Open AccessA bacterial peptide acting as a plant nuclear targeting signal: the amino-terminal portion of Agrobacterium VirD2 protein directs a beta-galactosidase fusion protein into tobacco nuclei.
Author(s) -
Alfredo Herrera-Estrella,
Marc Van Montagu,
K Wang
Publication year - 1990
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.87.24.9534
Subject(s) - agrobacterium tumefaciens , nuclear localization sequence , biology , fusion protein , agrobacterium , signal peptide , gene , microbiology and biotechnology , plasmid , cytoplasm , biochemistry , transgene , peptide sequence , recombinant dna
Agrobacterium tumefaciens is a soil bacterium capable of transferring DNA to the genome of higher plants. Of the virulence region-encoded proteins of the tumor-inducing (Ti) plasmid of A. tumefaciens, the VirD1 and VirD2 proteins are essential for T-DNA transfer to plant cells. These two proteins have been shown to be directly responsible for the formation of T-strands. VirD2 was also shown to be firmly attached to the 5' termini of T-strands; these facts have led to its postulation as a pilot protein in the T-DNA transfer process and as a nucleus-targeting signal in plants. We have constructed a chimeric gene by fusing the virD2 gene and the Escherichia coli lacZ gene. Cell fractionation and electron microscopy studies with transgenic tobacco plants containing the VirD2-LacZ fusion protein indicate that the first 292 amino acids of VirD2 are able to direct the cytoplasmic protein beta-galactosidase to the plant nucleus. This provides an example of cross-kingdom nuclear localization between two free-living organisms: a bacterial peptide is capable of acting as a eukaryotic (plant) nuclear targeting signal.