HSF1 activation

Heat shock factor 1 (HSF1) is a transcription factor that activates gene expression in response to a variety of stresses, including heat shock, oxidative stress, as well as inflammation and infection (Shamovsky I and Nudler E 2008; Akerfelt et al. 2010; Bjork and Sistonen 2010; Anckar and Sistonen 2011).<p>HSF1 is constitutively present in the cell. In the absence of stress HSF1 is found in both the cytoplasm and the nucleus as an inactive monomer (Sarge KD et al. 1993; Mercier PA et al. 1999; Vujanac M et al. 2005). A physical or chemical proteotoxic stress rapidly induces HSF1 activation, which occurs through a multi?step process, involving HSF1 monomer-to-homotrimer transition, nuclear accumulation, and binding to a promoter element, called the heat shock element (HSE), which leads to the increase in the stress-inducible gene expression (Sarge KD et al. 1993; Baler R et al. 1998; Sonna LA et al. 2002; Shamovsky I and Nudler E 2008; Sakurai H and Enoki Y 2010; Herbomel G et al. 2013). Depending on the type of stress stimulus, the multiple events associated with HSF1 activation might be affected differently (Holmberg CI et al 2000; Bjork and Sistonen 2010).

热休克因子1（HSF1）作为一种转录因子，能够在细胞内响应多种应激状态，包括热应激、氧化应激，以及炎症和感染等（Shamovsky I 和 Nudler E 2008；Akerfelt 等人 2010；Bjork 和 Sistonen 2010；Anckar 和 Sistonen 2011）。HSF1在细胞中持续存在。在无应激状态下，HSF1以非活性单体形式存在于细胞质和细胞核中（Sarge KD 等人 1993；Mercier PA 等人 1999；Vujanac M 等人 2005）。物理或化学性的蛋白毒性应激能够迅速诱导HSF1的活化，这一过程涉及多步骤，包括HSF1单体向同源三聚体的转变、核积累以及与称为热休克元件（HSE）的启动子元件的结合，从而导致应激诱导的基因表达增加（Sarge KD 等人 1993；Baler R 等人 1998；Sonna LA 等人 2002；Shamovsky I 和 Nudler E 2008；Sakurai H 和 Enoki Y 2010；Herbomel G 等人 2013）。根据应激刺激的类型，与HSF1活化相关的多重事件可能受到不同的影响（Holmberg CI 等人 2000；Bjork 和 Sistonen 2010）。