Amino-terminal acetylation of proteins in mammalian biology and disease

项目摘要 尽管科学界在阐明许多基因的功能方面取得了实质性进展， 还有很多未知的，特别是关于引入蛋白质的多样性， 翻译修饰一种这样的修饰是氨基末端乙酰化（NTA），其显著降低了氨基末端乙酰化的活性。 研究不足，很少有哺乳动物的N-末端的报告。蛋白质的乙酰化发生在赖氨酸 蛋白质内的残基（赖氨酸乙酰化或N-ε-乙酰化）和蛋白质N-末端的残基（N-乙酰化 或N-乙酰化）。蛋白质N-乙酰化是真核生物蛋白质最常见的修饰之一， 由N-末端乙酰转移酶（NAT）进行。细胞培养中人NAT的敲低表型 表明蛋白质NTA是人类细胞中维持增殖必需修饰，但是功能性的 缺乏深入的了解和哺乳动物体内模型。对NTA的一般作用的理解仍然是难以捉摸的， 只有少数几个NTA影响蛋白质功能、复合物形成、活性或稳定性的例子是已知的。 我的实验室发现并描述了第一种与N-末端乙酰化（NTA）相关的遗传疾病， 蛋白质，涉及X连锁基因NAA 10的错义突变;我们将这种罕见的疾病命名为Ogden 在家乡（奥格登，犹他州）的荣誉，在那里的第一个家庭，我们确定与OS生活。的 受影响的男孩有明显的颅面异常，张力减退，全面发育迟缓， 隐睾、心脏畸形和心脏肥大。我们和其他人随后找到了十几个家庭 在这一途径中，NAA 10的表型与其他突变重叠;我们最近还报道， 编码NAA 10结合伴侣的NAA 15的新生突变与先天性心脏病有关 和/或神经发育。这一发现与心脏异常的范围一致， 在OS中观察到的神经发育延迟（现在更广泛地称为NAA 10相关疾病）。作为我们 长期专注于NTA的机制解剖，在未来五年内，我们将专注于详细的 对通路中有突变的人进行表型分析，同时对独特的小鼠模型进行系统水平的研究， 包括条件等位基因，使用组织学和功能方法提供第一个机制的见解， NTA在心脏发育和哺乳动物生理学中的作用。我们还将继续分析 新发现的酶的途径，我们建议补偿和防止胚胎死亡， NAA 10突变的人类和小鼠模型。这一R35赠款将使分子的研究 与NAA 10和NAA 15相关疾病和NTA途径相关的生物学和病理生理学， 这是持续努力了解NTA在哺乳动物生物学中的作用的一部分。这些研究将是一个关键的 这是揭示NTA在人类健康和疾病中作用的一步，因为NTA与癌症有关 进展和神经退行性疾病，包括帕金森病、阿尔茨海默病和亨廷顿病。

PROJECT SUMMARY Although the scientific community has made substantial progress in elucidating the function of many genes, much remains unknown, particularly concerning the diversity introduced into proteins with co- and post- translational modifications. One such modification is amino-terminal acetylation (NTA), which is considerably understudied, with very few reports on the mammalian N-terminome. Protein acetylation occurs both at lysine residues within proteins (lysine acetylation or N-ε-acetylation) and at the N-terminus of proteins (Nt-acetylation or N--acetylation). Protein Nt-acetylation is among the most common modifications of eukaryotic proteins and is carried out by N-terminal acetyltransferases (NATs). The knockdown phenotypes of human NATs in cell culture suggest that protein NTA is an essential modification in human cells to maintain proliferation, but functional insights and mammalian in vivo models are lacking. Understanding of a general role for NTA remains elusive, and only a few examples in which NTA affects protein function, complex formation, activity, or stability are known. My laboratory discovered and characterized the first genetic disease coupled to N-terminal acetylation (NTA) of proteins, involving a missense mutation in the X-linked gene NAA10; we named this rare disease Ogden syndrome (OS) in honor of the hometown (Ogden, Utah), where the first family we identified with OS lived. The affected boys have a distinct combination of craniofacial anomalies, hypotonia, global developmental delays, cryptorchidism, cardiac anomalies, and cardiomegaly. We and others then found more than a dozen families with overlapping phenotypes with additional mutations in NAA10 in this pathway; we also reported recently that de novo mutations in NAA15, encoding a binding partner for NAA10, are involved in congenital heart defects and/or neurodevelopment. This finding is consistent with the range of cardiac anomalies and neurodevelopmental delays seen in OS (now more broadly known as NAA10-related disorders). As part of our long-term focus on the mechanistic dissection of NTA, over the next five years, we will focus on detailed phenotyping of humans with mutations in the pathway, alongside a systems-level study of unique mouse models, including conditional alleles, using histologic and functional approaches to provide the first mechanistic insights into the role of NTA in cardiac development and mammalian physiology. We will also continue our analysis of a newly identified enzyme in the pathway, which we propose compensates for and prevents embryonic lethality in humans and mouse models with mutations in NAA10. This R35 grant will enable the study of the molecular biology and pathophysiology associated with NAA10- and NAA15-related disorders and the NTA pathway, as part of a sustained effort to understand the role of NTA in mammalian biology. These studies will be a critical step toward revealing the role of NTA in human health and disease, as NTA has been linked to cancer progression and neurodegenerative diseases, including Parkinson’s, Alzheimer’s, and Huntington’s diseases.