Spastic paraplegia, neurodegeneration and autism: possible role for AT-1/SLC33A1?

痉挛性截瘫、神经退行性变和自闭症：AT-1/SLC33A1 的可能作用？

基本信息

批准号：
9144474
负责人：
Luigi Puglielli
金额：
$ 33.1万
依托单位：
UNIVERSITY OF WISCONSIN-MADISON
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-09-20 至 2020-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9144474
关键词：
Acetyl Coenzyme A Acetylation Acetyltransferase Affect Animals Area Autistic Disorder Autophagocytosis Behavioral Biochemical Biochemistry Biological Biology Biomedical Research Cell Nucleus Cell physiology Cessation of life Collaborations Cytoplasm Cytosol Data Databases Defect Development Developmental Delay Disorders Disease Endoplasmic Reticulum Event Functional disorder Generations Genes Grant Human Immune system In Vitro Infection Inflammatory Response Intellectual functioning disability Knock-in Mouse Laboratories Left Lysine Magnetic Resonance Malignant Neoplasms Mass Spectrum Analysis Membrane Membrane Transport Proteins Modeling Molecular Mus Mutation Nerve Degeneration Nervous system structure Neuraxis Neurons Organelles Pathology Pathway interactions Patients Peripheral Phenotype Physiological Physiology Post-Translational Protein Processing Proteins Reaction Regulation Reporting Research Role Signal Transduction Spastic Paraplegia Stream Structure Testing Transgenic Mice autism spectrum disorder base disease phenotype human disease in vivo meetings motor deficit mouse model nervous system disorder novel novel therapeutic intervention overexpression polypeptide premature protein expression protein transport public health relevance response sensor trafficking

项目摘要

DESCRIPTION (provided by applicant): Nε-lysine acetylation is an essential post-translational modification. It regulates activity, molecular stabilization and conformational assembly of targeted proteins. For more than forty years it was assumed that lysine acetylation could only occur in the cytosol and nucleus. However, in 2007, we reported the transient lysine acetylation of endoplasmic reticulum (ER) cargo proteins. Subsequent studies revealed that the ER has two acetyltransferases (ATase1 and ATase2) as well as a membrane transporter (AT-1/SCL33A1) that translocates acetyl-CoA, donor of the acetyl group for the reaction of acetylation, into the ER lumen. AT- 1/SCL33A1 is essential for the intraluminal acetylation of ER-resident and -transiting proteins. Changes in acetyl-CoA influx affect the acetylation status of the ER. Heterozygous mutations in AT-1/SCL33A1 have been identified in patients affected by a familial form of spastic paraplegia while homozygous mutations have been identified in patients affected by developmental delay of the nervous system and premature death. Finally, a duplication of AT-1/SCL33A1 has been reported in patients with autism spectrum disorder and intellectual disability. The general hypothesis of our research is that tight regulation of acetyl-CoA influx ino the ER lumen by AT-1 is essential for neuron biology. To test the above hypothesis we have generated mouse models of reduced (AT-1S113R/+) and increased (AT-1 Tg) acetyl-CoA influx into the ER. AT-1S113R/+ mice develop deficits of both the immune and nervous system. The defects of the immune system result in increased propensity to infections, aberrant inflammatory response, and increased propensity to malignancies. The defects of the nervous system result into severe motor deficits and degenerative features of the peripheral (PNS) and central (CNS) nervous system. AT-1 Tg mice display an autistic-like phenotype with behavioral deficits, impaired LTP and LTD, and increased neuronal branching. The data collected so far suggests that the ER-based acetylation machinery regulates the efficiency of protein trafficking along the secretory pathway and the induction of ERAD(II). Specific Aim 1 will test the hypothesis that the S113R (associated with spastic paraplegia) and A110P (associated with developmental delay) mutations affect the structure of AT-1 and block post-translational assembly of the transporter in the ER membrane. Specific Aim 2 will test the hypothesis that Atg9A acts as a "sensor" of acetyl-CoA levels in the ER lumen and regulates induction of ERAD(II)/autophagy down-stream of AT-1. Together, Aim 1 and Aim 2 will dissect the molecular basis of diseases associated with deficient ER acetylation. Specific Aim 3 will test the hypothesis that abnormally high influx of acetyl-CoA into the ER lumen in AT-1 Tg mice increases the efficiency of the secretory pathway beyond physiological requirements and causes broad changes on protein expression levels in the neuron. This Aim will dissect the molecular basis of the autism spectrum disorder and intellectual disability associated with the duplication of AT-1/SCL33A1.

描述（由申请人提供）：Nε-赖氨酸乙酰化是一种重要的翻译后修饰，它调节靶蛋白的活性、分子稳定性和构象组装，四十多年来，人们一直认为赖氨酸乙酰化只能发生在细胞质中。然而，2007 年，我们报道了内质网 (ER) 货物蛋白的瞬时赖氨酸乙酰化。 ER 具有两种乙酰转移酶（ATase1 和 ATase2）以及一种膜转运蛋白 (AT-1/SCL33A1)，可将乙酰辅酶 A（乙酰化反应的乙酰基供体）转移到 ER 腔中。对于 ER 驻留蛋白和转运蛋白的腔内乙酰化至关重要。乙酰辅酶 A 流入影响 ER 的乙酰化状态，在患有家族性痉挛性截瘫的患者中发现了 AT-1/SCL33A1 的杂合突变，而在受神经系统发育迟缓影响的患者中发现了纯合突变。最后，在患有自闭症谱系障碍和智力障碍的患者中发现了 AT-1/SCL33A1 的重复。我们研究的总体假设是。 AT-1 对乙酰辅酶 A 流入内质网腔的严格调节对于神经元生物学至关重要，为了检验上述假设，我们构建了乙酰基减少 (AT-1S113R/+) 和乙酰基增加 (AT-1 Tg) 的小鼠模型。 -CoA 流入 AT-1S113R/+ 小鼠会出现免疫和神经系统缺陷。免疫系统缺陷导致感染倾向增加。异常的炎症反应和增加的恶性肿瘤倾向导致严重的运动缺陷和周围（PNS）和中枢（CNS）神经系统的退化特征，AT-1 Tg 小鼠表现出类似自闭症的表型。行为缺陷、LTP 和 LTD 受损以及神经元分支增加迄今为止收集的数据表明，基于 ER 的乙酰化机制调节沿分泌途径的蛋白质运输和诱导。 ERAD(II)。具体目标 1 将检验以下假设：S113R（与痉挛性截瘫相关）和 A110P（与发育迟缓相关）突变影响 AT-1 的结构并阻止 ER 膜中转运蛋白的翻译后组装。具体目标 2 将测试 Atg9A 作为 ER 腔中乙酰辅酶 A 水平的“传感器”并调节诱导的假设AT-1 下游的 ERAD(II)/自噬。目标 1 和目标 2 将共同剖析与 ER 乙酰化缺陷相关的疾病的分子基础。具体目标 3 将检验乙酰辅酶 A 异常大量流入的假设。 AT-1 Tg 小鼠的 ER 腔提高了超出生理需求的分泌途径的效率，并导致神经元中蛋白质表达水平的广泛变化。剖析与 AT-1/SCL33A1 重复相关的自闭症谱系障碍和智力障碍的分子基础。