Investigate the Transcriptional Co-factors of DAF-16/FOXO in C. elegans

描述(申请人提供)：DAF-16/FOXO家族的转录因子是进化上保守的主调控因子，能够整合不同的环境刺激，协调发育、代谢、应激反应和寿命。众所周知，FOXO蛋白在癌症和糖尿病等与年龄相关的疾病中扮演着关键角色。DAF-16/FOXO要实现其多方面的核心作用，其转录活性需要受到精细的调控；然而，DAF-16/FOXO介导的基因转录调控的机制在很大程度上是未知的。这项建议的长期目标是全面阐明DAF-16/FOXO转录活动在细胞核中是如何调控的，以及这种调控如何有助于决定长寿。我们最近发现，线虫核蛋白宿主细胞因子1(HCF-1)的同源基因通过作为DAF-16辅助因子发挥作用，抑制DAF-16介导的基因调控而调节寿命。由于HCF-1是第一个在线虫中报道的DAF-16负相关因子，这一发现为进一步研究DAF-16转录活性是如何调节的提供了一个重要的切入点。在目标1中，我们建议检验这样一种假设，即DAF-16介导的转录输出的特异性由HCF-1和其他DAF-16共因子之间的相互作用决定。在目标2中，我们建议验证这样的假设，即HCF-1与SIR-2.1形成调控网络，以调节特定靶基因上的DAF-16转录活性。在目标3中，我们建议识别调节DAF-16介导的基因转录的额外转录因子和染色质因子。由于DAF-16及其辅助因子(HCF-1、SIR-2.1、SMK-1、BAR-1、CTBP-1)都是高度保守的，我们的研究结果将为哺乳动物FOXO的调控和寿命决定提供重要的见解。此外，DAF-16及其辅助因子在哺乳动物中的同源基因在许多人类疾病的发病机制中发挥着关键作用，如癌症和糖尿病，我们的研究结果可能会启发未来旨在缓解人类一些与年龄相关的病理的治疗开发。 与公共健康相关：DAF-16/FOXO家族的转录因子是高度保守的主调控因子，能够整合各种环境刺激，协调发育、新陈代谢、应激反应和寿命。这项应用建议使用强大的遗传模型线虫来研究几个高度保守的DAF-16辅助因子如何共同作用，以精确控制DAF-16介导的基因调控。这项提案的发现将与哺乳动物的FOXO调控直接相关，并将为衰老生物学提供重要的见解，并可能激励未来旨在长寿和缓解与年龄相关的疾病的治疗开发。

DESCRIPTION (provided by applicant): Transcription factors of the DAF-16/FOXO family are evolutionarily conserved master regulators capable of integrating diverse environmental stimuli and coordinating development, metabolism, stress responses, and longevity. Deregulation of FOXO proteins in humans is well known to play a key role in age- related diseases such as cancer and diabetes. For DAF-16/FOXOs to achieve their multi-faceted and central roles, their transcriptional activities need to be exquisitely regulated; however, the mechanisms underlying the regulation of DAF-16/FOXO-mediated gene transcription are largely unknown. The long-term goal of this proposal is to elucidate comprehensively how DAF-16/FOXO transcriptional activities are regulated in the nucleus and how this regulation contributes to longevity determination. We recently discovered that the C. elegans ortholog of the nuclear protein host cell factor 1 (HCF-1) modulates longevity by functioning as a DAF-16 co-factor that inhibits DAF-16-mediated gene regulation. Since HCF-1 is the first DAF-16 negative co-factor reported in C. elegans, this finding provides an important entry point for further investigation of how DAF-16 transcriptional activities are regulated. In Aim 1, we propose to test the hypothesis that the specificity of DAF-16-mediated transcriptional output is determined by the interplay between HCF-1 and other DAF-16 co-factors. In Aim 2, we propose to test the hypothesis that HCF-1 forms a regulatory network with SIR-2.1 to regulate DAF-16 transcriptional activity on specific target genes. In Aim 3, we propose to identify additional transcription and chromatin factors that regulate DAF-16-mediated gene transcription. Since DAF-16 and its co-factors (HCF-1, SIR-2.1, SMK-1, BAR-1, CTBP-1) are all highly conserved, findings from our studies will provide important insights into FOXO regulation and longevity determination in mammals. Moreover, the mammalian orthologs of DAF-16 and its co-factors are known to play key roles in the pathogenesis of a number of human diseases, such as cancer and diabetes, findings from our studies may inspire future therapeutic development aiming to alleviate some of these age-related pathologies in humans. PUBLIC HEALTH RELEVANCE: Transcription factors of the DAF-16/FOXO family are highly conserved master regulators capable of integrating diverse environmental stimuli and coordinating development, metabolism, stress responses, and longevity. This application proposes to use the powerful genetic model C. elegans to investigate how several highly conserved DAF-16 co-factors function together to precisely control DAF-16-mediated gene regulation. The findings from this proposal will have direct relevance to FOXO regulation in mammals and will provide important insights into the biology of aging, and may inspire future therapeutic development that aims to benefit longevity and alleviate age-related diseases.