Interactions between Rho GTPases and Rho GDP dissociation inhibitor (Rho-GDI)

• Published in: Biochimie 2001-05, Vol.83 (5), p.409-414
• Main Authors: Fauré, Julien, Dagher, Marie-Claire
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; beta-Galactosidase; DNA, Complementary; DNA, Complementary - metabolism; Gene Library; Glutathione Transferase; Glutathione Transferase - metabolism; Guanine Nucleotide Dissociation Inhibitors; Guanine Nucleotide Dissociation Inhibitors - chemistry; Guanine Nucleotide Dissociation Inhibitors - metabolism; Humans; Immunology; Innate immunity; Leukocytes; Leukocytes - metabolism; Life Sciences; Lipid Metabolism; Molecular Sequence Data; Mutation; prenylation; Protein Binding; Protein Prenylation; Protein Structure, Tertiary; Recombinant Fusion Proteins; Recombinant Fusion Proteins - metabolism; Rho GDP dissociation inhibitor; rho GTP-Binding Proteins; rho GTP-Binding Proteins - chemistry; rho GTP-Binding Proteins - metabolism; Rho GTPases; rho-Specific Guanine Nucleotide Dissociation Inhibitors; Sequence Homology, Amino Acid; two-hybrid system; Two-Hybrid System Techniques
• ISSN: 0300-9084; 1638-6183
• DOI: 10.1016/S0300-9084(01)01263-9

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.