ABSTRACT
When a cell experiences environmental stress, it stops, or at least slows down most of its original functions, such as transport processes, DNA, RNA and protein synthesis. However, there is a peculiar set of proteins, called stress proteins, which are preferentially expressed under these, restrictive conditions. The archetypal stress response is a sudden rise in the outside temperature, called heat shock. The heat shock response was first discovered by Feruccio Ritossa (1962), who observed an enlargement of special sections of Drosophila melanogaster chromosomes (heat shock puffs) after heat treatment of the flies. Later it became clear that these chromosome segments encoded a special
class of proteins, heat shock proteins. (Hsp-s) are induced by a large variety of stimuli besides heat shock itself. Table 6.1 lists a few examples of environmental stresses leading to the expression of heat shock, or other stress proteins.
