Plant rac proteins induce superoxide production in mammalian cells

Biochem Biophys Res Commun. 2000 Jun 16;272(3):783-8. doi: 10.1006/bbrc.2000.2791.


The small GTP-binding protein family including Rac proteins represents a paradigm for signaling molecules shared by animal and plants. In mammalian cells, Rac induces the activation of NADPH oxidase leading to superoxide production. In plants, evidence suggests that resistance to pathogens depends on superoxide that is generated via NADPH oxidase-like enzymes. We have identified four closely related Rho/Rac genes from Zea mays that exhibit a high degree of homology to the human Rac. We hypothesized that these plant Rac proteins could function as their mammalian counterpart and activate an enzymatic complex that leads to superoxide production. Here, we show that like human Rac1, activated Zea mays Rac genes can induce superoxide production, when expressed in a mammalian system: NIH 3T3 cells. Our results suggest that in plants, Rac proteins can function as activators of oxidative burst and indicate the remarkable functional and structural conservation of Rho/Rac proteins between plant and animal kingdoms during evolution.

Publication types

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

MeSH terms

  • 3T3 Cells
  • Amino Acid Sequence
  • Animals
  • Conserved Sequence / genetics
  • Electron Spin Resonance Spectroscopy
  • Enzyme Activation
  • Evolution, Molecular
  • Genes, Dominant / genetics
  • Genes, Plant / genetics
  • Humans
  • Mice
  • Molecular Sequence Data
  • Mutation / genetics
  • Plant Proteins / chemistry
  • Plant Proteins / genetics
  • Plant Proteins / metabolism*
  • Protein Isoforms / chemistry
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism
  • RNA, Messenger / analysis
  • RNA, Messenger / genetics
  • Reactive Oxygen Species / metabolism
  • Respiratory Burst / genetics
  • Sequence Alignment
  • Superoxides / metabolism*
  • Zea mays / genetics*
  • rac GTP-Binding Proteins / chemistry
  • rac GTP-Binding Proteins / genetics
  • rac GTP-Binding Proteins / metabolism*
  • rac1 GTP-Binding Protein / chemistry
  • rac1 GTP-Binding Protein / genetics
  • rac1 GTP-Binding Protein / metabolism


  • Plant Proteins
  • Protein Isoforms
  • RNA, Messenger
  • Reactive Oxygen Species
  • Superoxides
  • rac GTP-Binding Proteins
  • rac1 GTP-Binding Protein

Associated data

  • GENBANK/AF126052
  • GENBANK/AF126053
  • GENBANK/AF126054
  • GENBANK/AF126055