Final answer:
The chaperones found in the ER that assist with protein folding belong to the Heat Shock Protein family, with Hsp70 playing a key role in binding to and assisting unfolded proteins. Heat shock induces the activation and increased production of Hsp70 to prevent aggregation and refold misfolded proteins, ensuring cellular protein homeostasis.
Step-by-step explanation:
The chaperones found in the ER that respond to misfolded and unfolded proteins belong to the family of Heat Shock Proteins. Among them, Hsp70 (Heat Shock Protein 70) is the primary chaperone in the ER that recognizes and binds to unfolded proteins to assist in their proper folding. The activity of these chaperones, including Hsp70, is upregulated in response to stress conditions, such as increased temperature (heat shock), changes in pH, and the presence of certain chemicals.
When a cell undergoes heat shock, the increased temperature can lead to proteins misfolding. Heat shock proteins like Hsp70 are then released from complexes and become active to refold these misfolded proteins. Additionally, transcription of HSP genes is activated in response to such stress to produce more chaperones, ensuring that the cell can cope with the unfolding and potential aggregation of proteins during these stressful conditions.
The role of chaperones in the ER, specifically Hsp70, is crucial for maintaining protein homeostasis within the cell. By assisting the proper folding of proteins, these chaperones ensure that cellular functions continue smoothly and that misfolded proteins do not accumulate, which could otherwise lead to cellular dysfunction and disease.