Final answer:
HSP-90 facilitates protein folding by inducing conformational changes in the proteins. It is part of a cellular response to stress, such as high temperatures, and ensures proteins maintain their functional three-dimensional structure. HSP-70 similarly aids in protein translocation and refolding within different cellular compartments.
Step-by-step explanation:
HSP-90 aids in protein folding by inducing conformational changes rather than causing direct peptide bond formation, catalyzing DNA replication, or inhibiting protein synthesis. Heat shock proteins like HSP-90 and HSP-70 are known as molecular chaperones and play a critical role in the cellular response to stressors such as high temperatures, changes in pH, and the presence of certain chemicals. HSP-90 is particularly intriguing because it stabilizes and refolds proteins, ensuring they achieve their proper three-dimensional structure which is vital for their function. This protective mechanism is important as it helps cells survive during periods of thermal stress by preventing the accumulation of misfolded proteins that can disrupt cellular function. Moreover, heat shock proteins can help with the transport and refolding of proteins across cellular membranes, acting in concert with signal peptidases and other chaperones. For instance, HSP-70 plays an integral role in aiding the entry and proper folding of mitochondrial proteins.