Ribosome-associated GTPases: the role of RNA for GTPase activation

RNA Biol. Sep-Oct 2010;7(5):521-7. doi: 10.4161/rna.7.5.12467. Epub 2010 Sep 1.

Abstract

The GTPase super-family comprises a variety of G proteins found in all three domains of life. Although they are participating in completely different processes like signal transduction, protein biosynthesis and regulation of cell proliferation, they all share a highly conserved G domain and use a common mechanism for GTP hydrolysis. Exact timing in hydrolyzing the bound GTP serves as a molecular switch to initiate diverse cellular reactions. Classical GTPases depend on external proteins to fire GTP hydrolysis (GAPs), and following the GTPase reaction to exchange GDP for GTP (GEFs), converting the GTPase into the active state again. In recent years it became clear that there are many GTPases that do not follow this classical switch mode scheme. Certain ribosome-associated GTPases are not reliant on other GEF proteins to exchange GDP for GTP. Furthermore many of these G proteins are not activated by external GAPs, but by evolutionarily ancient molecules, namely by RNA.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Bacteria / metabolism
  • GTP Phosphohydrolase Activators / metabolism*
  • GTP Phosphohydrolase-Linked Elongation Factors / metabolism
  • GTP Phosphohydrolases / metabolism*
  • GTP-Binding Proteins / metabolism
  • Humans
  • RNA / metabolism*
  • Ribosomes / enzymology*
  • Ribosomes / metabolism

Substances

  • GTP Phosphohydrolase Activators
  • RNA
  • GTP Phosphohydrolase-Linked Elongation Factors
  • GTP Phosphohydrolases
  • GTP-Binding Proteins