The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)

Significance of the extracellular domain and the carbohydrates of the human neutrophil N-formyl peptide chemotactic receptor for the signal transduction by the receptor.

The N-formyl peptide chemotactic receptor of human neutrophils possesses a 2-kDa papain-removable extracellular domain that contains two N-linked oligosaccharide side chains and is not required for the high-affinity ligand binding. In the present study, the significance of the extracellular domain and the carbohydrates for signal transduction was elucidated by measuring the N-formyl hexapeptide-induced intracellular free calcium ([Ca2+]i) and the change in myeloperoxidase secretion in the control and papain-treated human neutrophils. [Ca2+]i was monitored both in cell suspension and individual cells with intracellularly trapped Fura 2 acetoxymethyl ester, using spectrofluorometric analysis and fluorescence ratio image analysis, respectively. The exposure of the cells in suspension to N-formyl hexapeptide resulted in an immediate, dose-dependent burst of elevated [Ca2+]i, which was virtually identical in both control and papain-treated cells with respect to the extent and kinetics. The maximum burst was 1.6-fold and was obtained at 10(-6) M hexapeptide. The individual control and papain-treated cells responded to 10(-6) M hexapeptide in a similar manner with several successive transients of [Ca2+]i, the maximum level being 3.0-3.5 microM. In both groups the [Ca2+]i transient began initially in the cell periphery, expanding rapidly throughout the cells. Concomitantly, the cells became polarized, and their chemokinesis increased. The secretion of myeloperoxidase was monitored as a physiological end response to N-formyl chemotactic peptides. The exposure of the control and papain-treated cells in suspension to hexapeptide resulted in a dose-dependent secretion of myeloperoxidase. The maximum secretion after exposure to 10(-8)-10(-6) M hexapeptide was equal in control and papain-treated neutrophils. These results indicate that the functional properties of the membrane-inserted N-formyl peptide chemotactic receptor are inherent to the receptor's transmembrane and intracellular domains, as far as binding of the ligand and subsequent receptor activation are concerned.[1]


WikiGenes - Universities