Biomaterial Database

Receptors and intracellular signaling in human neutrophils. 1990

P D Lew

Infectious Diseases Division, Geneva University Hospital, Switzerland.

Adherence, chemotaxis, phagocytosis, and responses to cytokines are mediated by distinct classes of cell surface receptors in human neutrophils. Intracellular signaling by these different receptors is a subject of active investigation. Observation of single neutrophils adherent to surfaces reveals the presence of spontaneous oscillations of cytosolic-free calcium, [Ca2+]i, generated by mechanisms that are presently unknown. Chemoattractant receptor activation via a specific G-regulatory protein activates a plasma membrane phospholipase C and generates diacylglycerol and inositol(1,4,5)triphosphate. DG activates C kinase(s). Ins(1,4,5)P3 releases Ca2+ from a specific intracellular organelle, the calciosome. Calciosomes resemble sarcoplasmic reticulum: they contain a Ca2(+)-ATPase and a high capacity/low affinity calcium-binding, calsequestrin-like protein. Chemoattractant receptor stimulation of calcium influx across the plasma membrane in phagocytes correlates strongly with the conversion of Ins(1,3,4,5)P3 to Ins(1,3,4,5)P4 by a Ca2(+)-calmodulin-sensitive kinase. The transduction system of phagocytosis receptors also generates DG and Ins(1,4,5)P3 and elicits [Ca2+]i elevations. The Ca2+ signal is an important regulator of secretion (granule exocytosis, superoxide production), whereas C kinase(s)/and other unknown mediators appear to be more important for the control of movement. Several mechanisms that could account for the specificity of cell signaling by different receptors are discussed.

UI	MeSH Term	Description	Entries
D009504	Neutrophils	Granular leukocytes having a nucleus with three to five lobes connected by slender threads of chromatin, and cytoplasm containing fine inconspicuous granules and stainable by neutral dyes.	LE Cells,Leukocytes, Polymorphonuclear,Polymorphonuclear Leukocytes,Polymorphonuclear Neutrophils,Neutrophil Band Cells,Band Cell, Neutrophil,Cell, LE,LE Cell,Leukocyte, Polymorphonuclear,Neutrophil,Neutrophil Band Cell,Neutrophil, Polymorphonuclear,Polymorphonuclear Leukocyte,Polymorphonuclear Neutrophil
D011493	Protein Kinase C	An serine-threonine protein kinase that requires the presence of physiological concentrations of CALCIUM and membrane PHOSPHOLIPIDS. The additional presence of DIACYLGLYCEROLS markedly increases its sensitivity to both calcium and phospholipids. The sensitivity of the enzyme can also be increased by PHORBOL ESTERS and it is believed that protein kinase C is the receptor protein of tumor-promoting phorbol esters.	Calcium Phospholipid-Dependent Protein Kinase,Calcium-Activated Phospholipid-Dependent Kinase,PKC Serine-Threonine Kinase,Phospholipid-Sensitive Calcium-Dependent Protein Kinase,Protein Kinase M,Calcium Activated Phospholipid Dependent Kinase,Calcium Phospholipid Dependent Protein Kinase,PKC Serine Threonine Kinase,Phospholipid Sensitive Calcium Dependent Protein Kinase,Phospholipid-Dependent Kinase, Calcium-Activated,Serine-Threonine Kinase, PKC
D011971	Receptors, Immunologic	Cell surface molecules on cells of the immune system that specifically bind surface molecules or messenger molecules and trigger changes in the behavior of cells. Although these receptors were first identified in the immune system, many have important functions elsewhere.	Immunologic Receptors,Immunologic Receptor,Immunological Receptors,Receptor, Immunologic,Receptors, Immunological
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D015398	Signal Transduction	The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.	Cell Signaling,Receptor-Mediated Signal Transduction,Signal Pathways,Receptor Mediated Signal Transduction,Signal Transduction Pathways,Signal Transduction Systems,Pathway, Signal,Pathway, Signal Transduction,Pathways, Signal,Pathways, Signal Transduction,Receptor-Mediated Signal Transductions,Signal Pathway,Signal Transduction Pathway,Signal Transduction System,Signal Transduction, Receptor-Mediated,Signal Transductions,Signal Transductions, Receptor-Mediated,System, Signal Transduction,Systems, Signal Transduction,Transduction, Signal,Transductions, Signal
D015815	Cell Adhesion Molecules	Surface ligands, usually glycoproteins, that mediate cell-to-cell adhesion. Their functions include the assembly and interconnection of various vertebrate systems, as well as maintenance of tissue integration, wound healing, morphogenic movements, cellular migrations, and metastasis.	Cell Adhesion Molecule,Intercellular Adhesion Molecule,Intercellular Adhesion Molecules,Leukocyte Adhesion Molecule,Leukocyte Adhesion Molecules,Saccharide-Mediated Cell Adhesion Molecules,Saccharide Mediated Cell Adhesion Molecules,Adhesion Molecule, Cell,Adhesion Molecule, Intercellular,Adhesion Molecule, Leukocyte,Adhesion Molecules, Cell,Adhesion Molecules, Intercellular,Adhesion Molecules, Leukocyte,Molecule, Cell Adhesion,Molecule, Intercellular Adhesion,Molecule, Leukocyte Adhesion,Molecules, Cell Adhesion,Molecules, Intercellular Adhesion,Molecules, Leukocyte Adhesion
D044042	Receptors, Formyl Peptide	A family of G-protein-coupled receptors that was originally identified by its ability to bind N-formyl peptides such as N-FORMYLMETHIONINE LEUCYL-PHENYLALANINE. Since N-formyl peptides are found in MITOCHONDRIA and BACTERIA, this class of receptors is believed to play a role in mediating cellular responses to cellular damage and bacterial invasion. However, non-formylated peptide ligands have also been found for this receptor class.	Chemotactic Peptide Receptor,Chemoattractant Receptor,F-Chemotactic Peptide Receptor,FMLP Receptor,Formyl Peptide Receptor,N-Formylmethionyl Peptide Receptor,N-formyl Hexapeptide Receptor,Receptor, Chemotactic Peptide,fMet-Leu-Phe Receptor,F Chemotactic Peptide Receptor,Formyl Peptide Receptors,Hexapeptide Receptor, N-formyl,N Formylmethionyl Peptide Receptor,N formyl Hexapeptide Receptor,Peptide Receptor, Chemotactic,Peptide Receptor, N-Formylmethionyl,Peptide Receptors, Formyl,Receptor, Chemoattractant,Receptor, F-Chemotactic Peptide,Receptor, FMLP,Receptor, Formyl Peptide,Receptor, N-Formylmethionyl Peptide,Receptor, N-formyl Hexapeptide,Receptor, fMet-Leu-Phe,fMet Leu Phe Receptor