Regulation of Heat Shock Transcription Factor in Long-lived Animals

描述(由申请人提供)：延长寿命通常与增强对环境和生理压力的有害影响的抵抗力有关，包括热和氧化压力。我们以前的结果表明，线虫热休克转录因子(HSF-1)是细胞对热应激反应的主要调节因子，它受到胰岛素/IGF-1样信号(IIS)网络的直接调节，以调节衰老的速度和与蛋白毒性相关的衰老相关疾病的发生。我们研究的最终目标是通过了解HSF-1如何影响衰老过程来开发新的治疗策略来对抗与年龄相关的疾病。我们以前已经证明，衰老速度可以受到线虫中HSF-1活性水平的影响，并且HSF-1活性是daf-2突变延长寿命所必需的。我们最近的研究结果表明，IIS可能通过调节含有HSF-1、HSB-1和两个新的HSF-1调节因子DDL-1和-2的抑制性蛋白异源复合体(DHIC)的形成来控制HSF-1的活性。我们发现，当IIS被还原或当DDL-1在T182残基被磷酸化时，DHIC的形成在很大程度上被抑制。我们还发现，DDL-1的磷酸化状态受IIS的调节。基于这些观察，这项建议将集中在：1)进一步确定DHIC复合体在HSF-1调控中的作用。为此，我们将开发一个BIFC报告系统来验证DHIC在体内的形成，并将其用作读出以确定DHIC形成的其他调控因子。我们还将确定DHIC复合体形成的结构要求。2)确定IIS调节DDL-1磷酸化和DHIC形成的机制。在拟议的研究中，我们将确定IIS途径如何调节DDL-1的磷酸化和DHIC的形成。3)鉴定和鉴定HSF-1的其他调节因子和效应子。热休克和IIS的减少都促进了HSF-1翻译后修饰(PTM)的增加。为此，我们将研究这些PTM对HSF-1活性的影响。此外，我们还将进一步鉴定以前从基因筛查中发现的一些新的HSF-1调节因子。

DESCRIPTION (provided by applicant): Extended longevity is often correlated with increased resistance against the deleterious effects of environmental and physiological stresses, including heat and oxidative stresses. Our previous results suggested that the C. elegans heat-shock transcription factor (HSF-1), a master regulator of the cellular response to heat stress, is under direct regulation of the insulin/IGF-1-like signaling (IIS) networks to modulate the rate of aging and the onset of age-related diseases associated with proteotoxicity. The ultimate goal of our research is to develop new therapeutic strategies for combating age-related disease by understanding how HSF-1 influences the aging process. We have previously demonstrated that the rate of aging can be influenced by the level of HSF-1 activity in C. elegans, and that HSF-1 activity is required for daf-2 mutations to extend lifespan. Our recent findings suggest that IIS may control HSF-1 activity by regulating the formation of an inhibitory protein heterocomplex (DHIC) containing HSF-1, HSB-1, and two novel HSF-1 regulators, DDL-1 and -2. We found that the formation of DHIC is largely inhibited when IIS is reduced or when DDL-1 is phosphorylated at the T182 residue. We also found that the phosphorylation status of DDL-1 is regulated by IIS. Based on these observations, this proposal will focus on: 1) Further defining the role of DHIC complex in HSF-1 regulation. In this aim, we will develop a BiFC reporting system to verify the formation of DHIC in vivo and use it as a read-out to identify additional regulators of DHIC formation. We will also determine the structural requirements for the DHIC complex formation. 2) Determining the mechanism by which IIS regulates DDL-1 phosphorylation and DHIC formation. In the proposed studies, we will determine how the IIS pathway regulates DDL-1 phosphorylation and the formation of DHIC. 3) Identifying and characterizing additional regulators and effectors of HSF-1. Both heat-shock and reduction of IIS promotes an increase in the post- translational modifications (PTM) of HSF-1. In this aim, we will investigate the impacts of these PTMs on HSF- 1 activity. In addition, we will further characterize a number of novel HSF-1 regulators previously identified from a genetic screen.