heat shock protein

In biochemistry, a protein that a cell produces in large amounts after a sudden rise in temperature. Many heat shock proteins act as molecular chaperones. They are part of the wider family of stress proteins, which also includes proteins produced in response to cold, pressure, and various chemical stress conditions.

The heat shock response was first discovered in 1962 as an anomaly in the chromosomes of fruit flies. In the 1970s, researchers found that this phenomenon, which could be induced by heat or certain chemicals, is accompanied by the synthesis of a small number of new proteins, which are often referred to by the letters HSP followed by a number indicating their approximate molecular mass in kilodalton, for example HSP70. These proteins were later found to be present in all organisms, but their functions remained elusive until the 1980s, when the concept of molecular chaperones developed.

Medical researchers are investigating potential uses of heat shock proteins against a range of disorders, including cancer, ischaemia, and Alzheimerseverals. They are also an important part of adjuvants, medications given with immunizations in order to enhance the immune response.

Beyond the chaperone role that most HSPs share, HSP90 was found to serve as a ‘capacitor’ that can suppress the effects of mutations over generations and release them in times of environmental stress, allowing a population to try out different variants in response to changes in the environment.