Loco/RGS14 Signaling Pathway in Longevity

Loco/RGS14 信号通路与长寿

• 批准号: 8707608
• 负责人: YONGKYU PARK
• 金额: $ 23.43万
• 依托单位: RBHS-NEW JERSEY MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-06-01 至 2015-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8707608
• 关键词: Adenylate Cyclase; Affect; Aging; Aging-Related Process; Alzheimer' s Disease; Amino Acids; Apoptosis; Binding; Biological Models; Cell Nucleus; Cell Survival; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Data; Disease; Down-Regulation; Drosophila genus; Exhibits; Fatty acid glycerol esters; G-Protein Signaling Pathway; G-Protein-Coupled Receptors; GTP-Binding Protein Regulators; GTPase-Activating Proteins; Gel; Genes; Glucose; Guanine Nucleotide Exchange Factors; Guanosine Triphosphate; HRAS gene; Heating; Heterotrimeric G Protein Subunit; Heterotrimeric GTP-Binding Proteins; Homologous Gene; Insulin; Insulin-Like Growth Factor I; Ligands; Longevity; MAPKinase Signaling Pathway; MEKs; Mammals; Manganese; Molecular; Nucleotides; Nutrient; Organism; Outcome; Oxidative Stress; Pathway interactions; Phosphorylation; Phosphotransferases; Proteins; Proteomics; Publications; Publishing; RGS Domain; RGS Proteins; RGS2 gene; Ras/Raf; Rattus; Regulation; Reporting; Research; Resistance; Ribosomal Protein S6 Kinase; Signal Pathway; Signal Transduction; Sirolimus; Starvation; Stress; Superoxide Dismutase; System; Transcription Factor 3; Yeasts; age related; anti aging; base; dietary restriction; enzyme activity; fly; human HDAC1 protein; mutant; overexpression; oxidation; protein complex; scaffold; stressor

DESCRIPTION (provided by applicant): Although several conserved signaling pathways such as TOR-S6K, AC-PKA-Ras/Raf/MAPkinase, and IGF-1 are known to regulate stress resistance and longevity in various organisms, the mechanism of how RGS (regulator of G-protein signaling) protein affects aging process through G-protein signaling pathway is not understood yet. Our preliminary data exhibited that 1) reduced expression of a RGS protein, Loco, resulted in a longer lifespan of flies with stronger resistances to stressors, higher MnSOD activity, and increased fat contents. 2) In contrast, overexpression of the loco gene shortened lifespan significantly with lower stress resistance and reduced fat contents, also indicating that its RGS domain is related to the regulation of longevity. 3) Interestingly, expressional changes of yeast RGS2 and rat RGS14, homologues of the fly Loco, also affected oxidative stress resistance and longevity in the respective species, suggesting that Loco/RGS14 signaling pathway is evolutionarily conserved in various organisms for the regulation of longevity. It is known that Loco inactivates inhibitory G¿i¿GTP protein which reduces activity of adenylate cyclase (AC) and RGS14 interacts with activated H-Ras and Raf-1 kinases, which subsequently inhibits ERK phosphorylation. The specific hypothesis for this research is that Loco/RGS14 protein regulates stress resistance and longevity as an activator in AC-cAMP-PKA pathway and/or as a molecular scaffold that sequesters active Ras and Raf from Ras¿GTP-Raf-MEK-ERK signaling pathway. Consistently, our preliminary data showed that down-regulation of Loco significantly diminishes cAMP amounts and increases p-ERK levels with higher resistance to the oxidative stress. In addition, proteomic iTRAQ and 2D-gel analyses using loco mutant and overexpression revealed that Loco signaling increases phosphorylation levels of Rpd3 protein (HDAC1, histone deacetylase 1). Reduced expression of Rpd3 protein is reported to extend lifespan in Drosophila. However, it is not characterized how Rpd3/HDAC1 activity is regulated for longevity mechanism. Based on our preliminary data, the specific aims are to examine I) if Loco protein regulates the Ras/Raf/MAPkinase signaling pathway through direct interaction between them, II) if Loco/RGS14 signaling modulates phosphorylation levels of Rpd3/HDAC1 protein in both of fruitfly and mammal, III) if phosphorylation level of HDAC1 protein determines stress resistance and lifespan with regulating subcellular localization and/or activity of HDAC1 protein. Our approaches will find how the Loco/RGS14 protein regulates longevity with new and/or known longevity signaling pathway(s). We believe that the information obtained from our studies will advance our general understanding of the mechanisms of eukaryotic aging process and help us find ways to cure or delay aging-related diseases such as Alzheimer's disease.

描述（申请人提供）：虽然已知几种保守的信号通路如TOR-S6 K、AC-PKA-Ras/Raf/MAP激酶和IGF-1在各种生物体中调节应激抗性和寿命，但RGS（G蛋白信号调节因子）蛋白如何通过G蛋白信号通路影响衰老过程的机制尚不清楚。我们的初步数据表明，1）RGS蛋白，Loco的表达减少，导致果蝇寿命延长，对应激源的抗性更强，MnSOD活性更高，脂肪含量增加。2)与此相反，loco基因的过表达显著缩短了寿命，降低了应激抵抗力和脂肪含量，也表明其RGS结构域与寿命的调节有关。3)有趣的是，酵母RGS 2和大鼠RGS 14的表达变化，苍蝇位置的同源物，也影响氧化应激抗性和寿命在各自的物种，这表明位置/RGS 14信号通路是进化保守的在各种生物体中的寿命的调节。已知Loco使降低腺苷酸环化酶（AC）活性的抑制性G i i GTP蛋白失活，并且RGS 14与活化的H-Ras和Raf-1激酶相互作用，随后抑制ERK磷酸化。本研究的具体假设是Loco/RGS 14蛋白作为AC-cAMP-PKA通路中的激活剂和/或作为分子支架将活性Ras和Raf从Ras <$GTP-Raf-MEK-ERK信号通路中隔离，从而调节应激抗性和寿命。同样，我们的初步数据表明，下调Loco显著减少cAMP量，增加p-ERK水平，对氧化应激具有更高的抵抗力。此外，使用loco突变体和过表达的蛋白质组iTRAQ和2D凝胶分析显示，Loco信号传导增加了Rpd 3蛋白（HDAC 1，组蛋白脱乙酰酶1）的磷酸化水平。据报道，Rpd 3蛋白的表达减少可延长果蝇的寿命。然而，Rpd 3/HDAC 1活性如何调节长寿机制尚未得到表征。基于我们的初步数据，具体的目的是检查I）Loco蛋白是否通过它们之间的直接相互作用调节Ras/Raf/MAP激酶信号通路，II）Loco/RGS 14信号通路是否调节果蝇和哺乳动物中Rpd 3/HDAC 1蛋白的磷酸化水平，III）如果HDAC 1蛋白的磷酸化水平通过调节亚细胞定位来决定应激抗性和寿命，和/或或HDAC 1蛋白的活性。我们的方法将发现Loco/RGS 14蛋白如何通过新的和/或已知的长寿信号通路调节长寿。我们相信，从我们的研究中获得的信息将促进我们对真核生物衰老过程机制的全面理解，并帮助我们找到治疗或延缓老年痴呆症等衰老相关疾病的方法。