3tiRNA

3tiRNA, or 3′ tRNA-derived stress-induced RNA, refers to a class of small non-coding RNA fragments generated from the 3′ portion of mature transfer RNAs (tRNAs) in response to cellular stress. These fragments are produced alongside complementary 5′ tiRNAs by cleavage events in or near the anticodon loop, often mediated by stress-activated RNases such as angiogenin. 3tiRNAs are typically in the range of about 28 to 40 nucleotides and retain the 3′ end of the parental tRNA, with whether the CCA tail is preserved depending on the specific processing event.

The biogenesis of 3tiRNA is linked to cellular stress conditions, including oxidative stress and other insults that trigger tRNA cleavage. As a result, 3tiRNAs become part of a broader family of tRNA-derived fragments that are rapidly produced under stress and can persist long enough to influence cellular responses. Their precise sequences reflect their tRNA origin, contributing to their potential diversity across tissues and stress types.

Functionally, 3tiRNAs are implicated in the regulation of protein synthesis and stress response pathways. They can influence translation by interacting with components of the initiation machinery or ribosomal subunits and may promote or modulate the formation of stress granules, thereby affecting mRNA stability and translation during stress. The exact mechanisms and physiological roles of 3tiRNAs remain an active area of research, with ongoing studies exploring their relevance in cellular adaptation, disease contexts, and their potential as biomarkers.

Overall, 3tiRNA is part of the growing landscape of tRNA-derived fragments that participate in rapid cellular responses to stress, complementing other tiRNA classes and contributing to the complexity of post-transcriptional regulation.