Plant Molecular Biology

, Volume 39, Issue 4, pp 647–656

GRAB proteins, novel members of the NAC domain family, isolated by their interaction with a geminivirus protein

  • Qi Xie
  • Andrés P. Sanz-Burgos
  • Huishan Guo
  • Juan Antonio García
  • Crisanto Gutiérrez
Article

DOI: 10.1023/A:1006138221874

Cite this article as:
Xie, Q., Sanz-Burgos, A.P., Guo, H. et al. Plant Mol Biol (1999) 39: 647. doi:10.1023/A:1006138221874

Abstract

Geminiviruses encode a few proteins and depend on cellular factors to complete their replicative cycle. As a way to understand geminivirus-host interactions, we have searched for cellular proteins which interact with viral proteins. By using the yeast two-hybrid technology and the wheat dwarf geminivirus (WDV) RepA protein as a bait, we have isolated a family of proteins which we termed GRAB (for Geminivirus Rep A-binding). We report here the molecular characterization of two members, GRAB1 and GRAB2. We have found that the 37 C-terminal amino acids of RepA are required for interaction with GRAB proteins. This region contains residues conserved in an equivalent region of the RepA proteins encoded by other viruses of the WDV subgroup. The N-terminal domain of GRAB proteins is necessary and sufficient to interact with WDV RepA. GRAB proteins contain an unique acidic C-terminal domain while their N-terminal domain, of ca. 170 amino acids, are highly conserved in all of them. Interestingly, this conserved N-terminal domain of GRAB proteins exhibits a significant amino acid homology to the NAC domain present in proteins involved in plant development and senescence. GRAB1 and GRAB2 mRNAs are present in cultured cells and roots but are barely detectable in leaves. GRAB expression inhibits WDV DNA replication in cultured wheat cells. Our studies highlight the importance that the pathway(s) mediated by GRAB proteins, as well as by other NAC domain-containing proteins, might have on geminivirus DNA replication in connection to plant growth, development and senescence pathways.

geminivirusDNA replicationplant growthsenescenceNAC domain

Copyright information

© Kluwer Academic Publishers 1999

Authors and Affiliations

  • Qi Xie
    • 1
  • Andrés P. Sanz-Burgos
    • 1
  • Huishan Guo
    • 2
  • Juan Antonio García
    • 2
  • Crisanto Gutiérrez
    • 1
  1. 1.Centro de Biología Molecular 'Severo Ochoa' (CSIC-UAM)Universidad Autónoma, CantoblancoMadridSpain
  2. 2.Centro Nacional de Biotecnología (CSIC), Campus de CantoblancoMadridSpain