Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0043167 (pertussis)
 19,595 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To investigate the ability of FcgammaRIII(PMN), the GPI-anchored isoform of FcgammaRIII (CD16) in polymorphonuclear leukocytes (PMN), to mediate transmembrane signaling events, we measured changes in membrane potential with DiOC(5) and in intracellular calcium with indo-1. FcgammaR were ligated by anti-FcgammaRIII mAb 3G8 (IgG and Fab), anti-FcgammaRII mAb IV.3 (IgG and Fab), and human IgG aggregates. Cell bound mAbs were also crosslinked by goat F(ab')(2) anti-mouse IgG. 3G8 IgG elicited a rapid change in [Ca(2+)](i), which was unaffected by EGTA, Vibrio cholerae toxin (CT), or Bordetella pertussis toxin (PT), and was abolished by BAPTA . Univalent receptor binding with 3G8 Fab gave no response but crosslinking with F(aV)2 GAM gave a rapid [Ca2,](i) response. Neither IV.3 Fab, IV.3 IgG, nor crosslinking of IV.3 Fab elicited a calcium signal. PI-PLC-treated PMN with the density of FcgammaRIII(PMN) reduced to that of FcgammaRII showed an unattenuated change in [Ca(2+)](i), with a 3G8 stimulus. The effects of IgG aggregates paralleled those of 3G8 mAb. These data indicate that multivalent ligation of FcgammaRIII(PMN) initiates an increase in [Ca(2+)];, derived from intracellular stores, that is distinct from both the FMLP- and FcgammaRII-induced responses. Ligand-dependent interaction with FcgammaRII is not required. Since FcgammaRIII(PMN) can internalize the FcgammaRIII-specific probe Con A-opsonized E and lyse anti-FcgammaRIII heteroantibody-opsonized chick E, this GPI-anchored molecule mediates both signal transduction and integrated cell responses.
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PMID:The glycosyl phosphatidylinositol-linked Fc gamma RIIIPMN mediates transmembrane signaling events distinct from Fc gamma RII. 213 1

GPI-linked protein molecules become Triton-insoluble during polarized sorting to the apical cell surface of epithelial cells. These insoluble complexes, enriched in cholesterol, glycolipids, and GPI-linked proteins, have been isolated by flotation on sucrose density gradients and are thought to contain the putative GPI-sorting machinery. As the cellular origin and molecular protein components of this complex remain unknown, we have begun to characterize these low-density insoluble complexes isolated from MDCK cells. We find that these complexes, which represent 0.4-0.8% of the plasma membrane, ultrastructurally resemble caveolae and are over 150-fold enriched in a model GPI-anchored protein and caveolin, a caveolar marker protein. However, they exclude many other plasma membrane associated molecules and organelle-specific marker enzymes, suggesting that they represent microdomains of the plasma membrane. In addition to caveolin, these insoluble complexes contain a subset of hydrophobic plasma membrane proteins and cytoplasmically-oriented signaling molecules, including: (a) GTP-binding proteins--both small and heterotrimeric; (b) annex II--an apical calcium-regulated phospholipid binding protein with a demonstrated role in exocytic fusion events; (c) c-Yes--an apically localized member of the Src family of non-receptor type protein-tyrosine kinases; and (d) an unidentified serine-kinase activity. As we demonstrate that caveolin is both a transmembrane molecule and a major phospho-acceptor component of these complexes, we propose that caveolin could function as a transmembrane adaptor molecule that couples luminal GPI-linked proteins with cytoplasmically oriented signaling molecules during GPI-membrane trafficking or GPI-mediated signal transduction events. In addition, our results have implications for understanding v-Src transformation and the actions of cholera and pertussis toxins on hetero-trimeric G proteins.
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PMID:Signal transducing molecules and glycosyl-phosphatidylinositol-linked proteins form a caveolin-rich insoluble complex in MDCK cells. 834 30

The RT6 T cell mono(ADP-ribosyl)transferases are expressed as GPI-anchored membrane proteins by mature T lymphocytes. We performed secondary structure prediction analyses of RT6 with a profile based neural network system based on multiple alignments of RT6 with other vertebrate mono(ADP-ribosyl)transferases (mADPRTs). The results reveal a linear order of predicted beta sheets/alpha helix in RT6 that are quite similar to those in the catalytic subunit of the four known crystal structures of mono-ADP-ribosylating bacterial toxins. Recognizable amino acid similarities occur throughout the region of predicted structural homology to the bacterial toxins. Three residues which have been shown to be important for catalysis in bacterial toxins (e.g. R9, S52 and E129 in pertussis toxin) occur in a similar context also in RT6 (R126, S147 and E189). We have mutated these residues in RT6 by site-directed mutagenesis. The RT6 mutants exhibit remarkably similar alterations in enzymatic phenotype as those reported for mutations of the proposed analagous residues in bacterial toxins. These results support the hypothesis that eu- and procaryotic mADPRTs share a common fold and have a common ancestry.
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PMID:Using secondary structure predictions and site-directed mutagenesis to identify and probe the role of potential active site motifs in the RT6 mono(ADP-ribosyl)transferases. 919 53

