GTP-binding proteins in plants: new members of an old family

Plant Mol Biol. 1994 Dec;26(5):1611-36. doi: 10.1007/BF00016493.


Regulatory guanine nucleotide-binding proteins (G proteins) have been studied extensively in animal and microbial organisms, and they are divided into the heterotrimeric and the small (monomeric) classes. Heterotrimeric G proteins are known to mediate signal responses in a variety of pathways in animals and simple eukaryotes, while small G proteins perform diverse functions including signal transduction, secretion, and regulation of cytoskeleton. In recent years, biochemical analyses have produced a large amount of information on the presence and possible functions of G proteins in plants. Further, molecular cloning has clearly demonstrated that plants have both heterotrimeric and small G proteins. Although the functions of the plant heterotrimeric G proteins are yet to be determined, expression analysis of an Arabidopsis G alpha protein suggests that it may be involved in the regulation of cell division and differentiation. In contrast to the very few genes cloned thus far that encode heterotrimeric G proteins in plants, a large number of small G proteins have been identified by molecular cloning from various plants. In addition, several plant small G proteins have been shown to be functional homologues of their counterparts in animals and yeasts. Future studies using a number of approaches are likely to yield insights into the role plant G proteins play.

Publication types

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

MeSH terms

  • Animals
  • Eukaryotic Cells / physiology
  • GTP-Binding Proteins / classification
  • GTP-Binding Proteins / genetics
  • GTP-Binding Proteins / metabolism*
  • Genes, Plant / genetics*
  • Guanosine Triphosphate / metabolism
  • Plant Physiological Phenomena*
  • Plants / genetics
  • Plants, Genetically Modified
  • Signal Transduction / genetics
  • Signal Transduction / physiology*
  • Yeasts / genetics


  • Guanosine Triphosphate
  • GTP-Binding Proteins