eat shock proteins (HSPs), also called stress proteins, are not only
induced in response to elevated temperatures, but also as a result of
various stress situations, including environmental strains, viral H
infection, ischemia, anoxia and oxidative stress. These stress
situations trigger cellular defence mechanisms that act as an emergency
system capable of combatting the toxic consequences due to the
accumulation of misfolded proteins. Heat shock proteins are involved in
many physiological processes, including development and differentiation,
organisation of the cytoarchi tecture by binding to cytoskeletal
elements and regulation of the balance between cell death and survival.
Many heat shock proteins work as molecular chaperones. In this role,
they contribute to in vivo protein folding and prevent nonproductive
interactions with other proteins and cellular c- ponents. In recent
years it has been found that the chaperone system and the proteolytic
machinery work closely together, and that proteasomal - hibition causes
the upregulation of stress proteins. Impairment of the proteasomal
machinery and chaperone functions lead to protein damage, which
contributes to neurodegenerative disorders and to the aging process.