tailieunhanh - Báo cáo khoa học: The heat shock factor family and adaptation to proteotoxic stress

The heat shock response was originally characterized as the induction of a set of major heat shock proteins encoded by heat shock genes. Because heat shock proteins act as molecular chaperones that facilitate protein fold-ing and suppress protein aggregation, this response plays a major role in maintaining protein homeostasis. | ễFEBS Journal MINIREVIEW The heat shock factor family and adaptation to proteotoxic stress Mitsuaki Fujimoto and Akira Nakai Yamaguchi University Schoolof Medicine Ube Japan Keywords evolution heat shock protein homeostasis protein-misfolding disorder transcription factor vertebrate Correspondence Akira Nakai Department of Biochemistry and Molecular Biology Yamaguchi University Schoolof Medicine Minami-Kogushi 1-1-1 Ube 755-8505 Japan Fax 81 836 22 2315 Tel 81 836 22 2214 E-mail anakai@ Received 10 May 2010 revised 7 July 2010 accepted 23 July 2010 doi The heat shock response was originally characterized as the induction of a set of major heat shock proteins encoded by heat shock genes. Because heat shock proteins act as molecular chaperones that facilitate protein folding and suppress protein aggregation this response plays a major role in maintaining protein homeostasis. The heat shock response is regulated mainly at the level of transcription by heat shock factors HSFs in eukaryotes. HSF1 is a master regulator of the heat shock genes in mammalian cells as is HSF3 in avian cells. HSFs play a significant role in suppressing protein misfolding in cells and in ameliorating the progression of Caenor-habditis elegans Drosophila and mouse models of protein-misfolding disorders by inducing the expression of heat shock genes. Recently numerous HSF target genes were identified such as the classical heat shock genes and other heat-inducible genes called nonclassical heat shock genes in this study. Importance of the expression of the nonclassical heat shock genes was evidenced by the fact that mouse HSF3 and chicken HSF1 play a substantial role in the protection of cells from heat shock without inducing classical heat shock genes. Furthermore HSF2 and HSF4 as well as HSF1 shown to have roles in development were also revealed to be necessary for the expression of certain nonclassical heat shock genes. Thus the heat shock .