tRNA-splicing endonuclease subunit Sen15 is an enzyme that in humans is encoded by the TSEN15 gene.

tRNA splicing is a fundamental process required for cell growth and division. SEN15 is a subunit of the tRNA splicing endonuclease, which catalyzes the removal of introns, the first step in tRNA splicing (Paushkin et al., 2004 [PubMed 15109492]).[supplied by OMIM, Mar 2008].
Function: Non-catalytic subunit of the tRNA-splicing endonuclease complex, a complex responsible for identification and cleavage of the splice sites in pre-tRNA. It cleaves pre-tRNA at the 5' and 3' splice sites to release the intron. The products are an intron and two tRNA half-molecules bearing 2',3' cyclic phosphate and 5'-OH termini. There are no conserved sequences at the splice sites, but the intron is invariably located at the same site in the gene, placing the splice sites an invariant distance from the constant structural features of the tRNA body. The tRNA splicing endonuclease is also involved in mRNA processing via its association with pre-mRNA 3' end processing factors, establishing a link between pre-tRNA splicing and pre-mRNA 3' end formation, suggesting that the endonuclease subunits function in multiple RNA-processing events.