《生命科学》 2018, 30(4): 424-430
摘 要:摘 要:转运RNA (transfer RNA, tRNA) 上存在着大量的转录后核苷酸修饰,其参与并调控tRNA 的生物学功能。tRNA 37 位6-苏氨酰氨基甲酰腺苷酸(N6-threonylcarbamoyladenosine, t6A) 修饰是一类高度保守的转录后修饰,其广泛存在于古菌、细菌及真核生物tRNA。越来越多的研究表明,t6A 参与调控tRNA 反密码子与mRNA 密码子的结合、mRNA 翻译效率、tRNA 与核糖体的结合及细胞生长;同时,tRNA 上还存在6-甲基-t6A、2-甲硫基-t6A、环形t6A、2-甲硫基环形t6A 及羟基t6A 等t6A 的衍生形式。开展tRNA 上t6A 修饰的研究,将丰富人们对t6A 修饰的生物合成机制、生物学功能及在人类相关疾病中的潜在作用的认识。现将简要介绍已报道的t6A 修饰和其衍生形式及其参与tRNA 功能调控的分子机制。
Abstract: Abstract: tRNAs contain numerous post-transcriptional nucleotide modifications, regulating the biological function of tRNAs. The N6-threonylcarbamoyladenosine (t6A) modification is conserved at position 37 of tRNAs in bacteria, archaea and eukaryotes. Accumulating data suggested that the t6A modification regulates the binding of tRNA anticodon with mRNA codon, efficiency of mRNA translation, binding of tRNA with ribosome and cells growth. In addition, there are other derivatives of t6A such as cyclic t6A, 6-methyl-t6A, 2-methylthio-t6A, 2-methylthio-cyclic t6A and hydroxy-t6A. The study on t6A modification in tRNAs will provide us a deeper understanding for its biosynthesis mechanism, biological function and potential role in causing human diseases. Here, we briefly summarize the reported t6A modification and its derivatives and their regulatory mechanisms for the function of tRNAs.