| Abstract [eng] |
Saccharomyces cerevisiae is a widely used organism in various industrial and scientific fields. Viruses of Orthototiviridae family, including ScV-LA, ScV-LBC and ScV-M satellites can be found in many S. cerevisiae strains. These viruses may be associated with the host cell’s phenotype and influence the evolutionary dynamics of yeast populations. For example, the coexistence of the ScV-M satellite and helper ScV-LA is a key factor determining the yeast’s killer activity. Totiviruses lack an extracellular phase and can only replicate during cell division. It was previously thought that ScV-LA and ScV-LBC viruses had no clear effect on S. cere-visiae, but over the past decade it was shown that the interaction of Totiviruses with the host cell is more complex. ScV-LA may be associated with changes in S. cerevisiae gene expression, metabo-lism and antiviral systems. This implies that various cellular compartments may directly or indirect-ly interact with Totiviruses. However, the translocation of ScV-LA and ScV-LBC within cells re-mains unknown. The aim of this study is to identify potential factors influencing the localization of ScV-LA and ScV-LBC viral capsid proteins in S. cerevisiae cells. The study involved an analysis of the localization of recombinant ScV-LA and ScV-LBC Gag proteins using fluorescence microscopy. This study revealed that a shift in the -1 ribosomal frame alters the amino acid composition and biochemical properties of the C-terminal fragments of the ScV-LA and ScV-LBC Gag proteins. These changes may be related to protein translocation. In the absence of a -1 ribosomal frameshift, Gag proteins accumulate in the cytoplasm. However, upon occurrence of a -1 ribosomal frameshift, ScV-LA Gag proteins localize in or near nucleus in addition overlapping with endoplasmic reticu-lum and microtubule structures. Unlike ScV-LA, ScV-LBC Gag proteins following -1 ribosomal frameshift localize in vesicle-like structures scattered throughout the cytoplasm. It has also been found that the native Totiviruses or ploidy in S. cerevisiae does not affect localization of ScV-LA and ScV-LBC Gag proteins. |
