@article{mbs:/content/journal/jgv/10.1099/vir.0.045278-0, author = "Gushchin, Vladimir A. and Lukhovitskaya, Nina I. and Andreev, Dmitri E. and Wright, Kathryn M. and Taliansky, Michael E. and Solovyev, Andrey G. and Morozov, Sergey Y. and MacFarlane, Stuart A.", title = "Dynamic localization of two tobamovirus ORF6 proteins involves distinct organellar compartments", journal= "Journal of General Virology", year = "2013", volume = "94", number = "1", pages = "230-240", doi = "https://doi.org/10.1099/vir.0.045278-0", url = "https://www.microbiologyresearch.org/content/journal/jgv/10.1099/vir.0.045278-0", publisher = "Microbiology Society", issn = "1465-2099", type = "Journal Article", abstract = "ORF6 is a small gene that overlaps the movement and coat protein genes of subgroup 1a tobamoviruses. The ORF6 protein of tomato mosaic virus (ToMV) strain L (L-ORF6), interacts in vitro with eukaryotic elongation factor 1α, and mutation of the ORF6 gene of tobacco mosaic virus (TMV) strain U1 (U1-ORF6) reduces the pathogenicity in vivo of TMV, whereas expression of this gene from two other viruses, tobacco rattle virus (TRV) and potato virus X (PVX), increases their pathogenicity. In this work, the in vivo properties of the L-ORF6 and U1-ORF6 proteins were compared to identify sequences that direct the proteins to different subcellular locations and also influence virus pathogenicity. Site-specific mutations in the ORF6 protein were made, hybrid ORF6 proteins were created in which the N-terminal and C-terminal parts were derived from the two proteins, and different subregions of the protein were examined, using expression either from a recombinant TRV vector or as a yellow fluorescent protein fusion from a binary plasmid in Agrobacterium tumefaciens. L-ORF6 caused mild necrotic symptoms in Nicotiana benthamiana when expressed from TRV, whereas U1-ORF6 caused severe symptoms including death of the plant apex. The difference in symptoms was associated with the C-terminal region of L-ORF6, which directed the protein to the endoplasmic reticulum (ER), whereas U1-ORF6 was directed initially to the nucleolus and later to the mitochondria. Positively charged residues at the N terminus allowed nucleolar entry of both U1-ORF6 and L-ORF6, but hydrophobic residues at the C terminus of L-ORF6 directed this protein to the ER.", }