Interactions between Rho GTPases and Rho GDP dissociation inhibitor (Rho-GDI).
The Rho-GDP dissociation inhibitor (Rho-GDI) was used as bait in a two-hybrid screen of a human leucocyte cDNA library. Most of the isolated cDNAs encoded GTPases of the Rho subfamily: RhoA, B, C, Rac1, 2, CDC42 and RhoG. The newly discovered RhoH interacted very poorly with Rho-GDI. Another protein partner shared a homology with RhoA that points to Asp67(RhoA)-Arg68(RhoA)-Leu69(RhoA) as critical for interaction with Rho-GDI. A second screen with RhoA as bait led to the isolation of GDI only. In order to investigate the relative role of protein-protein and protein-lipid interactions between Rho GTPases and Rho-GDI, CAAX box mutants of RhoA were produced. They were found to interact with Rho-GDI as efficiently as wild type RhoA, indicating that protein-protein interactions alone lead to strong binding of the two proteins. The C-terminal polybasic region of RhoA was also shown to be a site of protein-protein interaction with Rho-GDI.
Fauré
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Laboratoire de Biochimie et Biophysique des Systèmes Intégrés (BBSI), UMR CEA/CNRS/UJF 5092, CEA Grenoble, 17, rue des Martyrs, 38054 cedex 9, Grenoble, France.
Dagher
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MC
D000595:Amino Acid Sequence; D018076:DNA, Complementary / Q000378:metabolism; D015723:Gene Library; D005982:Glutathione Transferase / Q000378:metabolism; D020730:Guanine Nucleotide Dissociation Inhibitors / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D007962:Leukocytes / Q000378:metabolism; D050356:Lipid Metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D011485:Protein Binding; D017368:Protein Prenylation; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D020798:Two-Hybrid System Techniques; D001616:beta-Galactosidase; D020741:rho GTP-Binding Proteins / Q000737:chemistry* / Q000378:metabolism*; D062947:rho-Specific Guanine Nucleotide Dissociation Inhibitors
D018076:DNA, Complementary; D020730:Guanine Nucleotide Dissociation Inhibitors; D011993:Recombinant Fusion Proteins; D062947:rho-Specific Guanine Nucleotide Dissociation Inhibitors; D005982:Glutathione Transferase; D001616:beta-Galactosidase; D020741:rho GTP-Binding Proteins