Novel G proteins, Rag C and Rag D, interact with GTP-binding proteins, Rag A and Rag B

J Biol Chem. 2001 Mar 9;276(10):7246-57. doi: 10.1074/jbc.M004389200. Epub 2000 Nov 9.

Abstract

Rag A/Gtr1p are G proteins and are known to be involved in the RCC1-Ran pathway. We employed the two-hybrid method using Rag A as the bait to identify proteins binding to Rag A, and we isolated two novel human G proteins, Rag C and Rag D. Rag C demonstrates homology with Rag D (81.1% identity) and with Gtr2p of Saccharomyces cerevisiae (46.1% identity), and it belongs to the Rag A subfamily of the Ras family. Rag C and Rag D contain conserved GTP-binding motifs (PM-1, -2, and -3) in their N-terminal regions. Recombinant glutathione S-transferase fusion protein of Rag C efficiently bound to both [(3)H]GTP and [(3)H]GDP. Rag A was associated with both Rag C and Rag D in their C-terminal regions where a potential leucine zipper motif and a coiled-coil structure were found. Rag C and D were associated with both the GDP and GTP forms of Rag A. Both Rag C and Rag D changed their subcellular localization, depending on the nucleotide-bound state of Rag A. In a similar way, the disruption of S. cerevisiae GTR1 resulted in a change in the localization of Gtr2p.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Motifs
  • Amino Acid Sequence
  • Binding Sites
  • Cell Line
  • Cell Nucleus / metabolism
  • Dimerization
  • Dose-Response Relationship, Drug
  • Fungal Proteins / chemistry
  • Fungal Proteins / metabolism
  • GTP-Binding Proteins*
  • Glutathione Transferase / metabolism
  • Guanosine Diphosphate / metabolism
  • Guanosine Triphosphate / metabolism
  • HeLa Cells
  • Humans
  • Immunoblotting
  • Leucine / chemistry
  • Microscopy, Fluorescence
  • Models, Genetic
  • Molecular Sequence Data
  • Monomeric GTP-Binding Proteins / chemistry*
  • Monomeric GTP-Binding Proteins / genetics*
  • Monomeric GTP-Binding Proteins / metabolism
  • Nucleotides / metabolism
  • Precipitin Tests
  • Protein Binding
  • Protein Structure, Tertiary
  • Recombinant Fusion Proteins / metabolism
  • Recombinant Proteins / metabolism
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins*
  • Sequence Homology, Amino Acid
  • Time Factors
  • Transfection
  • Two-Hybrid System Techniques
  • beta-Galactosidase / metabolism

Substances

  • Fungal Proteins
  • GTR2 protein, S cerevisiae
  • Nucleotides
  • RRAGC protein, human
  • RRAGD protein, human
  • Recombinant Fusion Proteins
  • Recombinant Proteins
  • Saccharomyces cerevisiae Proteins
  • Guanosine Diphosphate
  • Guanosine Triphosphate
  • Glutathione Transferase
  • beta-Galactosidase
  • GTP-Binding Proteins
  • RRAGA protein, human
  • RRAGB protein, human
  • Monomeric GTP-Binding Proteins
  • Leucine

Associated data

  • GENBANK/AF272035
  • GENBANK/AF272036