Chemoattractant Receptor-G-Protein Coupling

Wenzel-Seifert, Katharina; Seifert, Roland

doi:10.1007/978-1-4614-7512-5_9

Cited by 11 publications

(17 citation statements)

References 226 publications

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“…2 (A, B, and E) and Tables I and III). A similar discrepancy between agonist affinity and agonist potency was reported for nonfused FPR expressed in HL-60 leukemia cells and Sf9 cells (25,26).…”

Section: Coupling Of the Formyl Peptide Receptor To G I Proteinssupporting

confidence: 73%

“…Thus, a substantial fraction of the FPRs appears to exist in a state of low agonist affinity that cannot be detected in the agonist binding assay but which, nonetheless, efficiently couples to G proteins to stimulate guanine nucleotide exchange. This model is supported by the fact that the EC 50 values of fMLF at activating GTP hydrolysis and guanine nucleotide binding to G i ␣ in fused and nonfused systems are ϳ100-fold higher than the K d values for [ 3 H]fMLF binding (12,13,25,26). Additionally, quantitative immunoblotting with anti-His 6 Ig and anti-FLAG Ig using ␤ 2 AR-G s ␣ L as standard demonstrated that agonist saturation binding greatly underestimates the actual expression level of FPR fusion proteins (Fig.…”

Section: Similarly Efficient Coupling Of the Fpr Tomentioning

confidence: 93%

“…Specifically, it is unclear why the K d value for high affinity [ 3 H]fMLF binding is ϳ3 nM, whereas the EC 50 value of fMLF at activating G i proteins in terms of GTP hydrolysis, AA-GTP labeling, and GTP␥S binding is much higher (ϳ0.1-1 M) (8,12,25,26). Similarly, it is unknown why fMLF is much more potent at activating chemotaxis than lysosomal enzyme release and superoxide radical formation (8, 19 -21).…”

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confidence: 99%

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Quantitative Analysis of Formyl Peptide Receptor Coupling to Giα1, Giα2, and Giα3

Wenzel-Seifert¹,

Arthur²,

Liu³

et al. 1999

Journal of Biological Chemistry

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Section: Coupling Of the Formyl Peptide Receptor To G I Proteinssupporting

confidence: 73%

Section: Similarly Efficient Coupling Of the Fpr Tomentioning

confidence: 93%

mentioning

confidence: 99%

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Quantitative Analysis of Formyl Peptide Receptor Coupling to Giα1, Giα2, and Giα3

Wenzel-Seifert¹,

Arthur²,

Liu³

et al. 1999

Journal of Biological Chemistry

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“…Neutrophils express GPCRs 1 for the chemoattractants fMLP, complement C5a, interleukin-8, leukotriene B 4 , and platelet-activating factor (3)(4)(5)(6). Chemoattractant receptors couple to G i proteins to activate phospholipase C␤2 and phosphoinositide 3-kinase-␥, with subsequent stimulation of chemotaxis, oxygen radical formation, and granule release (3,(7)(8)(9).…”

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confidence: 99%

Defective Gi Protein Coupling in Two Formyl Peptide Receptor Mutants Associated with Localized Juvenile Periodontitis

