Researching the Kiss of Death

Superheroes of Science

Proteins perform a lot of different jobs within our cells. As proteins either age or mutate, they can begin to cause problems for the cells. The ubiquitin system, (present only in eukaryotic organisms - animals and plants), works to tag proteins that go bad. Proteins tagged by the ubiquitin system send a signal to proteasomes which then shred the bad protein, hence the expression “kiss of death.” Normally, a cell infected by a pathogen, (bacterium or virus), will undergo a process known as xenophagy, where an infected cell will kill itself to avoid becoming infectious to other cells around it. At the same time, the process of xenophagy kills the pathogens causing the infection. Even though pathogens don’t have a ubiquitin system, they have adapted their ability to survive by producing proteins that hijack the ubiquitin system of eukaryotic cells. Sebastian Kenny, PhD candidate the Department of Chemistry at Purdue University, explains the research he is doing to learn more about how pathogens are able to hijack the ubiquitin system.