Data from: Reversible, specific, active aggregates of endogenous proteins assemble upon heat stress

Heat causes protein misfolding and aggregation and in eukaryotic cells
triggers aggregation of proteins and RNA into stress granules. We have
carried out extensive proteomic studies to quantify heat-triggered
aggregation and subsequent disaggregation in budding yeast, identifying
>170 endogenous proteins aggregating within minutes of heat shock
in multiple subcellular compartments. We demonstrate that these aggregated
proteins are not misfolded and destined for degradation. Stable-isotope
labeling reveals that even severely aggregated endogenous proteins are
disaggregated without degradation during recovery from shock, contrasting
with the rapid degradation observed for exogenous thermolabile proteins.
Although aggregation likely inactivates many cellular proteins, in the
case of a heterotrimeric aminoacyl-tRNA synthetase complex, the aggregated
proteins remain active with unaltered fidelity. We propose that most
heat-induced aggregation of mature proteins reflects the operation of an
adaptive, autoregulatory process of functionally significant aggregate
assembly and disassembly that aids cellular adaptation to thermal stress.