein-coupled Receptor Kinase, GRK2 (*) , 1995, The Journal of Biological Chemistry.

[21]  R. Snyderman,et al.  Regulation of stably transfected platelet activating factor receptor in RBL-2H3 cells. Role of multiple G proteins and receptor phosphorylation. , 1994, The Journal of biological chemistry.

[22]  C. Gerard,et al.  The pro-inflammatory seven-transmembrane segment receptors of the leukocyte. , 1994, Current opinion in immunology.

[23]  R. Snyderman,et al.  Differences in phosphorylation of formylpeptide and C5a chemoattractant receptors correlate with differences in desensitization. , 1993, The Journal of biological chemistry.

[24]  Melvin I. Simon,et al.  G protein-coupled signal transduction pathways for interleukin-8. , 1993, Science.

[25]  M. Simon,et al.  Specific interactions of chemoattractant factor receptors with G-proteins. , 1993, The Journal of biological chemistry.

[26]  John I. Gallin,et al.  Inflammation: Basic Principles and Clinical Correlates , 1992 .

[27]  B. Dewald,et al.  Control of motility, exocytosis and the respiratory burst in human neutrophils. , 1991, Biochemical Society transactions.

[28]  R. Miller,et al.  Purification and characterization of Go alpha and three types of Gi alpha after expression in Escherichia coli. , 1990, The Journal of biological chemistry.

[29]  K. Forsyth.  Inflammation — Basic principles and clinical correlates: Gallin, J.I., Goldstein, I.M. and Snyderman, R. (Eds.) v + 995 pp. Raven Press, New York, 1988. $219.00, ISBN 0-88167-334-7 , 1989 .

[30]  R. Snyderman,et al.  Calcium influx stimulates a second pathway for sustained diacylglycerol production in leukocytes activated by chemoattractants. , 1988, Proceedings of the National Academy of Sciences of the United States of America.

[31]  S. Dahlén,et al.  Leukotrienes and lipoxins: structures, biosynthesis, and biological effects. , 1987, Science.

[32]  R. Snyderman,et al.  Role of a guanine nucleotide regulatory protein in the activation of phospholipase C by different chemoattractants. , 1987, Journal of immunology.

[33]  R. Snyderman,et al.  Model for Leukocyte Regulation by Chemoattractant Receptors: Roles of a Guanine Nucleotide Regulatory Protein and Polyphosphoinositide Metabolism , 1986, Journal of leukocyte biology.