Garcia, David MDietrich, DavidClardy, JonJarosz, Daniel F2017-01-032016Garcia, David M, David Dietrich, Jon Clardy, and Daniel F Jarosz. 2016. “A common bacterial metabolite elicits prion-based bypass of glucose repression.” eLife 5 (1): e17978. doi:10.7554/eLife.17978. http://dx.doi.org/10.7554/eLife.17978.2050-084Xhttp://nrs.harvard.edu/urn-3:HUL.InstRepos:29739073Robust preference for fermentative glucose metabolism has motivated domestication of the budding yeast Saccharomyces cerevisiae. This program can be circumvented by a protein-based genetic element, the [GAR+] prion, permitting simultaneous metabolism of glucose and other carbon sources. Diverse bacteria can elicit yeast cells to acquire [GAR+], although the molecular details of this interaction remain unknown. Here we identify the common bacterial metabolite lactic acid as a strong [GAR+] inducer. Transient exposure to lactic acid caused yeast cells to heritably circumvent glucose repression. This trait had the defining genetic properties of [GAR+], and did not require utilization of lactic acid as a carbon source. Lactic acid also induced [GAR+]-like epigenetic states in fungi that diverged from S. cerevisiae ~200 million years ago, and in which glucose repression evolved independently. To our knowledge, this is the first study to uncover a bacterial metabolite with the capacity to potently induce a prion. DOI: http://dx.doi.org/10.7554/eLife.17978.001en-USlactic acidprioncatabolite repressionmolecular communicationOtherJournal Article2017-01-0310.7554/eLife.17978