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？

• 批准号: 10518395
• 负责人: Luigi Puglielli
• 金额: $ 44.6万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-20 至 2025-11-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10518395
• 关键词: Acetyl Coenzyme A; Acetylation; Acetyltransferase; Affect; Animals; Area; Autophagocytosis; Biochemical; Biochemical Pathway; Biochemistry; Biological; Biological Process; Biology; Biomedical Research; Brain; Cell membrane; Citrates; Complement; Cytosol; DNA Sequence Alteration; Databases; Defect; Developmental Delay Disorders; Disease; Embryo; Encephalopathies; Endoplasmic Reticulum; Equilibrium; Event; Funding; Gene Duplication; Generations; Genetic; Glutamate-ammonia-ligase adenylyltransferase; HSPB1 gene; Hereditary Sensory and Autonomic Neuropathies; Heterozygote; Individual; Inherited; Intellectual functioning disability; Laboratories; Longevity; Lysine; Mass Spectrum Analysis; Membrane Transport Proteins; Metabolic; Metabolic Pathway; Modeling; Molecular; Mus; Mutation; Nerve Degeneration; Neurodegenerative Disorders; Neurodevelopmental Disorder; Neurons; Nonsense Codon; Outcome; Paper; Pathway interactions; Phenotype; Play; Progeria; Proteins; Proteome; Publishing; Quality Control; Reporting; Research; Role; Spastic Paraplegia; Testing; Therapeutic; Transgenic Mice; autism spectrum disorder; citrate carrier; disease phenotype; epileptic encephalopathies; human disease; loss of function; mitochondrial membrane; mouse model; novel; overexpression; prevent; proteostasis

We discovered that Nε-lysine acetylation occurs in the lumen of the endoplasmic reticulum (ER) in 2007. From that initial finding, we went on to discover the entire ER acetylation machinery (one membrane transporter, AT-1/SLC33A1, and two acetyltranferases, ATase1 and ATase2) and uncover a novel piece of ER biology. Specifically, we discovered that the ER acetylation machinery regulates proteostasis within the ER and secretory pathway by maintaining the balance between quality control/engagement of the secretory pathway and reticulophagy. By using a combination of biochemistry and high-definition mass spectrometry, we discovered that SLC25A1 and SLC13A5 act as important “metabolic partners” of AT-1. Homozygous mutations in AT-1/SLC33A1, SLC25A1 or SLC13A5 are associated with developmental delay of the brain and early forms of encephalopathy while heterozygous mutations are associated with similar forms of hereditary sensory and autonomic neuropathies (HSANs), including specific forms of spastic paraplegias. Important, these mutations either introduce a premature STOP codon or cause loss-of-function of the transporters. Furthermore, gene duplication events of AT-1/SLC33A1, SLC25A1 or SLC13A5 are associated with autism spectrum disorder (ASD), intellectual disability, and progeria-like dysmorphism. To expand our studies, we generated neuron-specific (AT-1 nTg, SLC25A1 nTg, and SLC13A5 nTg) and systemic (AT-1 sTg, SLC25A1 sTg, and SLC13A5 sTg) overexpressing mice. These animals display important phenotypic similarities, supporting the conclusion that we have identified a unified metabolic pathway that is at the basis of closely related neurodegenerative and neurodevelopmental diseases across lifespan. To complement the above studies and dissect the specific role of the two ATases, down-stream of AT-1, we have also generated Atase1-/- and Atase2-/- mice. Their phenotype supports the idea that these two ER-based acetyltransferases have evolved to play partially divergent roles. The GENERAL HYPOTHESIS of this research is that SLC25A1, SLC13A5, and AT-1 act in concert to regulate engagement of the secretory pathway and induction of reticulophagy. Specific Aim 1 will test the hypothesis that the ER acetylation machinery is the downstream target of a dysfunctional cytosol-to-ER flux of acetyl-CoA caused by the duplication of AT-1, SLC25A1 or SLC13A5. Specific Aim 2 will use our newly generated Atase1-/- and Atase2-/- mice to test the hypothesis that ATase1 and ATase2 have partially different biological functions. Specific Aim 3 will test the hypothesis that specific structural features of newly identified AT-1 downstream targets allow fine tuning of reticulophagy. In conclusion, this proposal is the result of novel discoveries made in our laboratory; it will help us dissect the molecular mechanisms of severe neurodegenerative and neurodevelopmental diseases across lifespan and it will allow us dissect essential molecular and biochemical functions of the ER that will impact other areas of biomedical research.

我们发现Nε-赖氨酸乙酰化发生在2007年内质网（ER）的腔内。 从最初的发现，我们继续发现了整个ER乙酰化机制（一个膜） 转运蛋白，AT-1/SLC33A1和两个乙酰脱甲酶，ATASE1和ATASE2），并发现了一块新颖的一块 ER生物学。具体而言，我们发现ER乙酰化机制调节ER内的蛋白质量 通过保持分泌质量控制/参与之间的平衡来保持秘密途径 途径和网状噬菌体。通过结合生物化学和高清质谱法，我们 发现SLC25A1和SLC13A5是AT-1的重要“代谢伴侣”。 AT-1/SLC33A1，SLC25A1或SLC13A5中的纯合突变与发育延迟有关 脑病的大脑和早期形式，而杂合突变与类似形式相关 遗传性感觉和自主神经病（HSAS），包括特定形式的痉挛性截瘫。 重要的是，这些突变要么引入过早的终止密码子，要么引起造成功能的丧失 运输商。此外，AT-1/SLC33A1，SLC25A1或SLC13A5的基因重复事件相关 自闭症谱系障碍（ASD），肠道残疾和促进性畸形。扩大我们的 研究，我们产生了神经元特异性（AT-1 NTG，SLC25A1 NTG和SLC13A5 NTG）和全身性（AT-1 STG， SLC25A1 STG和SLC13A5 STG）过表达小鼠。这些动物表现出重要的表型 相似性，支持以下结论：我们已经确定了一个统一的代谢途径 跨越生命周期密切相关的神经退行性和神经发育疾病。完成 以上研究并剖析了两个Atases的特定作用，即AT-1的下游，我们还产生了 ATASE1 - / - 和ATASE2 - / - 小鼠。它们的表型支持这两个基于ER的乙酰基转移酶的想法 已经演变为扮演部分不同的角色。这项研究的总体假设是Slc25a1， SLC13A5和AT-1协同行动，以规范秘密途径的参与和归纳 网状噬菌体。特定目标1将检验ER乙酰化机制是下游的假设 由AT-1，SLC25A1或 SLC13A5。具体目标2将使用我们新生成的ATASE1 - / - 和ATASE2 - / - 小鼠来测试以下假设。 ATASE1和ATASE2具有部分不同的生物学功能。具体目标3将检验以下假设 新确定的AT-1下游目标的特定结构特征允许对网状噬菌体进行微调。在 结论，该提议是我们实验室中新发现的结果。它将帮助我们剖析 生命周期的严重神经退行性和神经发育疾病的分子机制，IT 将使我们剖析ER的基本分子和生化功能，这些功能将影响其他领域 生物医学研究。