title: GTP-binding proteins in polymorphonuclear granulocytes of severely burned patients.
abstract: In order to study the biochemical mechanism underlying the cellular dysfunctions of polymorphonuclear granulocytes (PMNs) from severely burned patients, we analyzed the role of GTP-binding proteins (G-proteins) in PMNs from 11 burned patients. Our data demonstrate a significant enhancement of the basal GTPase activity within unstimulated neutrophils of severely burned patients compared to cells from healthy donors. This enhancement was significant within 4 weeks after the trauma, followed by a return to control levels. The increase in GTPase activity correlated with enhanced expression of the small G-protein Ras and the regulatory Ras-GTPase activating protein (Ras-GAP) compared to that in healthy donor cells. However, expression of the Ras-related protein Rap1, which is involved in initiation of the respiratory burst, was reduced. The observed changes in G-protein activity and expression impair the signal transduction cascade as well as bacterial killing and may lead to high susceptibility toward infections and finally to septic conditions.
authors.affiliation: Lehstuhl für Medizinische Mikrobiologie und Immunologie, Arbeitsgruppe Infektabwehrmechanismen, Ruhr-Universität Bochum, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Brom
authors.forename: M
authors.initials: M
authors.lastname: Köller
authors.forename: P
authors.initials: P
authors.lastname: Müller-Lange
authors.forename: H U
authors.initials: HU
authors.lastname: Steinau
authors.forename: W
authors.initials: W
authors.lastname: König
mesh_terms: D000328:Adult; D001345:Autoradiography; D002056:Burns / Q000097:blood* / Q000473:pathology; D005260:Female; D020558:GTP Phosphohydrolases / Q000097:blood; D019204:GTP-Binding Proteins / Q000032:analysis*; D020690:GTPase-Activating Proteins; D006801:Humans; D015151:Immunoblotting; D008297:Male; D008861:Microsomes / Q000201:enzymology; D008875:Middle Aged; D009504:Neutrophils / Q000737:chemistry* / Q000502:physiology; D011506:Proteins / Q000032:analysis; D020703:ras GTPase-Activating Proteins
chemical_list: D020690:GTPase-Activating Proteins; D011506:Proteins; D020703:ras GTPase-Activating Proteins; D020558:GTP Phosphohydrolases; D019204:GTP-Binding Proteins