A conserved chromatin complex is sumoylated during acute ethanol stress in Saccharomyces cerevisiae

Abstract

University of WashingtonAbstract Acute ethanol stress induces sumoylation of conserved chromatin proteins in Saccharomyces cerevisiae Amanda I Bradley Chair of Supervisory Committee: Professor Sue Biggins Department of Biochemistry (UW), Basic Sciences Division (FHCRC) Stress is a ubiquitous part of life which disrupts cellular function and, if unresolved, can irreparably damage essential biomolecules and organelles. All organisms are subject to stress in the form of unfavorable environmental conditions including extreme temperatures, hypoxia, reactive oxygen species, or shifts in osmolarity. To survive, organisms must sense these changes then react and adapt. One highly conserved adaptive response is sumoylation, which is a post-translational modification by the small ubiquitin-like modifier (SUMO) protein. SUMO is a broadly used signaling molecule capable of altering protein localization, interactions, solubility, regulating transcription and genomic integrity. In the context of environmental stresses, I find that Saccharomyces cerevisiae (budding yeast) exhibit unique and dynamic patterns of sumoylation as part of a concerted effort to return the cell to homeostatic conditions. These SUMO-based stress responses vary in kinetics and substrates in accordance with the type, severity, and duration of stress. I therefore conclude that, rather than employing a generalized SUMO stress response, yeast tailor their use of this highly versatile modification to suit the present environmental conditions.