Heat Shock Factor mediates actin phosphorylation in tissue integrity and age

热休克因子介导组织完整性和年龄的肌动蛋白磷酸化

• 批准号: 9902289
• 负责人: Peter Mahan Douglas
• 金额: $ 33.21万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-04-01 至 2024-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9902289
• 关键词: Actins; Adult; Age; Aging; Animals; Apical; Architecture; Base Sequence; Binding; Binding Sites; Biochemical; Biological Assay; Caenorhabditis elegans; Cells; Complex; Data; Defect; Digestion; Dyes; Elasticity; Epithelial; Epithelium; Escherichia coli; Exclusion; Functional disorder; Genes; Genetic; Genetic Epistasis; Genetic Transcription; Goals; HSF1; Heat shock factor; Impairment; In Vitro; Intercellular Junctions; Internet; Intestines; Laboratories; Link; Longevity; Maintenance; Mediating; Methods; Microfilaments; Mitogen-Activated Protein Kinases; Molecular; Motor; Myosin ATPase; Nematoda; Organ; Permeability; Phosphorylation; Phosphotransferases; Photobleaching; Physiological; Physiology; Play; Post-Translational Protein Processing; Process; Proteins; RNA Interference; Recovery; Regulation; Relaxation; Research; Role; Serine; Stress; Structure; Surface; System; Tensile Strength; Testing; Time; Tissues; Troponin; Troponin I; Untranslated Regions; Variant; age related; body system; cellular microvillus; experimental study; ferrofluid; gene repression; heat shock transcription factor; in vivo; inorganic phosphate; intestinal barrier; intestinal epithelium; jun Oncogene; mimetics; physical property; reconstitution; resilience; vesicle transport

Project Summary/Abstract Aging involves the gradual decay of tissues, organs and organ systems. Early in this process, impermeability or selective permeability of tissues deteriorates and gives rise to increasing organ dysfunction. This phenomenon has been termed barrier dysfunction, yet the molecular mechanisms, which drive tissue “leakiness” and contribute to organ aging are unclear. To interrogate the underlying mechanism, we examine the aging intestine of the nematode, C. elegans, to determine how resiliency of the intestinal barrier withstands the test of time. Preliminary screens from my lab have linked age regulation by the Heat Shock transcription Factor, HSF-1, with the activity of the intestine-specific actin protein, ACT-5. Although expressed in a small number of cells and comprising less than 2% of total worm actin, ACT-5 plays an essential role in intestinal and organismal aging. Through the proposed five-year research period, we aim to understand how age-related decline in HSF-1 activity contributes to tissue dysfunction and animal aging. In particular, we will characterize the molecular mechanism of age progression in which HSF-1 dysregulation impairs cellular architecture and intestinal physiology. We speculate that age-associated decline in HSF-1 activity impairs specialized actin networks in intestinal epithelium, which ultimately compromise vesicular traffic, cell-cell junctional integrity and tissue barrier maintenance. We have already identified the stress-activated JUN kinase, KGB-1, as a repressed transcriptional target of HSF-1, which catalyzes phosphate addition to the ACT-5 protein within its binding site for the actin filament stabilizing Troponin complex. Accumulation of phosphorylated ACT-5 at serine residue 232 dramatically influences the structural integrity of the apical terminal web and vesicular transport across it. Overall, the proposed research will uncover a phosphorylation-dependent actin relaxation mechanism under HSF-1 control, which facilitates vesicular transport across dense, actin-rich “roadblocks” while still maintaining their structural rigidity and cellular architecture.

项目摘要/摘要 衰老涉及组织，器官和器官系统的等级衰减。在此过程的早期，不理性或 组织检测性的选择性渗透性，并导致器官功能障碍增加。这个现象 已称为障碍功能障碍，但分子机制使组织“泄漏”和 有助于器官衰老尚不清楚。为了询问潜在的机制，我们检查了老化的肠 线虫，秀丽隐杆线虫的纪念碑，以确定肠壁屏障的弹性如何承受时间的测试。 我实验室的初步屏幕通过热激转录因子HSF-1与年龄调节有关， 肠特异性肌动蛋白的活性，ACT-5。虽然在少数细胞中表达，并且 ACT-5占蠕虫总肌动蛋白的不到2％，在肠道和有机衰老中起着至关重要的作用。 在拟议的五年研究期间，我们旨在了解与年龄相关的HSF-1活动下降 有助于组织功能障碍和动物衰老。特别是，我们将表征分子机制 HSF-1失调会损害细胞结构和肠道生理的年龄进步。我们 推测与年龄相关的HSF-1活性下降会损害肠道中的专业肌动蛋白网络 上皮最终损害了囊泡交通，细胞 - 细胞连接完整性和组织屏障 维护。我们已经将应力激活的Jun激酶KGB-1确定为复制的转录 HSF-1的靶标，该靶标会在其肌动蛋白的结合位点催化磷酸盐添加到ACT-5蛋白 细丝稳定肌钙蛋白复合物。丝氨酸居住区磷酸化ACT-5的积累232急剧 影响顶端终端网的结构完整性和横跨囊泡的囊泡运输。总体而言， 拟议的研究将发现在HSF-1控制下的磷酸化依赖性肌动蛋白松弛机制， 这有助于横跨密集，富含肌动蛋白的“障碍”的囊泡运输，同时仍保持其结构 刚性和蜂窝结构。