catalytic activity:Endonucleolytic cleavage of pre-tRNA, producing 5'-hydroxy and 2',3'-cyclic phosphate termini, and specifically removing the intron.,disease:Defects in TSEN2 are the cause of pontocerebellar hypoplasia type 2B (PCH2B) [MIM:612389]. Pontocerebellar hypoplasia (PCH) is a heterogeneous group of disorders characterized by an abnormally small cerebellum and brainstem. PCH type 2 is characterized by progressive microcephaly from birth combined with extrapyramidal dyskinesia and chorea, epilepsy, and normal spinal cord findings.,function:Constitutes one of the two 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. Isoform 1 probably carries the active site for 5'-splice site cleavage. 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. The complex containing isoform 2 is not able to cleave pre-tRNAs properly, although it retains endonucleolytic activity, suggesting that isoform 2 complex is responsible for processing as yet unknown RNA substrate.,PTM:Phosphorylated upon DNA damage, probably by ATM or ATR.,similarity:Belongs to the tRNA-intron endonuclease family.,subcellular location:May be transiently localized in the nucleolus.,subunit:tRNA splicing endonuclease is a heterotetramer composed of isoform 1 of SEN2, SEN15, SEN34/LENG5 and SEN54. tRNA splicing endonuclease complex also contains proteins of the pre-mRNA 3'-end processing machinery such as CLP1, CPSF1, CPSF4 and CSTF2. Isoform 2 belongs to a different complex that contains SEN54 but low level of SEN15 and SEN34/LENG5.,tissue specificity:Isoform1 and isoform 2 are widely expressed at very low level.,
Nucleus . Nucleus, nucleolus . May be transiently localized in the nucleolus.
Isoform 1 and isoform 2 are widely expressed at very low level.