"HETEROLOGOUS EXPRESSION OF A PLANT VIRUS PROTEIN CHANGED THE NATURE OF ACETIC ACID-INDUCED CELL DEATH IN SACCHAROMYCES CEREVISIAE"

"A highly conserved feature of positive-strand RNA viruses is the association of the viral replication complex with specific intracellular membranes, which are induced to proliferate and are extensively rearranged to form vesicles, where virus replication occurs. Virusencoded proteins are responsible for the intracellular localization of the replication complex and for the formation of vesicles. Carnation Italian ringspot virus (CIRV, genus Tombusvirus, family Tombusviridae) replication takes place in membranous structures, originating from the vesiculation of the mitochondrial outer membrane. CIRV p36 is required for targeting and anchoring CIRV replication to the outer membrane of mitochondria in plant and yeast cells. Since many DNA and RNA virus proteins have been reported to behave as proapoptotic or antiapoptotic viral factors, either by direct or indirect interaction with the mitochondrial outer membrane, Saccharomyces cerevisiae was used as a model to study the possible role of CIRV p36 on cell survival and death. It was shown that p36 expression affected cell growth rate, but did not promote cell death. p36 could change the nature of acetic acid-induced cell death in yeast from apoptosis-like to necrosis. Acetic acid treatment did not impair the strict association of p36 with mitochondrial membranes, thus confirming the independent interaction of p36 with mitochondria. Yeast proved to be a model organism for studying the mitochondrial determinants of cell death mode, as well as the molecular pathogenesis of (+)RNA viruses and the mechanisms for the induction of necrosis in infected plants."