Functional identification of multiple nucleocytoplasmic trafficking signals in the broad-spectrum resistance protein RPW8.2

Planta. 2014 Feb;239(2):455-68. doi: 10.1007/s00425-013-1994-x. Epub 2013 Nov 12.

Abstract

Nuclear localization signals (NLSs) and nuclear export signals (NESs) are important intramolecular regulatory elements for protein nucleocytoplasmic trafficking. This regulation confers spatial specificity to signal initiation and transduction in eukaryotic cells and thus is fundamental to the viability of all eukaryotic organisms. Here, we developed a simple and rapid method in which activity of putative NLSs or NESs was reported by subcellular localization of two tandem fluorescent proteins in fusion with the respective NLSs or NESs after agroinfiltration-mediated transient expression in leaves of Nicotiana benthamiana (Nb). We further demonstrated that the predicted NES from amino acid residue (aa) 9 to 22 and the NLS from aa91 to 101 in the broad-spectrum disease resistance protein RPW8.2 possess nuclear export and import activity, respectively. Additionally, by testing overlapping fragments covering the full length of RPW8.2, we identified another NLS from aa65 to 74 with strong nuclear import activity and two tandem non-canonical NESs in the C-terminus with strong nuclear export activity. Taken together, our results demonstrated the utility of a simple method to evaluate potential NLSs and NESs in plant cells and suggested that RPW8.2 may be subject to opposing nucleocytoplasmic trafficking forces for its subcellular localization and functional execution.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Arabidopsis / genetics
  • Arabidopsis / metabolism
  • Arabidopsis Proteins / chemistry
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Cell Nucleus / metabolism
  • Cytoplasm / metabolism
  • Genes, Reporter
  • Molecular Sequence Data
  • Mutation
  • Nicotiana / cytology
  • Nicotiana / genetics
  • Nicotiana / metabolism*
  • Nuclear Export Signals*
  • Nuclear Localization Signals*
  • Plant Leaves / cytology
  • Plant Leaves / genetics
  • Plant Leaves / metabolism
  • Plants, Genetically Modified
  • Protein Transport
  • Recombinant Fusion Proteins
  • Sequence Analysis, DNA
  • Signal Transduction*

Substances

  • Arabidopsis Proteins
  • Nuclear Export Signals
  • Nuclear Localization Signals
  • RPW8.2 protein, Arabidopsis
  • Recombinant Fusion Proteins