Neutrophil cytosol

Eklund, E. A., Marshall, M Gibbs, J. B Crean, C. D Gabig, T. G. (1991). Resolution of a low molecular weight G protein in neutrophil cytosol required for NADPH oxidase activation and reconstitution by recombinant Krev-1 protein. J. Biol. Chem. 266, 13964-70. 

Cumutte, J. T., Scott, P. J., Babior, B. M. (1989). Functional defect in neutrophil cytosols from two patients with autosomal recessive cytochrome-positive chronic granulomatous disease. J. Clin. Invest. 83, 1236-40. 

Nunoi, H., Rotrosen, D., Gallin, J. I., Malech, H. L. (1988). Two forms of autosomal chronic granulomatous disease lack distinct neutrophil cytosol factors. Science 242, 1298-1301. 

Enzyme preparations obtained from rat neutrophil cytosol were inhibited very slightly by cycloheterophyllin, whereas those obtained from rat brain were moderately dose-dependently inhibited by the same compound at doses between 6 and 60 oM. Some degree of competition... 

Bourmeyster N, Stasia M-J, Garin J et al. (1992) Copurification of rho protein and the rho-GDP dissociation inhibitor from bovine neutrophil cytosol. Effect of phosphoinosifides on rho ADP-ribosylafion by the C3 exoenzyme of Clostridium botulinum. In Biochemistry 31 12863-9... 

First, an overlay assay was used to demonstrate binding of photoaffinity labeled FPR to actin from neutrophil cytosol [49]. Second, actin increased the sedimentation rate of Triton X-lOO-solubilized FPR in a sucrose density gradient [49]. Third, anti-actin antibodies were able to immunosediment FPR suggesting... 

Figure 1. Simplified schematic of receptor-mediated signal transduction in neutrophils. Binding of ligand to the receptor activates a guanine-nucleotide-binding protein (G protein), which then stimulates phospholipase C. Phosphatidylinositol 4,5-bis-phosphate is cleaved to produce diacylglycerol (DAG) and inositol 1,4,5-trisphosphate (IP3). DAG stimulates protein kinase C. IP3 causes the release of Ca from intracellular stores, which results in an increase in the cytosolic Ca concentration. This increase in Ca may stimulate protein kinase C, calmodulin-dependent protein kinases, and phospholipase A2. Protein phosphorylation events are thought to be important in stimulating degranulation and oxidant production. In addition, ionic fluxes occur across the plasma membrane. It is possible that phospholipase A2 and ionic channels may be governed by G protein interactions. ...

Figure 7. Neutrophil degranulation (A) and lndo-1-detected cytosolic Ca responses (B) in the presence of cytochalasin B. Cells were labeled with lndo-1, degranulation was measured as...

Neutrophils represent an ideal system for studying osmotic effects on exocytosis. Stimulation of cytochalasin-B-treated neutrophils with the chemotactic peptide Jlf-formylmethionyl-leucyl-phenyl-alanine (FMLP) results in a rapid compound exocytosis up to 80% of lysosomal enzymes are released within 30 s (9-14). Secretion appears to be triggered by a rise in the level of cytosolic free calcium (15-18) promoted in part by entry of extracellular calcium through receptor-gated channels and in part by release of calcium that is sequestered or bound at some intracellular site (19-21). In this presentation, we augment our previously published data (22,23), which demonstrates that lysosomal enzyme release from neutrophils is inhibited under hyperosmotic conditions and that the rise in cytosolic calcium preceding secretion is inhibited as well. 

Kanerud, L., Hafttrom, 1. and Ringertz, B. (1990). Effect of sulphasalazine and sulphapyridine on neutrophil superoxide production role of cytosolic free calcium. Ann. Rheum. Dis. 49, 296-300. 

NO is a gaseous neurotransmitter implicated in signaling in the central and peripheral nervous system as well as in the immune system and the vasculature. NO is formed from L-arginine by nitric oxide synthase (NOS). There are three isoforms of NOS. All isoforms require NADPH as a cofactor, use L-arginine as a substrate, and are inhibited by Nw-nitro-L-arginine methyl ester (L-NAME). The three isoforms are separate gene products. One isoform of NOS is a cytosolic, calcium/calmodulin-independent, inducible enzyme (iNOS). It is found in macrophages, neutrophils, vascular smooth muscle, and endothelia. The iNOS... 

These effects of ATP are blocked by pertussis toxin, and so the putative ATP receptor is G-protein linked. ATP addition results in phospholipase C activation, which may be detected as increased inositol phosphate metabolism and subsequent elevations in cytosolic free Ca2+. Purinergic receptors on many types of cells are classified as type Pi or P2. Neutrophils possess P2-type receptors, which are activated by ATP and ADP, and also Pi-type receptors, which are activated by adenosine. Occupancy of P2-type receptors enhances fMet-Leu-Phe-mediated effects, whilst occupancy of Pi-type receptors has the opposing effect. Some pharmacological evidence suggests that the P2-type receptor on neutrophils is distinct from the P2X and P2y subtypes that have been described in other cell types. 

Knaus, U. G., Heyworth, P. G., Kinsella, T., Cumutte, J. T., Bokoch, G. M. (1992). Purification and characterisation of Rac2. A cytosolic GTP-binding protein that regulates human neutrophil NADPH oxidase. J. Biol. Chem. 267, 23575-82. 

Nakanishi, A., Imajoh-Ohmi, S., Fujinawa, T., Kikuchi, H., Kanegasaki, S. (1992). Direct evidence for interaction between COOH-terminal regions of cytochrome bssg subunits and cytosolic 47-kDa protein during activation of an 02"-generating system in neutrophils. J. Biol. Chem. 267, 19072-4. 

Volpp, B. D., Nauseef, W. M Donelson, J. E Moser, D. R Clark, R. A. (1989). Cloning of the cDNA and functional expression of the 47-kilodalton cytosolic component of human respiratory burst oxidase. Proc. Natl. Acad. Sci. USA 86, 7195-9. Watson, F., Robinson, J. J., Edwards, S. W. (1991). Protein kinase C dependent and independent activation of the NADPH oxidase of human neutrophils. J. Biol. Chem. 266, 7432-9. 

Gabig, T. G., Eklund, E. A., Potter, G. B., Dykes, J. R., II (1990). A neutrophil GTP-binding protein that regulates cellfree NADPH oxidase activation is located in the cytosolic fraction. J. Immunol. 145,945-51. 

Kessels, G. C. R., Roos, D., Verhoeven, A. J. (1991). fMet-Leu-Phe-induced activation of phospholipase D in human neutrophils. Dependence on changes in cytosolic free... 

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