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Heat‐induced expression of the immediate‐early gene IER 5 and its involvement in the proliferation of heat‐shocked cells
Author(s) -
Ishikawa Yukio,
Sakurai Hiroshi
Publication year - 2015
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/febs.13134
Subject(s) - heat shock protein , heat shock factor , chaperone (clinical) , hsf1 , microbiology and biotechnology , gene expression , gene , hsp70 , biology , chemistry , downregulation and upregulation , biochemistry , medicine , pathology
The serum‐inducible and growth factor‐inducible gene IER 5 encodes a protein that acts as a regulator of cell proliferation. Expression of IER 5 is also induced by treatment of cells with ionizing radiation and anticancer agents. In this study, we demonstrate the expression and function of IER 5 in heat‐shocked cells. Heat treatment causes robust expression of IER 5 in a heat shock factor ( HSF )1‐dependent manner. HSF 1 is the master transcriptional regulator of chaperone genes, and the IER 5 promoter contains the binding sequence for HSF 1 and is bound by heat‐activated HSF 1. Proteotoxic stressors, such as celastrol and MG 132, are known to activate HSF 1, and are potent inducers of HSF 1 binding and IER 5 expression. Overexpression of IER 5 leads to upregulation of chaperone gene expression and to an increase in refolding of heat‐denatured proteins. Cells expressing IER 5 efficiently recover viability after heat challenge. These observations suggest that HSF 1‐mediated IER 5 expression is involved in the expression of chaperone genes and in recovery from thermal stress.