СУБКЛЕТОЧНАЯ ЛОКАЛИЗАЦИЯ И ДЕТЕКЦИЯ БЕЛКА ОРТ6 ВИРУСА ТАБАЧНОЙ МОЗАИКИ С ПОМОЩЬЮ ИММУНОЭЛЕКТРОННОЙ МИКРОСКОПИИ  : Subcellular Localization and Detection of Tobacco mosaic virus ORF6 Protein by Immunoelectron Microscopy

The Tobamovirus genus is one of the best-characterized groups of plant viruses. In previous studies, it was found that the genomes of some tobamoviruses encode, in addition to well-known polypeptides (RNA polymerase, movement protein, and coat protein), a positively charged and poorly conserved small protein encoded by a small cistron (so-called open reading frame 6 – «ORF6»). The amino acid sequences of the ORF6 proteins encoded by different tobamoviruses are often only marginally related. In this work, we used immunogold labeling and electron microscopy to confirm the in vivo expression of ORF6 and to study its subcellular localization. It was experimentally found that two isolates of tobacco mosaic virus strain U1 directed the synthesis of ORF6 peptide. The product of ORF6 is main ly found in nuclei, which is in accordance with previously published data on transient expression of the isolated ORF6. In addition, we present new data on the diversity of ORF6 proteins and other poorly conserved proteins encoded by tobamoviral RNA viromes.