N-Formyl Peptide Receptor Ligation Induces Rac-dependent Actin Reorganization through Gβγ Subunits and Class Ia Phosphoinositide 3-Kinases

Belisle, Barbara; Abo, Arie

doi:10.1074/jbc.m002743200

Cited by 25 publications

(30 citation statements)

References 37 publications

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“…It has been well documented that G␤␥ subunits induce activation of Rho family GTPases in a variety of cells and tissues (19,20,29,30). Because there is increasing evidence that such activation occurs independently of the phospholipase C/protein kinase C pathway, it is most likely that hitherto unidentified RhoGEFs are involved.…”

Section: Discussionmentioning

confidence: 99%

Heterotrimeric G Protein βγ Subunits Stimulate FLJ00018, a Guanine Nucleotide Exchange Factor for Rac1 and Cdc42

Ueda

Nagae

Kozawa

et al. 2008

Journal of Biological Chemistry

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We previously reported that G␤␥ signaling regulates cell spreading or cell shape change through activation of a Rho family small GTPase, suggesting the existence of a G␤␥-regulated Rho guanine-nucleotide exchange factor (RhoGEF). In this study we examined various RhoGEF clones, found FLJ00018 to be a G␤␥-activated RhoGEF, and investigated the molecular mechanism of G␤␥-induced activation of Rho family GTPases. Co-expression of the genes for FLJ00018 and G␤␥ enhanced serum response element-mediated gene transcription in HEK-293 cells. Combined expression of G␤␥ and FLJ00018 significantly induced activation of Rac and Cdc42 but not RhoA. FLJ00018 also enhanced gene transcription induced by carbachol-stimulated m2 muscarinic acetylcholine receptor, and this enhancement was blocked by pertussis toxin. Furthermore, we demonstrated G␤␥ to interact directly with the N-terminal region of FLJ00018 and the N-terminal fragment of this molecule to inhibit serum response element-dependent transcription induced by G␤␥/FLJ00018 and carbachol. In NIH3T3 cells, FLJ00018 enhanced lysophosphatidic acid-induced cell spreading, which was also blocked by the N-terminal fragment of FLJ00018. These results provide evidence for a signaling pathway by which G i -coupled receptor specifically induces Rac and Cdc42 activation through direct interaction of G␤␥ with FLJ00018.Rho family small GTPases belong to the Ras superfamily, comprise more than 20 distinct proteins, and control a wide variety of cellular processes. First identified as regulators of the actin cytoskeleton rearrangements, RhoA, Rac1, and Cdc42 induce stress fibers, lamellipodia, and filopodia formation, respectively, and it is now clear that Rho family proteins play pivotal roles in cell migration, outgrowth, extension and pathfinding of neuritis, and gene transcription. Like other small GTPases, Rho GTPases cycle between an inactive GDP-bound state and an active GTP-bound state (1, 2). This cycling of Rho GTPases is controlled by three distinct classes of regulatory proteins, namely (i) guanine-nucleotide dissociation inhibitors, which stabilize the inactive form (3), (ii) guanine-nucleotide exchange factors (GEFs), 2 which catalyze GDP/GTP exchange (4, 5), and (iii) GTPases-activating proteins, which stimulate low, intrinsic GTPase activity of Rho GTPases (6). In particular, 60 different GEFs for Rho family members (RhoGEFs) have been described so far (4). A common feature of RhoGEFs is the Dbl homology (DH) domain responsible for exchange activity followed by a pleckstrin homology (PH) domain considered to be involved in subcellular localization. Besides this tandem motif, RhoGEFs often contain one or more additional signal transduction domains, such as PDZ, Src homology (SH) 2, SH3, and RGS (regulator of G protein signaling), which can function as molecular bridges between different signal transduction pathways.It is well established that a large variety of G protein-coupled receptors (GPCRs), particularly those coupling to the G 12/13 type of heterotrimeric G proteins...

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Section: Discussionmentioning

confidence: 99%

Heterotrimeric G Protein βγ Subunits Stimulate FLJ00018, a Guanine Nucleotide Exchange Factor for Rac1 and Cdc42

Ueda

Nagae

Kozawa

et al. 2008

Journal of Biological Chemistry

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“…2). FPR ligation has also been shown to signal through the small G protein Cdc42 to activate Rac-and ARP2/3-dependent pathways leading to actin nucleation (3,4). The culmination of these signaling events triggers morphological and biochemical alterations including polarization of the actin cytoskeleton, activation of various integrins, and directed migration.…”

Section: Expression and Function Of Formyl Peptide Receptors Onmentioning

confidence: 99%

“…Formylated peptides bind to the high affinity formyl peptide receptor (FPR) 3 and/or the low affinity formyl peptide receptor-like-1 (FPRL1) (1). These receptors are seven transmembrane pertussis toxin-sensitive G protein-coupled receptors.…”

Section: Expression and Function Of Formyl Peptide Receptors Onmentioning

confidence: 99%

“…Activation of neutrophil FPR with fMLP stimulates disassociation of G ␤␥ , signaling a phosphatidylinositol 3-kinase and Rac-dependent increase in F-actin and redistribution of the cytoskeleton leading to polarization and formation of lamellopodia and filopodia (3,4,27,28). To determine whether fMLP induces actin polymerization in fibroblasts, cells were treated with fMLP for 0 -60 s, fixed, stained for F-actin, and assayed by fluorescence spectrophotometer.…”

Section: Fmlp Stimulates a Transient Increases In And Reorganization mentioning

confidence: 99%

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Expression and Function of Formyl Peptide Receptors on Human Fibroblast Cells

