Heat shock proteins
Heat shock proteins ( English heat shock protein, HSP ) are proteins that other proteins in the fold or in maintaining their secondary structure help under extreme conditions. They are formed to an increased extent after cells have been exposed to heat or other types of environmental stresses such as ultraviolet radiation , heavy metals or ethanol . In these situations of cellular stress, heat shock proteins stabilize cellular proteins in order to protect them from denaturation or accelerate the breakdown of no longer functional proteins via the proteasome .
In physiologically normal situations, the ubiquitous heat shock proteins play a more important role than chaperones , which are involved in the correct folding and maturation of proteins. These non-stress-induced heat shock proteins are also called Hsc (for heat shock cognates , English cognate 'related' ). According to their molecular mass , heat shock proteins are divided into the families of small heat shock proteins (e.g. Hsp27 with a mass of 27 kDa ), Hsp40 , Hsp60 (chaperonins) and the Hsp70 / Hsp90 heat shock proteins. The various heat shock protein families are not related to one another in terms of function, structure or genetics, but there are significant homologies within one family . They can also be functionally different between different organisms.
literature
- JD Hasday, IS Singh: Fever and the heat shock response. Distinct, partially overlapping processes . In: Cell Stress Chaperones . tape 5 , no. 5 , 2000, pp. 471-480 , PMID 11189454 (English).
- Pramod K. Srivastava : With heat shock proteins against cancer . In: Spectrum of Science . May 2009, ISSN 0170-2971 , p. 40–46 ( excerpt from article ).
Web links
Individual evidence
- ^ B. Javid, et al .: Structure and Function. Heat Shock Proteins and Adaptive Immunity . In: The Journal of Immunology . tape 179 , 2007, pp. 2035-2040 (English, jimmunol.org ).