Biology

Professor Dale Cameron and his lab team publish research on prions

Associate Professor of Biology, Dr. Dale Cameron, along with his former Honors student Ben Allwein (’18) and Research Assistant Dr. Christina Kelly, recently published their work on prions (view full text). Prions form when proteins adopt alternative structures that can assemble into ordered protein aggregates. These misshapen proteins can propagate their prion structures infectiously, converting other molecules of the same protein into the prion conformation. Prions are the cause of diseases like “mad cow” disease, scrapie in sheep, chronic wasting disease in deer, and Creutzfeldt-Jakob disease in humans.

The work published by Dr. Cameron’s team examines prions in yeast cells, which are single cell organisms widely used as models for biological research. Unlike the known mammalian prions, which are invariably associated with disease, yeast prions produce heritable traits that can be detrimental or beneficial. One such prion, called [PSI+], can be triggered by environmental stress and causes alterations in the way yeast cells make proteins. The resulting changes to the “proteome” - the entire collection of proteins contained by a cell at a given moment - can impact the way cells function, and even their ability to survive stressful environments.

Dr. Cameron’s latest work was carried out in collaboration with researchers at the University of British Columbia in Vancouver. Ben Allwein (’18), who conducted research with Dr. Cameron since his sophomore year at Ursinus and is now completing a Fulbright scholarship in India, spent the summer of 2017 at UBC examining differences between the proteomes of yeast cells with and without prions. Their work revealed that the [PSI+] prion triggers more extensive changes to the proteome in yeast cells under environmental stress. The prion-dependent changes in protein production that occur during stress are profoundly impacted by the particular prion structure adopted by the prion-forming protein and by existing genetic variation within the yeast cells. Moreover, these proteomic changes alter the cell’s growth and survival in diverse environmental conditions. Thus, the [PSI+] prion may be part of a biologically important mechanism for propagating altered cellular states that can increase diversity within a yeast population, and thereby enhance the potential of the population to adapt to changing environmental conditions.

Allwein B, Kelly C, Kammoonah S, Mayor T, Cameron DM. Prion-dependent proteome remodeling in response to environmental stress is modulated by prion variant and genetic background. (2019). Prion 13, 53-64