Linked Life Data

11513579

Source:http://linkedlifedata.com/resource/pubmed/id/11513579

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
34
pubmed:dateCreated
2001-8-21
pubmed:abstractText
The low molecular weight GTP binding protein Rac is essential to the activation of the NADPH oxidase complex, involved in pathogen killing during phagocytosis. In resting cells, Rac exists as a heterodimeric complex with Rho GDP dissociation inhibitor (Rho-GDI). Two types of interactions exist between Rac and Rho-GDI: a protein-lipid interaction, implicating the polyisoprene of the GTPase, as well as protein-protein interactions. Using the two-hybrid system, we show that nonprenylated Rac1 interacts very weakly with Rho-GDI, pointing to the predominant role of protein-isoprene interaction in complex formation. In the absence of this strong interaction, we demonstrate that three sites of protein-protein interaction, Arg66(Rac)-Leu67(Rac), His103(Rac), and the C-terminal polybasic region Arg183(Rac)-Lys188(Rac), are involved and cooperate in complex formation. When Rac1 mutants are prenylated by expression in insect cells, they all interact with Rho-GDI. Rho-GDI is able to exert an inhibitory effect on the GDP/GTP exchange reaction except in the complex in which Rac1 has a deletion of the polybasic region (Arg183(Rac)-Lys188(Rac)). This complex is, most likely, held together through protein-lipid interaction only. Although able to function as GTPases, the mutants of Rac1 that failed to interact with Rho-GDI also failed to activate the NADPH oxidase in a cell-free assay after loading with GTP. Mutant Leu119(Rac)Gln could both interact with Rho-GDI and activate the NADPH oxidase. The Rac1/Rho-GDI and Rac1(Leu119Gln)/Rho-GDI complexes, in which the GTPases were bound to GDP, were found to activate the oxidase efficiently. These data suggest that Rho-GDI stabilizes Rac in an active conformation, even in the GDP-bound state, and presents it to its effector, the p67phox component of the NADPH oxidase.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
28
pubmed:volume
40
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
10014-22
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:11513579-Amino Acid Sequence, pubmed-meshheading:11513579-Amino Acid Substitution, pubmed-meshheading:11513579-Animals, pubmed-meshheading:11513579-Baculoviridae, pubmed-meshheading:11513579-Cloning, Molecular, pubmed-meshheading:11513579-Enzyme Activation, pubmed-meshheading:11513579-Guanine Nucleotide Dissociation Inhibitors, pubmed-meshheading:11513579-Guanosine 5'-O-(3-Thiotriphosphate), pubmed-meshheading:11513579-Guanosine Diphosphate, pubmed-meshheading:11513579-Guanosine Triphosphate, pubmed-meshheading:11513579-Kinetics, pubmed-meshheading:11513579-Models, Molecular, pubmed-meshheading:11513579-Mutagenesis, Site-Directed, pubmed-meshheading:11513579-NADPH Oxidase, pubmed-meshheading:11513579-Protein Prenylation, pubmed-meshheading:11513579-Protein Structure, Secondary, pubmed-meshheading:11513579-Recombinant Proteins, pubmed-meshheading:11513579-Superoxides, pubmed-meshheading:11513579-Transfection, pubmed-meshheading:11513579-rac1 GTP-Binding Protein, pubmed-meshheading:11513579-rho GTP-Binding Proteins
pubmed:year
2001
pubmed:articleTitle
Mechanism of NADPH oxidase activation by the Rac/Rho-GDI complex.
pubmed:affiliation
Laboratoire de Biochimie et Biophysique des Systèmes Intégrés (BBSI)-UMR CEA/CNRS/UJF 5092, CEA Grenoble, 17 Rue des Martyrs, 38054 Grenoble Cedex 9, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't