Biochemical and functional investigation of the novel enzymatic activities of MESH1

MESH1 新型酶活性的生化和功能研究

• 批准号: 10237887
• 负责人: Jen-Tsan Ashley Chi
• 金额: $ 39.13万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-15 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10237887
• 关键词: Address; Affect; Amino Acids; Anabolism; Bacteria; Biochemical; Biochemistry; Biological Process; Calcium; Calcium Signaling; Cardiac Myocytes; Catalysis; Cell Proliferation; Cell Survival; Cells; Cystine; Data; Estrogen receptor positive; Estrogens; Excision; Exposure to; Gene Expression; Genetic; Genetic Transcription; Genome; Homeostasis; Homologous Gene; Human; Hydrolase; Investigation; Isoproterenol; Knowledge; Ligase; Mammalian Cell; Mediating; Metabolic; Metabolic stress; Minority; Modeling; Mus; Myocardial Ischemia; NAADP; NADH; NADP; Nutrient; Organism; Oxidative Stress; Permeability; Phenotype; Phosphoric Monoester Hydrolases; Public Health; Reaction; Regulation; Reperfusion Injury; Role; Spottings; Stimulus; Stress; Structure; Sulfate; Therapeutic; X-Ray Crystallography; biological adaptation to stress; cofactor; environmental stressor; estrogen sulfate; human disease; in vitro activity; novel; overexpression; receptor; release of sequestered calcium ion into cytoplasm; response

The main strategy for bacteria to cope with metabolic stresses is through the stringent response triggered by the accumulation of the alarmone (p)ppGpp. While metazoan genomes also encode a homologue of the (p)ppGpp hydrolase SpoT (MESH1), neither a homologue of the (p)ppGpp synthetase nor (p)ppGpp itself has been found in metazoa. Therefore, the stringent response was thought to be absent in metazoa. Unexpectedly, we found that the silencing of MESH1 in mammalian cells triggered a cellular response highly similar to the bacterial stringent response. Such a response is characterized by the short-term stress survival, reversible proliferation arrest as well as extensive transcriptional and metabolic reprogramming. As (p)ppGpp is not found in metazoa, we hypothesize that Mesh1 mediates the novel cellular response by mechanisms independent of (p)ppGpp. In this proposal, we will investigate the biochemistry of the novel enzymatic activities of MESH1 and establish their functional contributions to the mammalian cells’ response to various stresses and stimuli. The successful execution of the proposed studies will help elucidate how the novel enzymatic activities of MESH1—the mammalian orthologue of the bacterial (p)ppGpp hydrolase—contribute to its biological function in mediating the mammalian cellular response to various stresses and stimuli and realize its therapeutic potential in human diseases.

细菌应对新陈代谢压力的主要策略是通过警报(P)ppGpp的积累引发的严格反应。虽然后生动物基因组也编码(P)ppGpp水解酶Spot(MESH1)的同源基因，但在后生动物中既没有发现(P)ppGpp合成酶的同源基因，也没有发现(P)ppGpp本身。因此，后生动物没有严格的反应。出乎意料的是，我们发现哺乳动物细胞中MESH1的沉默引发了与细菌严格反应非常相似的细胞反应。这种反应的特征是短期的应激生存、可逆的增殖停止以及广泛的转录和代谢重新编程。由于在后生动物中没有发现(P)ppGpp，我们假设Mesh1通过独立于(P)ppGpp的机制来介导新的细胞反应。在这个计划中，我们将研究MESH1新的酶活性的生物化学，并建立它们在哺乳动物细胞对各种压力和刺激的反应中的功能贡献。这些研究的成功将有助于阐明MESH1-细菌(P)ppGpp水解酶的哺乳动物同源酶-的新的酶活性如何有助于其在介导哺乳动物细胞对各种应激和刺激的反应中的生物学功能，并实现其在人类疾病中的治疗潜力。