Fan Chenguang, Ip Kevan, Söll Dieter
Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR, USA.
Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA.
FEBS Lett. 2016 Sep;590(17):3040-7. doi: 10.1002/1873-3468.12333. Epub 2016 Aug 11.
Protein phosphorylation is one of the most important post-translational modifications in nature. However, the site-specific incorporation of O-phosphotyrosine into proteins in vivo has not yet been reported. Endogenous phosphatases present in cells can dephosphorylate phosphotyrosine as a free amino acid or as a protein residue. Therefore, we deleted the genes of five phosphatases from the genome of Escherichia coli with the aim of stabilizing phosphotyrosine. Together with an engineered aminoacyl-tRNA synthetase (derived from Methanocaldococcus jannaschii tyrosyl-tRNA synthetase) and an elongation factor Tu variant, we were able to cotranslationally incorporate O-phosphotyrosine into the superfolder green fluorescent protein at a desired position in vivo. This system will facilitate future studies of tyrosine phosphorylation.
蛋白质磷酸化是自然界中最重要的翻译后修饰之一。然而，体内将O-磷酸酪氨酸位点特异性掺入蛋白质的情况尚未见报道。细胞内存在的内源性磷酸酶可将磷酸酪氨酸作为游离氨基酸或蛋白质残基进行去磷酸化。因此，我们从大肠杆菌基因组中删除了五种磷酸酶的基因，目的是稳定磷酸酪氨酸。结合一种工程化的氨酰-tRNA合成酶（源自嗜热栖热菌酪氨酸-tRNA合成酶）和一种延伸因子Tu变体，我们能够在体内将O-磷酸酪氨酸共翻译掺入到超折叠绿色荧光蛋白的期望位置。该系统将促进未来对酪氨酸磷酸化的研究。
