tRNA 37位6-苏氨酰氨基甲酰腺苷酸修饰及其生物学功能

Biological function of N^6-threonylcarbamoyladenosine modification at position 37 of tRNA

转运RNA(transfer RNA,t RNA)上存在着大量的转录后核苷酸修饰,其参与并调控t RNA的生物学功能。t RNA 37位6-苏氨酰氨基甲酰腺苷酸(N^6-threonylcarbamoyladenosine,t^6A)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t RNA。越来越多的研究表明,t^6A参与调控t RNA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-t^6A、2-甲硫基-t^6A、环形t^6A、2-甲硫基环形t^6A及羟基t^6A等t^6A的衍生形式。开展tRNA上t^6A修饰的研究,将丰富人们对t^6A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t^6A修饰和其衍生形式及其参与tRNA功能调控的分子机制。

t RNAs contain numerous post-transcriptional nucleotide modifications, regulating the biological function of t RNAs. The N^6-threonylcarbamoyladenosine（t^6 A） modification is conserved at position 37 of t RNAs in bacteria, archaea and eukaryotes. Accumulating data suggested that the t^6 A modification regulates the binding of t RNA anticodon with m RNA codon, efficiency of m RNA translation, binding of t RNA with ribosome and cells growth. In addition, there are other derivatives of t^6 A such as cyclic t^6 A, 6-methyl-t^6 A, 2-methylthio-t^6 A, 2-methylthio-cyclic t^6 A and hydroxy-t^6 A. The study on t^6 A modification in t RNAs 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 t^6 A modification and its derivatives and their regulatory mechanisms for the function of t RNAs.