When I think of the words killer and assassin, my mind drifts to shady men in all black equipped with sniper rifles. However, recent research conducted by the University of Idaho and the University of Colorado Boulder has indicated that I should expand that mental list to include XRN1, a gene in saccharomyces cerevisiae which, according to a recent study, kills viruses within the yeast. Upon stumbling onto this subject, I was intrigued because it was a fairly simple procedure that led to a huge discovery. To grasp the significance of such a discovery, one must understand it on a molecular level. XRN1’s duty in yeasts is to create a protein which breaks down old RNA. The image below shows the generic process of the creation of a new protein through gene regulation.
Yeasts also contain viral RNA since practically all yeasts are infected by viruses. When scientists removed XRN1 from the yeasts, the viruses within yeasts replicated much faster, and when they expressed high amounts of XRN1, the virus was completely eradicated. This is because the XRN1 gene was inadvertently breaking down the viral RNA, mistakenly taking it for the yeast’s RNA. Scientists continued the research by using XRN1 from other saccharomyces yeast species. The virus continued replicating rapidly but the XRN1 did continue its job of breaking down the yeast’s RNA. This shows that the XRN1 from each yeast species evolves to attack the specific viruses that occur in its host while still maintaining their basic role as the RNA eaters. Scientists are hopeful about this study’s human health implications. Viruses such as Polio and Hepatitis C work by degrading XRN1 and not allowing it to break down RNA, respectively. Dengue Fever also occurs when XRN1 is unable to perform its function of RNA breakdown. These studies on Dengue Fever and Hepatitis C elaborate on the implications of XRN1 not breaking down RNA. Scientists hope that this discovery could lead to the triumph of XRN1 over these viruses. Could this really be the discovery that leads to the first ever Hepatitis C vaccine? Do you think that XRN1’s success against virus in yeasts guarantees eventual success against viruses in humans?
Original Article: http://phys.org/news/2016-10-yeast-gene-rapidly-evolves-viruses.html