Figure 1. Cellular responses to stress and environmental factors.

Stresses such as heat shock are sensed by factors located inside of or outside of the cell (1). In the case of HSF1, it relays the message to the nucleus (2) to strongly increase the transcription of genes involved in fixing protein shape (3). RNA stability (4) and protein production levels (5) are also important factors determining the response to stress. Protein activity (6), such as the chaperones induced by heat shock, is critical in mediating the response. In higher eukaryotes, cells may send signals (7) to neighboring cells to assist in mounting a larger stress response encompassing many cells and tissues.