VanCompernolle

Clark

Rummel

et al. 2003

The Journal of Immunology

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The migration of polymorphonuclear leukocytes from the blood to sites of infection in tissues is a hallmark of the innate immune response. Formylated peptides produced as a byproduct of bacterial protein synthesis are powerful chemoattractants for leukocytes. Formyl peptides bind to two different G protein-coupled receptors (formyl peptide receptor (FPR) and the low affinity formyl peptide receptor-like-1 (FPRL1)) to initiate a signal transduction cascade leading to cell activation and migration. Our analysis of expressed sequences from many cDNA libraries draws attention to the fact that FPRs are widely expressed in nonlymphoid tissues. Here we demonstrate that FPRs are expressed by normal human lung and skin fibroblasts and the human fibrosarcoma cell line HT-1080. The expression on fibroblasts of receptors for bacteria-derived peptides raises questions about the possible function of these receptors in nonleukocyte cells. We studied the function of FPRs on fibroblasts and find that stimulation with fMLP triggers dose-dependent migration of these cells. Furthermore, fMLP induces signal transduction including intracellular calcium flux and a transient increase in F-actin. The fMLP-induced adhesion and motility of fibroblasts on fibronectin require functional protein kinase C and phosphatidylinositol 3-kinase. This first report of a functional formyl peptide receptor in cells of fibroblast origin opens new possibilities for the role of fibroblasts in innate immune responses.

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“…Directional migration, however, requires the activity of G␤␥, but not G␣, proteins (1,2). In addition, Rho family guanosine triphosphatases (GTPases), the phosphoinositide 3-kinases, and possibly extracellular receptor kinases each play important roles in generating the cell polarity and cytoskeletal reorganization required for directional migration (3)(4)(5)(6)(7).…”

mentioning

confidence: 99%

Defective lymphocyte chemotaxis in β-arrestin2- and GRK6-deficient mice

Fong

Premont

Richardson

et al. 2002

Proc. Natl. Acad. Sci. U.S.A.

279

233

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Lymphocyte chemotaxis is a complex process by which cells move within tissues and across barriers such as vascular endothelium and is usually stimulated by chemokines such as stromal cell-derived factor-1 (CXCL12) acting via G protein-coupled receptors. Because members of this receptor family are regulated (''desensitized'') by G protein-coupled receptor kinase (GRK)-mediated receptor phosphorylation and ␤-arrestin binding, we examined signaling and chemotactic responses in splenocytes derived from knockout mice deficient in various ␤-arrestins and GRKs, with the expectation that these responses might be enhanced. Knockouts of ␤-arrestin2, GRK5, and GRK6 were examined because all three proteins are expressed at high levels in purified mouse CD3؉ T and B220؉ B splenocytes. CXCL12 stimulation of membrane GTPase activity was unaffected in splenocytes derived from GRK5-deficient mice but was increased in splenocytes from the ␤-arrestin2-and GRK6-deficient animals. Surprisingly, however, both T and B cells from ␤-arrestin2-deficient animals and T cells from GRK6-deficient animals were strikingly impaired in their ability to respond to CXCL12 both in transwell migration assays and in transendothelial migration assays. Chemotactic responses of lymphocytes from GRK5-deficient mice were unaffected. Thus, these results indicate that ␤-arrestin2 and GRK6 actually play positive regulatory roles in mediating the chemotactic responses of T and B lymphocytes to CXCL12.L eukocytes migrate to sites of inflammation by recognizing a gradient of chemoattractants, and moving toward the chemoattractant source. This process of ligand recognition, cell polarization and directed cell migration is complex, given that a cell needs to integrate numerous signals arising from different spatial orientations to decide in which direction to move. In lymphocytes, the signals that guide the cell in making these decisions arise from chemokine activation of heptahelical G protein-coupled receptors (GPCR) linked to G␣i proteins. Directional migration, however, requires the activity of G␤␥, but not G␣, proteins (1, 2). In addition, Rho family guanosine triphosphatases (GTPases), the phosphoinositide 3-kinases, and possibly extracellular receptor kinases each play important roles in generating the cell polarity and cytoskeletal reorganization required for directional migration (3-7).Migration to chemokine gradients is dose dependent. Chemotaxis occurs at relatively low concentrations of chemokines, but at higher chemokine concentrations, cells become paralyzed and no longer migrate toward the chemoattractant source. The mechanisms by which cells are paralyzed at high chemokine concentrations are not clear but may involve agonist-dependent desensitization and receptor endocytosis mediated by G proteincoupled receptor kinases (GRKs) and arrestins. GRKs phosphorylate serine and threonine residues in the C terminus and intracellular loops of GPCRs, allowing for the association of arrestins that act to prevent heterotrimeric G␣␤␥ protein association with a...

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N-Formyl Peptide Receptor Ligation Induces Rac-dependent Actin Reorganization through Gβγ Subunits and Class Ia Phosphoinositide 3-Kinases

Cited by 25 publications

References 37 publications

Heterotrimeric G Protein βγ Subunits Stimulate FLJ00018, a Guanine Nucleotide Exchange Factor for Rac1 and Cdc42

Heterotrimeric G Protein βγ Subunits Stimulate FLJ00018, a Guanine Nucleotide Exchange Factor for Rac1 and Cdc42

Expression and Function of Formyl Peptide Receptors on Human Fibroblast Cells

Defective lymphocyte chemotaxis in β-arrestin2- and GRK6-deficient mice

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