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Suppression of post‐transcriptional gene silencing by a plant viral protein localized in the nucleus
Author(s) -
Lucy Andrew P.,
Guo HuiShan,
Li WanXiang,
Ding ShouWei
Publication year - 2000
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/19.7.1672
Subject(s) - biology , gene silencing , nucleus , gene , genetics , microbiology and biotechnology
Post‐transcriptional gene silencing (PTGS) is a homology‐dependent RNA degradation process that may target RNA exclusively in the cytoplasm. In plants, PTGS functions as a natural defense mechanism against viruses. We reported previously that the 2b protein encoded by cucumber mosaic cucumovirus (CMV) is a virulence determinant and a suppressor of PTGS initiation in transgenic Nicotiana benthamiana . By fusion with the green fluorescent protein, we now show that the CMV 2b protein localizes to the nuclei of tobacco suspension cells and whole plants via an arginine‐rich nuclear localization signal, 22 K 27 . We further demonstrate that the nuclear targeting of the 2b protein is required for the efficient suppression of PTGS, indicating that PTGS may be blocked in the nucleus. In addition, our data indicate that the PTGS suppressor activity is important, but not sufficient, for virulence determination by the 2b protein.