The most important and most studied heat shock proteins
form the HSP70 gene family. They play essential roles in
protein metabolism under normal and stress conditions, including
de novo protein folding, membrane translocation,
degradation of misfolded proteins and other regulatory processes.
Their expression is regulated by environmental and
physiological stress and non-stressful conditions such as cell
growth, development and pathophysiological states [2]. While
their binding to an unfolded polypeptide chain results in the
stabilization of the unfolded state, their controlled release may
allow progression along the folding pathway [3]. Owing to
their functions, HSP70s have been included in the large family
of chaperones.
The regulation of expression of HSP70 genes occurs mainly