Heat shock response
The heat shock response (HSR) is a cell stress response that increases the number of molecular chaperones to combat the negative effects on proteins caused by stressors such as increased temperatures, oxidative stress, and heavy metals. In a normal cell, proteostasis (protein homeostasis) must be maintained because proteins are the main functional units of the cell. Many proteins take on a defined configuration in a process known as protein folding in order to perform their biological functions. If these structures are altered, critical processes could be affected, leading to cell damage or death. The heat shock response can be employed under stress to induce the expression of heat shock proteins (HSP), many of which are molecular chaperones, that help prevent or reverse protein misfolding and provide an environment for proper folding.Protein folding is already challenging due to the crowded intracellular space where aberrant interactions can arise; it becomes more difficult when environmental stressors can denature proteins and cause even more non-native folding to occur. If the work by molecular chaperones is not enough to prevent incorrect folding, the protein may be degraded by the proteasome or autophagy to remove any potentially toxic aggregates. Misfolded proteins, if left unchecked, can lead to aggregation that prevents the protein from moving into its proper conformation and eventually leads to plaque formation, which may be seen in various diseases. Heat shock proteins induced by the HSR can help prevent protein aggregation that is associated with common neurodegenerative diseases such as Alzheimer's, Huntington's, or Parkinson's disease.