Mechanism of degradation of the proteasome through autophagy

通过自噬降解蛋白酶体的机制

• 批准号: 9899258
• 负责人: Jeroen Roelofs
• 金额: $ 30.6万
• 依托单位: UNIVERSITY OF KANSAS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-05-01 至 2022-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9899258
• 关键词: Active Sites; Aging; Animal Model; Autophagocytosis; Autophagosome; Biochemical; Biological; Biological Assay; Biological Process; Bortezomib; Cell Cycle Regulation; Cell Nucleus; Cell physiology; Cells; Complex; Cytosol; Data; Dependence; Deubiquitinating Enzyme; Dissociation; Ensure; Enzymes; Estrogen receptor positive; Eukaryota; Eukaryotic Cell; Excision; FDA approved; Future; Genetic Screening; Genetic Transcription; Goals; Half-Life; Health; Human; Hydrolase; Knowledge; Lead; Link; Lysosomes; Malignant Neoplasms; Mammalian Cell; Mantle Cell Lymphoma; Membrane; Modification; Molecular; Multiple Myeloma; Neurodegenerative Disorders; Nitrogen; Nuclear; Nuclear Export; Nucleosome Core Particle; Nutrient; Organelles; Outcome; Oxidative Stress; Pathway interactions; Peptide Hydrolases; Pharmaceutical Preparations; Physiological; Plants; Play; Post-Translational Protein Processing; Process; Proteasome Inhibitor; Proteins; Quality Control; Regulation; Research; Role; Shapes; Signal Pathway; Signal Transduction; Signal Transduction Pathway; Starvation; Stress; System; Techniques; Testing; Therapeutic; Time; Transcriptional Regulation; Ubiquitin; Vacuole; Yeasts; base; cancer cell; fitness; fluorescence microscope; human disease; improved; insight; multicatalytic endopeptidase complex; particle; polypeptide; protein aggregation; public health relevance; receptor; response; screening; yeast genetics

 DESCRIPTION (provided by applicant): Two cellular components, the lysosome (vacuole in yeast and plants) and the proteasome degrade the majority of proteins in eukaryotic cells. They display a partial overlap in substrates and crosstalk between them has been observed. Therefore, to understand the cells ability to degrade proteins it is important to know how the cellular level of the proteasome is controlled. While transcriptional regulation of proteasomes has been studied in yeast and mammalian cells, little is known concerning the mechanism or physiological conditions that target proteasomes for degradation. Reducing proteasome levels through degradation can impact many cellular processes and increase a cell's sensitivity to drugs. This can be therapeutically relevant, because cells can become more sensitive to proteasome inhibitors, like the FDA approved drugs Bortezomib and Carfizomib used in the treatment of multiple myelomas and mantle cell lymphomas. The objective of the research proposed here is to elucidate at the molecular level the signal pathways and biological processes that lead to the degradation of proteasomes by using biochemical and cell biological assays. Since many proteasome related processes are highly conserved amongst eukaryotes and little is known about this process, yeast will be used as a model organism. This will provide a wider array of techniques and screening abilities to determine the basic mechanism involved. Based on our preliminary data, two distinct processes are proposed to lead to proteasome degradation. Aim 1 will determine how overall proteasome levels are reduced upon nitrogen starvation. The goal is to identify proteins, post- translational modifications, and other signals involved in the process of nuclear export and autophagic packaging upon nitrogen starvation. Aim 2 will test the hypothesis that proteasomes that fail quality control are specifically removed via autophagy. The goal is to determine how factors that recognize faulty proteasomes link these complexes to the autophagy pathway that targets them for lysosomal degradation. The expected outcomes from these aims are the identification and a molecular understanding of the process that leads to targeting of proteasomes for autophagy. Understanding of these pathways will be important for future characterization of the impact these processes have on conditions that are relevant for human health. This can include conditions like nutrient starved cancer cells, increased oxidative stress, aging, or neurodegenerative diseases, which all have been shown to be impacted by the ubiquitin- proteasome system.

 描述(申请人提供)：两种细胞成分，溶酶体(酵母和植物中的液泡)和蛋白酶体能降解真核细胞中的大部分蛋白质。它们在衬底上显示出部分重叠，并观察到它们之间的串扰。因此，要了解细胞降解蛋白质的能力，重要的是要知道蛋白酶体的细胞水平是如何控制的。虽然在酵母和哺乳动物细胞中对蛋白酶体的转录调控进行了研究，但对以蛋白酶体为目标进行降解的机制或生理条件知之甚少。通过降解降低蛋白酶体水平可能会影响许多细胞过程，并增加细胞对药物的敏感性。这可能具有治疗意义，因为细胞可以对蛋白酶体抑制剂更加敏感，比如FDA批准的治疗多发性骨髓瘤和套细胞淋巴瘤的药物Bortezomib和Carfizomib。本研究的目的是通过生物化学和细胞生物学方法，在分子水平上阐明导致蛋白酶体降解的信号通路和生物学过程。由于许多与蛋白酶体相关的过程在真核生物中高度保守，而对这一过程知之甚少，酵母将被用作模式生物。这将提供更广泛的技术和筛选能力来确定所涉及的基本机制。基于我们的初步数据，我们提出了两个不同的过程来导致蛋白酶体的降解。目标1将确定在氮饥饿时整体蛋白酶体水平是如何降低的。目标是确定氮饥饿时核出口和自噬包装过程中涉及的蛋白质、翻译后修饰和其他信号。Aim 2将测试这样一种假设，即没有通过质量控制的蛋白酶体是通过自噬特异性移除的。目标是确定识别有缺陷的蛋白酶体的因子如何将这些复合体与以它们为目标的溶酶体降解的自噬途径联系起来。这些目标的预期结果是鉴定和分子理解导致自噬靶向蛋白酶体的过程。对这些途径的了解对于今后确定这些过程对与人类健康相关的条件的影响至关重要。这可能包括营养匮乏的癌细胞等情况， 氧化应激增加、衰老或神经退行性疾病，这些都已被证明受到泛素-蛋白酶体系统的影响。

项目成果

Proteasome Shuttle Factors Regulate the Relocalization of Proteasomes to Cytosolic Granules upon Specific Stress Conditions.

蛋白酶体穿梭因子在特定应激条件下调节蛋白酶体重新定位到胞质颗粒。

• 发表时间: 2022
• 期刊: FASEB journal : official publication of the Federation of American Societies for Experimental Biology
• 作者: Roelofs,Jeroen;Vontz,Gabrielle;Waite,KenrickA;Lee,StellaY
• 通讯作者: Lee,StellaY