IBMPFD MUTATIONS IMPAIR UPS FUNCTION

IBMPFD 突变损害 UPS 功能

基本信息

批准号：
8403414
负责人：
CONRAD C WEIHL
金额：
$ 28.02万
依托单位：
WASHINGTON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-01-01 至 2013-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8403414
关键词：
26S proteasome ATP Hydrolysis ATP phosphohydrolase Address Affect Age Age-Months Aging Alzheimer&apos s Disease Amyloid Animal Model Animals Binding Biochemical Brain Cell Culture Techniques Cell model Cells Characteristics Data Defect Dementia Disease Dominant-Negative Mutation Endoplasmic Reticulum Frontotemporal Dementia Functional disorder Image Inclusion Bodies Inclusion Body Myositis Integral Membrane Protein Kinetics Life Link Mediating Minor Modeling Mus Muscle Muscle Weakness Mutation Myoblasts Myopathy N-terminal Neurodegenerative Disorders Osteitis Deformans Pathology Patients Phenotype Property Protein Family Proteins Rare Diseases Reporter Role Skeletal Muscle Sporadic Inclusion Body Myopathy Structure Syndrome System Time Tissues Transfer Factor Transgenic Animals Ubiquitin Vacuole age related effective therapy gain of function in vivo loss of function multicatalytic endopeptidase complex mutant normal aging novel p97-VCP protein protein complex protein degradation small hairpin RNA tau-1

项目摘要

Inclusion body myopathies (IBM) are disabling skeletal muscle disorders and considered a prototypical age related muscle disease. There is no effective treatment. IBM muscle has characteristic "rimmed vacuoles" and eosinophilic inclusions. These structures contain ubiquitinated and undegraded insoluble proteins that include ss-amyloid and phosphorylated tau; proteins that accumulate in Alzheimer's Disease brains. This overlapping pathology suggests a common pathogenic mechanism between IBM and neurodegenerative disorders. This link is strengthened further by the identification of mutations in the protein p97/VCP that cause the autosomal dominant syndrome, IBMPFD, IBM associated with paget's disease of the bone and frontotemporal dementia (FTD). p97/VCP is essential for the degradation of cytosolic derived proteasome substrates as well as for endoplasmic reticulum associated degradation of misfolded secreted or transmembrane proteins. It performs this role by selectively binding with ubiquitinated substrates via co-factors and transferring them to the 26S proteasome machinery. Currently it is unclear how mutations in p97/VCP cause disease. IBMPFD brain and muscle contains ubiquitinated protein inclusions. Our studies demonstrate that IBMPFD mutant p97/VCP leads to an increase in ubiquitinated proteins in cells. Skeletal muscle expression of IBMPFD mutant p97/VCP in mice causes an increase in ubiquitinated proteins as early as 30 days of life before weakness and myopathic changes which occur after 6 months of age. We propose to (1) study the biochemical properties of IBMPFD mutant p97/VCP with regard to structure, enzymatic activity and substrate binding. We will also (2) evaluate the effect of IBMPFD mutant p97/VCP on the ubiquitin-proteasome system (UPS) in cell culture and transgenic animals. These studies will use in vivo bioluminescent imaging of UPS function in skeletal muscle from living animals. Finally (3) we will compare the results obtained above with two complementary loss of p97/VCP function models. Although a rare disorder, the study of IBMPFD is essential to understand the role of the UPS in normal aging and aging related disorders such as sIBM and FTD.

包涵体肌病 (IBM) 是一种致残性骨骼肌疾病，被认为是一种典型的与年龄相关的肌肉疾病。没有有效的治疗方法。 IBM肌肉有特征性的“边缘空泡”和嗜酸性包涵体。这些结构包含泛素化和未降解的不溶性蛋白质，包括 ss-淀粉样蛋白和磷酸化 tau 蛋白；阿尔茨海默病大脑中积累的蛋白质。这种重叠的病理学表明 IBM 和神经退行性疾病之间的共同致病机制。这个链接是蛋白质 p97/VCP 中的突变的鉴定进一步加强了这一点，这些突变导致常染色体显性遗传综合征、IBMPFD、IBM 与佩吉特骨病相关额颞叶痴呆（FTD）。 p97/VCP 对于胞质来源的降解至关重要蛋白酶体底物以及内质网相关的降解错误折叠的分泌蛋白或跨膜蛋白。它通过选择性地结合来发挥这一作用通过辅因子泛素化底物并将其转移至 26S 蛋白酶体机器。目前尚不清楚 p97/VCP 突变如何导致疾病。 IBMPFD 大脑和肌肉含有泛素化蛋白质内含物。我们的研究表明 IBMPFD 突变体 p97/VCP 导致细胞中泛素化蛋白的增加。骨骼肌表达 IBMPFD 突变体 p97/VCP 在小鼠体内引起早在 30 岁时泛素化蛋白的增加 6 个月后出现无力和肌病变化之前的生命天数。我们建议 (1) 研究 IBMPFD 突变体 p97/VCP 的生化特性结构、酶活性和底物结合。我们还将 (2) 评估以下效果： IBMPFD 突变体 p97/VCP 对细胞培养中泛素蛋白酶体系统 (UPS) 的影响转基因动物。这些研究将使用 UPS 功能的体内生物发光成像来自活体动物的骨骼肌。最后（3）我们将上面得到的结果与 p97/VCP 功能模型的两个互补损失。尽管这是一种罕见的疾病，但研究 IBMPFD 对于理解 UPS 在正常老化和老化相关中的作用至关重要 sIBM 和 FTD 等疾病。