2Vavilov Institute of General Genetics, Russian Academy of Sciences, ul. Gubkina 3, 119991 Moscow, Russia; fax: (499) 132-8962; E-mail: email@example.com
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Received February 10, 2012; Revision received February 25, 2012
Although high level of recombinant protein production can be achieved via transient expression in plant cells, the mechanism by which tolerance to the presence of recombinant protein is acquired remains unclear. Here we show that green fluorescent protein (GFP) encoded by an intron-optimized tobacco mosaic viral vector formed large membraneless GFP bodies called Y-bodies that demonstrated mainly perinuclear localization. The Y-bodies were heterogeneous in size, approaching the size of the cell nucleus. Experiments with extracted GFP and live cell imaging showed that Y-bodies included actively fluorescent, non-aggregated, tightly packed GFP molecules. The plant cells probably formed Y-bodies to exclude the recombinant protein from normal physiological turnover.
KEY WORDS: Agrobacterium tumefaciens, green fluorescent protein (GFP), viral vector, Y-bodies, tobacco mosaic virus, transient expression