Tachibana Tomohusa, Astumi Shiho, Shioda Ryo, Ueno Masaru, Uritani Masahiro, Ushimaru Takashi
Department of Biology and Geoscience, Faculty of Science, Shizuoka University, Shizuoka 422-8529, Japan.
J Biol Chem. 2002 Jun 21;277(25):22140-6. doi: 10.1074/jbc.M201267200. Epub 2002 Apr 8.
The heat shock factor (HSF) is a pivotal transcriptional factor that regulates the expression of genes encoding heat shock proteins (HSPs) via heat shock elements (HSEs). nGAAnnTTCnnGAAn functions as the minimum consensus HSE (cHSE) in vivo. Here we show that the expression of Saccharomyces cerevisiae MDJ1 encoding a mitochondrial DnaJ homolog is regulated by HSF via a novel non-consensus HSE (ncHSE(MDJ1)), which consists of three separated pentameric nGAAn motifs, nTTCn-(11 bp)-nGAAn-(5 bp)-nGAAn. This is the first evidence to show that the immediate contact of nGAAn motifs is dispensable for regulation by HSF in vivo. ncHSE(MDJ1) confers different heat shock responses versus cHSE and, unlike cHSE, definitively requires a carboxyl-terminal activation domain of HSF in the expression. ncHSE(MDJ1)-like elements are found in promoter regions of some other DnaJ-related genes. The highly conserved HSF/HSE system suggests that similar ncHSEs may be used for the expression of HSP genes in other eukaryotes including humans.
热休克因子（HSF）是一种关键的转录因子，它通过热休克元件（HSE）调节编码热休克蛋白（HSP）的基因的表达。nGAAnnTTCnnGAAn在体内作为最小共有HSE（cHSE）发挥作用。在此，我们表明，酿酒酵母中编码线粒体DnaJ同源物的MDJ1的表达受HSF通过一种新型非共有HSE（ncHSE(MDJ1)）调控，该非共有HSE由三个分开的五聚体nGAAn基序组成，即nTTCn-(11个碱基对)-nGAAn-(5个碱基对)-nGAAn。这是首个表明nGAAn基序的直接接触对于HSF在体内的调控并非必需的证据。ncHSE(MDJ1)与cHSE赋予不同的热休克反应，并且与cHSE不同，在表达中明确需要HSF的羧基末端激活结构域。在一些其他与DnaJ相关的基因的启动子区域发现了类似ncHSE(MDJ1)的元件。高度保守的HSF/HSE系统表明，类似的ncHSEs可能用于包括人类在内的其他真核生物中HSP基因的表达。