The glycosyl-phosphatidylinositol anchored protein, membrane dipeptidase (EC 3.4.13.19) is released from the surface of 3T3-L1 adipocytes in response to insulin treatment through the action of a phospholipase C. The present study investigates the role of guanine-nucleotide binding proteins (G-proteins) in this process. Treatment of permeabilized 3T3-L1 adipocytes with GTPgammaS did not cause release of membrane dipeptidase into the medium, while GDPbetaS did not inhibit the insulin-stimulated release of membrane dipeptidase. Other activators of G-proteins, including the tetradecapeptide mastoparan, pertussis toxin and AlF3, also caused no significant release of membrane dipeptidase from the surface of the 3T3-L1 adipocytes. From these observations it is concluded that G-proteins are not involved in the insulin-stimulated release of membrane dipeptidase. Although X-Pro aminopeptidase (EC 3.4.11.9) is GPI-anchored in 3T3-L1 adipocytes as shown by digestion with bacterial phosphatidylinositol-specific phospholipase C, it was not released upon insulin treatment of the cells, indicating that only a subset of the GPI-anchored proteins are susceptible to insulin-stimulated release.
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PMID:Insulin stimulates the release of a subset of GPI-anchored proteins in a G-protein independent manner. 1082 37

Spatially restricted activation of signaling molecules governs critical aspects of cell migration; the mechanism by which this is achieved nonetheless remains unknown. Using time-lapse confocal microscopy, we analyzed dynamic redistribution of lipid rafts in chemoattractant-stimulated leukocytes expressing glycosyl phosphatidylinositol-anchored green fluorescent protein (GFP-GPI). Chemoattractants induced persistent GFP-GPI redistribution to the leading edge raft (L raft) and uropod rafts of Jurkat, HL60, and dimethyl sulfoxide-differentiated HL60 cells in a pertussis toxin-sensitive, actin-dependent manner. A transmembrane, nonraft GFP protein was distributed homogeneously in moving cells. A GFP-CCR5 chimera, which partitions in L rafts, accumulated at the leading edge, and CCR5 redistribution coincided with recruitment and activation of phosphatidylinositol-3 kinase gamma in L rafts in polarized, moving cells. Membrane cholesterol depletion impeded raft redistribution and asymmetric recruitment of PI3K to the cell side facing the chemoattractant source. This is the first direct evidence that lipid rafts order spatial signaling in moving mammalian cells, by concentrating the gradient sensing machinery at the leading edge.
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PMID:Dynamic redistribution of raft domains as an organizing platform for signaling during cell chemotaxis. 1498 Oct 96

IgLONs are a family of four GPI-anchored cell adhesion molecules that regulate neurite outgrowth, synaptogenesis and may act as tumour suppressor genes. IgLONs are thought to function as monomers or homodimers and we have proposed that IgLONs also act as heterodimeric complexes termed Dimeric IgLONs or DIgLONs. Here we show that the initiation of neurite outgrowth is inhibited from a subset of chick embryonic day (E) 7 or 8 forebrain neurons when they are cultured on CHO cell lines expressing DIgLON:CEPU-1-OBCAM and DIgLON:CEPU-1-LAMP but not on CHO cells that express single IgLONs CEPU-1 or OBCAM. Surprisingly at the younger age of E6 forebrain neurons do not respond to DIgLONs. Since there is little difference in expression of IgLONs on the surface of chick forebrain neurons at these two ages we suggest IgLONs alone are not the receptor on the responding forebrain neurons. A DIgLON heterodimeric recombinant protein DIgLON:CEPU-1-OBCAM-Fc also blocked neurite outgrowth from E8 chick forebrain neurons. However, when IgLONs were removed from the surface of these E8 neurons they no longer responded to DIgLON:CEPU-1-OBCAM-Fc substrate, indicating that IgLONs form at least a component of the neuronal cell receptor complex involved in this inhibition of neurite outgrowth. Inhibitors pertussis toxin and Y27632 reversed the inhibition of neurite outgrowth on a DIgLON:CEPU-1-OBCAM and DIgLON:CEPU-1-LAMP substrate. This suggests the involvement of a G-protein coupled receptor and activation of Rho A. In summary we provide evidence that DIgLON:CEPU-1-OBCAM and DIgLON:CEPU-1-LAMP complexes regulate initiation of neurite outgrowth on forebrain neurons via an IgLON-containing receptor complex.
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PMID:DIgLONs inhibit initiation of neurite outgrowth from forebrain neurons via an IgLON-containing receptor complex. 2116 20

It has been recognized that pertussis is a disease that affects all age groups. There are obvious limitations in the currently used diagnostic criteria with "one-size-fits-all" definition, which is not advantageous to start individual treatment and perform strategies for preventing the transmission. Therefore, the expert group of Global Pertussis Initiative gives a suggestion for the diagnosis of pertussis. Based on the related published studies, the present article analyzes the limitations of the current criteria, and introduces the GPI's suggestion in detail.
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PMID:[Pertussis diagnosis: the limitation of the currently used criteria and the suggestion of Global Pertussis Initiative]. 2765 50