Transfer RNA-derived Small RNAs: Degradation Fragments or Novel Regulatory Molecules?*

Abstract

Transfer RNAs (tRNAs) with classic clover structure, have been researched as a key component of cellular protein synthesis machine for decades. However, the pace of progress in the understanding of tRNA function is still staggering, especially in the role of tRNA as the precursor of potential molecules to regulate gene expression globally. Several recent studies suggest that some tRNA-derived small RNAs have been detected in many cell lines by deep sequencing. These cleavage products of tRNAs are indicated to interact with some important protein factors like Dicer and Ago family in microRNA processing system. In additional, luciferase reporter assay results implied that the small RNAs derived from tRNA might play some roles in response to the stress as regulatory molecules with microRNA-like features. If their regulatory functions were to be confirmed by more evidence, these newly revealed RNAs would provide expanding insight into the repertoire of small noncoding RNAs.