Complement fragment (C)5a is a 74 residue pro-inflammatory polypeptide produced during activation of the complement cascade of serum proteins in response to foreign surfaces such as microorganisms and tissue damaged by physical or chemical injury. C5a binds to at least two seven-transmembrane domain receptors, C5aR (C5R1, CD88) and C5L2 (gpr77), expressed ubiquitously on a wide variety of cells but particularly on the surface of immune cells like macrophages, neutrophils and T cells. C5aR is a classical G protein-coupled receptor that signals through G alpha i and G alpha 16, whereas C5L2 does not appear to couple to G proteins and has no known signalling activity. Although C5a was first described as an anaphylatoxin and later as a leukocyte chemoattractant, the widespread expression of C5aR suggested more general functionality. Our understanding of the physiology of C5a has improved significantly in recent years through exploitation of receptor knockout and knocking mice, C5 and C5a antibodies, soluble recombinant C5a and C5a analogues and newly developed receptor antagonists. C5a is now also implicated in non-immunological functions associated with developmental biology, CNS development and neurodegeneration, tissue regenerat...Continue Reading
Quantification of mouse macrophage chemotaxis in vitro: role of C5 for the production of chemotactic activity.
The regulation of actin polymerization in differentiating U937 cells correlates with increased membrane levels of the pertussis-toxin-sensitive G-protein Gi2
Tertiary structure of human complement component C5a in solution from nuclear magnetic resonance data
Potential role of activated macrophages in acetaminophen hepatotoxicity. I. Isolation and characterization of activated macrophages from rat liver
C5a decreases regional coronary blood flow and myocardial function in pigs: implications for a granulocyte mechanism
Complement activation in cystic fibrosis respiratory fluids: in vivo and in vitro generation of C5a and chemotactic activity
The lectin leucoagglutinin binds specifically to human granulocytes, monocytes and tissue mast cells: further evidence for a common origin of the three cell types
Involvement of complement in psoriasis and atopic dermatitis--measurement of C3a and C5a, C3, C4 and C1 inactivator
The relationship of the chemotactic behavior of the complement-derived factors, C3a, C5a, and C567, and a bacterial chemotactic factor to their ability to activate the proesterase 1 of rabbit polymorphonuclear leukocytes
Association of complement activation and elevated plasma-C5a with adult respiratory distress syndrome. Pathophysiological relevance and possible prognostic value
Human monocyte chemotaxis: migrating cells are a subpopulation with multiple chemotaxin specificities on each cell.
N-formylpeptide and complement C5a receptors are expressed in liver cells and mediate hepatic acute phase gene regulation
Mutation of glutamate 199 of the human C5a receptor defines a binding site for ligand distinct from the receptor N terminus.
Probing the "message:address" sites for chemoattractant binding to the C5a receptor. Mutagenesis of hydrophilic and proline residues within the transmembrane segments.
Anti-inflammatory effects and specificity of L-156,602: comparison of effects on concanavalin A and zymosan-induced footpad edema, and contact sensitivity response
Mutation of aspartate 82 of the human C5a receptor abolishes the secretory response to human C5a in transfected rat basophilic leukemia cells
Generation of chimeric C5a/formyl peptide receptors: towards the identification of the human C5a receptor binding site
Site-specific mutagenesis of residues in the human C5a anaphylatoxin which are involved in possible interaction with the C5a receptor
Characterization of a complement-fragment-C5a-stimulated calcium-influx mechanism in U937 monocytic cells
Evidence that the extracellular N-terminal domain of C5aR contains amino-acid residues crucial for C5a binding
Human chemotaxis receptor genes cluster at 19q13.3-13.4. Characterization of the human C5a receptor gene
Synthetic C5a receptor agonists. Pharmacology, metabolism and in vivo cardiovascular and hematologic effects
Monocyte chemotactic factor in rheumatoid arthritis synovial tissue. Probably a cross-linked derivative of S19 ribosomal protein.
Ultrafiltration after cardiopulmonary bypass in children: effects on hemodynamics, cytokines and complement
Biologically active conformer of the effector region of human C5a and modulatory effects of N-terminal receptor binding determinants on activity
Role of phospholipase Cbeta3 phosphorylation in the desensitization of cellular responses to platelet-activating factor.
Chemoattractant receptors for interleukin-8 and C5a: expression on peripheral blood leukocytes and differential regulation on HL-60 and AML-193 cells by vitamin D3 and all-trans retinoic acid
Structural definition of the C5a C terminus by two-dimensional nuclear magnetic resonance spectroscopy
The C terminus of the human C5a receptor (CD88) is required for normal ligand-dependent receptor internalization
Impaired inflammatory responses in the reverse arthus reaction through genetic deletion of the C5a receptor
The role of the ribosomal protein S19 C-terminus in Gi protein-dependent alternative activation of p38 MAP kinase via the C5a receptor in HMC-1 cells
C5a, but not C5a-des Arg, induces upregulation of heteromer formation between complement C5a receptors C5aR and C5L2
Phosphoinositide 3-kinases gamma and delta, linkers of coordinate C5a receptor-Fcgamma receptor activation and immune complex-induced inflammation
Structure of the tyrosine-sulfated C5a receptor N terminus in complex with chemotaxis inhibitory protein of Staphylococcus aureus
Retrieving novel C5aR antagonists using a hybrid ligand-based virtual screening protocol based on SVM classification and pharmacophore models
The role of the ribosomal protein S19 C-terminus in altering the chemotaxis of leucocytes by causing functional differences in the C5a receptor response
Elimination of C5aR prevents intestinal mucosal damage and attenuates neutrophil infiltration in local and remote organs
Microarray analysis of irradiated growth plate zones following laser microdissection shows later importance of differentially expressed genes during radiorecovery
Molecular mechanisms of inflammation and tissue injury after major trauma--is complement the "bad guy"?
Complement activation fragment C5a receptors, CD88 and C5L2, are associated with neurofibrillary pathology
The C5a anaphylatoxin receptor CD88 is expressed in presynaptic terminals of hippocampal mossy fibres
Blurred line between chemotactic chase and phagocytic consumption: an immunophysical single-cell perspective
C5a enhances dysregulated inflammatory and angiogenic responses to malaria in vitro: potential implications for placental malaria
A recombinant vaccine effectively induces c5a-specific neutralizing antibodies and prevents arthritis
The global effect of follicle-stimulating hormone and tumour necrosis factor α on gene expression in cultured bovine ovarian granulosa cells
Protein kinase C-δ mediates sepsis-induced activation of complement 5a and urokinase-type plasminogen activator signaling in macrophages
A peptide mimic of the chemotaxis inhibitory protein of Staphylococcus aureus: towards the development of novel anti-inflammatory compounds.
C5a2 can modulate ERK1/2 signaling in macrophages via heteromer formation with C5a1 and β-arrestin recruitment
Anaphylatoxin receptors and complement regulatory proteins in human articular and non-articular chondrocytes: interrelation with cytokines
Dual functions of the C5a receptor as a connector for the K562 erythroblast-like cell-THP-1 macrophage-like cell island and as a sensor for the differentiation of the K562 erythroblast-like cell during haemin-induced erythropoiesis
The staphylococcal toxins γ-haemolysin AB and CB differentially target phagocytes by employing specific chemokine receptors
Leucocyte expression of complement C5a receptors exacerbates infarct size after myocardial reperfusion injury
C5a receptor (CD88) inhibition improves hypothermia-induced neuroprotection in an in vitro ischemic model
Anaphylaxis is a serious allergic reaction that is rapid in onset and may cause death.
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