σ32 controls the heat-shock response in bacteria. This involves upregulating the expression of chaperone and protease genes to help maintain the cell’s function.
At higher temperatures, secondary protein structure can change, especially in heat labile proteins. Where a protein denatures, it becomes dysfunctional and must be degraded to prevent the cytoplasm from becoming congested. Special proteases (denaturation enzymes) can be used to degrade denatured proteins.
The cell can also use σ32 to change the lipid composition in its membrane, making it more gel-like to prevent the cell from leaking. This improves stability, but takes more time than upregulating specific proteins.