Figure 3. Diagrammatic representation of cellular stress responses. Under unstressed conditions, heat shock factor-1 (HSF-1) remains in a complex with heat shock protein 70 (HSP70) and heat shock protein 90 (HSP90). When the cell is challenged with stress, HSF-1 dissociates from the complex, undergoes post-translational modification and trimerization, and translocate to the nucleus. It binds to the heat shock element in the promoter and activates the expression of cytosolic chaperones, thus providing cellular protection [52-55].