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Heat-shock protein

Heat-shock proteins (otherwise known as HSPs or stress proteins) are created when cells are exposed to elevated temperatures, or to other kinds of environmental stress, such as ethanol, ultraviolet light, trace metals[?], or oxygen deprivation. They are present in all cells, in all life forms, appearing when the cell is under heat stress (or other stress). However, they are also present in cells under non-stressful conditions, simply "monitoring" the cell's proteins. Some examples of their role as "monitors" are that they carry old proteins to the cell's "recycling bin" and they help newly synthesised proteins fold properly. These activities are part of a cell's own repair system, called the "cellular stress response" or the "heat-shock response." The function of heat-shock proteins is similar in virtually all living organisms, from bacteria to humans.

Heat-shock proteins are of potential interest to cancer researchers, based on research that has shown that animals may respond to cancer "vaccinations." Tumor cells were "attenuated" (or weakened) and injected in small quantities into a rodent, causing the rodent to become immune to future full-fledged tumor-cell injections. While any relevance of animal research to humans has not been established, it is possible that the same may hold true for other species. Many years after this research was done, Pramod Srivastava[?] discovered that the specific part of the cell that was protecting the "immune" mice was the heat-shock proteins.

Scientists have not discovered exactly how heat-shock (or other environmental stressors) activates the heat-shock factor. However, some studies suggest that an increase in damaged or abnormal proteins bring HSPs into action.

Susan Lindquist is currently a leading heat-shock protein researcher. She is investigating, among other things, "how hsps are regulated, and how they function to protect organisms from death and from developmental anomalies induced by heat." - from her faculty page at: http://ben-may.bsd.uchicago.edu/CCB/faculty/lindquist

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