Rujuan Liu, PhDAssociate Professor

RNA molecules play a key role in all cellular processes. Chemical modifications expand RNA molecules from containing the standard four nucleotides Adenosine, Guanosine,   Uridine and Cytidine to more than 130 modified nucleotides, which increase   the complexity and flexibility of RNAs.In cells, transfer RNAs (tRNAs) are the heaviest modified RNA molecules. TRNA   is the key molecule in the “adaptor hypothesis “proposed by Fransis Crick, its most classical function is involved in protein synthesis to ensure the decoding of genetic information. Although this core role of tRNAs has been identified for several decades, many fundamental questions remain to be answered in the tRNA field, such as the function and meaning of the existence of more than 100 different chemical modifications on tRNAs, and the mechanism of occurrences and regulation of these dynamic modifications. Furthermore, many tRNA and tRNA derived RNA fragments have been found to function as   regulatory RNA, which play roles beyond protein translation in many physiological and pathological processes. What’s the role of chemical modifications on the coordination between the classical and nonclassical functions of tRNA? The defects of tRNA modifications and mutations of some tRNA   modification enzymes are directly associated with various human diseases especially neurological development/degeneration diseases and metabolic disorders, however,  little is known about the tRNA modification mechanism, and how modification  defects lead to human diseases. Our lab is focus on the molecular mechanisms and biological functions of dynamic tRNA modifications by using tRNA-seq, CLIP-seq, LC-MS/MS, enzymatic assays, and other technologies of biochemistry,   biophysics and cellular biology.