Expanding the Genetic Code with Phosphoserine

含有遗传密码之外的氨基酸的蛋白质的合成最近作为一个令人感兴趣的话题重新浮出水面，在智力和技术上提出了巨大的挑战。对遗传密码进行重新编程需要两个关键事件：(I)创建一个新的高效的‘正交’氨酰基tRNA合成酶：tRNA对能够仅产生非规范的氨基酰基tRNA。(Ii)通过重新编码特定的信使核糖核酸密码子来确定该氨基酸将被插入蛋白质的位置的能力。基于最近发现的产甲烷氨酰合成酶样蛋白的自然存在，O-磷酸丝氨酸tRNA合成酶及其同源tRNACys的研究将以信使RNA中无意义的密码子UAG为基础，建立一个将磷酸丝氨酸共翻译插入多肽中预定位置的原核和真核系统。鉴于磷酸丝氨酸在真核细胞中对细胞增殖、细胞信号转导和细胞死亡至关重要的重要性，一种强有力的方法来制备含有磷丝氨酸的蛋白质将具有广泛的应用和重要的意义。该项目将为本科生和博士后提供跨学科的培训。

Synthesis of proteins containing amino acids outside of the genetic code has recently resurfaced as a topic of much interest and presents a great challenge intellectually and technically. Reprogramming the genetic code requires two key events: (i) The creation of a new efficient 'orthogonal' aminoacyl tRNA synthetase:tRNA pair able to generate solely a non canonical aminoacyl tRNA. (ii) The ability to specify the position in which this amino acid will be inserted in the protein by recoding a particular mRNA codon. Based on the natural existence of the recently discovered methanogen aminoacylsynthetase like protein, O-phosphoseryl tRNA synthetase and its cognate tRNACys research will be initiated to develop a prokaryotic and a eukaryotic system for the cotranslational insertion of phosphoserine at pre determined positions in a polypeptide based on the nonsense codon UAG in a messenger RNA. Given the importance of phosphoserine in eukaryotic proteins essential for cell proliferation, cellular signaling, and cell death, a robust method of making phosphoserine containing proteins will have wide application and great significance. This project will provide interdisciplinary training for undergraduate and postdoctoral students.