Seifert

Wenzel-Seifert

2001

Journal of Biological Chemistry

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Neutrophils play an important role in host defense against bacterial infections and in the pathogenesis of various inflammatory diseases (1, 2). Neutrophils express GPCRs 1 for the chemoattractants fMLP, complement C5a, interleukin-8, leukotriene B 4 , and platelet-activating factor (3-6). Chemoattractant receptors couple to G i proteins to activate phospholipase C␤2 and phosphoinositide 3-kinase-␥, with subsequent stimulation of chemotaxis, oxygen radical formation, and granule release (3, 7-9). Disruption of the FPR gene in mice increases susceptibility to infection by Listeria monocytogenes (10). However, although at cellular and molecular levels, the human FPR is one of the most extensively studied GPCRs (3-6, 8, 11), the in vivo role of the FPR in man has remained elusive.LJP is a defined periodontal disease that begins at ϳ11-15 years of age, affects the permanent incisors and/or first molars, and is associated with the presence of Actinobacillus actinomycetemcomitans in subgingival pockets. LJP is not associated with other diseases, and there is evidence that LJP is caused by a genetic defect (12, 13). It has been known for a long time that neutrophils from LJP patients show reduced binding of the agonist fMLP and reduced fMLP-induced chemotaxis (14 -16). Genetic analysis of 30 LJP patients revealed that 29 of those patients possess a F110S and/or C126W mutation in the FPR gene (17). In contrast, none of 31 patients with adult periodontitis and none of 20 control subjects possess a F110S or C126W mutation (17). The F110S mutation resides in the third transmembrane domain, whereas the C126W mutation resides in the second intracellular loop (Fig. 1). The second intracellular loop of the FPR is important for G i protein coupling (18), and a C126S mutation uncouples the FPR from G i proteins (19). Based on all these findings, we developed the hypothesis that the underlying cause of LJP is defective G i protein coupling of the FPR. To test this hypothesis, we engineered FLAG epitopetagged FPR-F110S and FPR-C126W and analyzed coupling of these FPR mutants and FPR-WT to the G protein G␣ i2 ␤ 1 ␥ 2 using Sf9 insect cells as the expression system. In previous studies, we already showed that Sf9 insect cells are a very sensitive system for studying G i protein coupling of chemoattractant receptors (20 -22). Here we report that FPR-F110S and FPR-C126W show an almost complete defect and a complete defect in G i protein coupling, respectively. The discrete clinical symptoms associated with the defective FPR indicate that the loss of FPR function in host defense is, for the most part, readily compensated. EXPERIMENTAL PROCEDURESMaterials-The baculovirus encoding G␣ i2 was kindly provided by Dr. A. G. Gilman (Department of Pharmacology, University of Southwestern Medical Center, Dallas, TX). Recombinant baculovirus encoding the unmodified versions of the G protein ␤ 1 ␥ 2 subunits was a kind gift of Dr.

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“…In differentiated cells, both basal and fMLP-stimulated PLC or PLD activity showed a significant increase, compared with undifferentiated cells. In addition, fMLP-induced PLC or PLD activation was significantly attenuated by pretreatment with CysH, a potent and selective FPR1 antagonist (25,26). Taken together, these data indicate that expression of functional FPR, particularly FPR1, is significantly increased during osteogenic differentiation of MSCs.…”

Section: H]inositol or [mentioning

confidence: 63%

N-Formyl-Methionyl-Leucyl-Phenylalanine (fMLP) Promotes Osteoblast Differentiation via the N-Formyl Peptide Receptor 1-mediated Signaling Pathway in Human Mesenchymal Stem Cells from Bone Marrow

Shin

Jang

Yoo

et al. 2011

Journal of Biological Chemistry

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Binding of N-formyl-methionyl-leucyl-phenylalanine (fMLP) to its specific cell surface receptor, N-formyl peptide receptor (FPR), triggers different cascades of biochemical events, eventually leading to cellular activation. However, the physiological role of fMLP and FPR during differentiation of mesenchymal stem cells is unknown. In this study, we attempted to determine whether fMLP regulates differentiation of mesenchymal stem cells derived from bone marrow. Analysis by quantitative-PCR and flow cytometry showed significantly increased expression of FPR1, but not FPR2 and FPR3, during osteoblastic differentiation. fMLP, a specific ligand of FPR1, promotes osteoblastic commitment and suppresses adipogenic commitment under differentiation conditions. Remarkably, fMLP-stimulated osteogenesis is associated with increased expression of osteogenic markers and mineralization, which were blocked by cyclosporine H, a selective FPR1 antagonist. In addition, fMLP inhibited expression of peroxisome proliferator-activated receptor-␥1, a major regulator of adipocytic differentiation. fMLP-stimulated osteogenic differentiation was mediated via FPR1-phospholipase C/phospholipase D-Ca 2؉ -calmodulin-dependent kinase II-ERK-CREB signaling pathways. Finally, fMLP promoted bone formation in zebrafish and rabbits, suggesting its physiological relevance in vivo. Collectively, our findings provide novel insight into the functional role of fMLP in bone biology, with important implications for its potential use as a therapeutic agent for treatment of bone-related disorders.

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Chemoattractant Receptor-G-Protein Coupling

Cited by 11 publications

References 226 publications

Quantitative Analysis of Formyl Peptide Receptor Coupling to Giα1, Giα2, and Giα3

Quantitative Analysis of Formyl Peptide Receptor Coupling to Giα1, Giα2, and Giα3

Defective Gi Protein Coupling in Two Formyl Peptide Receptor Mutants Associated with Localized Juvenile Periodontitis

N-Formyl-Methionyl-Leucyl-Phenylalanine (fMLP) Promotes Osteoblast Differentiation via the N-Formyl Peptide Receptor 1-mediated Signaling Pathway in Human Mesenchymal Stem Cells from Bone Marrow

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