How Cells Respond to Stress; May 1993; Scientific American Magazine; by William J. Welch; 8 Page(s)

Immediately after a sudden increase in temperature, all cells--from the simplest bacterium to the most highly differentiated neuron--increase production of a certain class of molecules that buffer them from harm. When biologists first observed that phenomenon 30 years ago, they called it the heatshock response. Subsequent studies revealed that the same response takes place when cells are subjected to a wide variety of other environmental assaults, including toxic metals, alcohols and many metabolic poisons. It occurs in traumatized cells growing in culture, in the tissues of feverish children and in the organs of heart-attack victims and cancer patients receiving chemotherapy. Because so many different stimuli elicit the same cellular defense mechanism, researchers now commonly refer to it as the stress response and to the expressed molecules as stress proteins.

In their pursuit of the structure and function of the stress proteins, biologists have learned that they are far more than just defensive molecules. Throughout the life of a cell, many of these proteins participate in essential metabolic processes, including the pathways by which all other cellular proteins are synthesized and assembled. Some stress proteins appear to orchestrate the activities of molecules that regulate cell growth and differentiation.