1 PROTEIN EXPRESSION REGULATION UNDER OXIDATIVE STRESS

Oxidative stress is known to affect both translation and protein turnover, but very few large-scale studies describe protein expression under stress. We measure protein concentrations in Saccharomyces cerevisiae over the course of two hours in response to a mild oxidative stress induced by diamide, providing detailed time-resolved information for 815 proteins, with additional data for another ~1,100 proteins. For the majority of proteins, we discover major differences between the global transcript and protein response. While mRNA levels often return to baseline one hour after treatment, protein concentrations continue to change. Integrating our data with features of translation and protein degradation, we are able to predict expression patterns for 41 % of the proteins in the core dataset. Predictive features include, amongst others, targeting by RNA-binding proteins (Lhp1, Khd1), RNA secondary structures, RNA half-life, and translation efficiency under unperturbed conditions and in response to oxidative reagents – but not chaperone binding. We are able to both describe general dynamics of protein concentration changes, and to suggest possible regulatory mechanisms for individual proteins. words: 169