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.
Involvement in disease
Defects in TSEN54 are the cause of pontocerebellar hypoplasia type 4 (PCH4) [MIM:225753]. Pontocerebellar hypoplasia (PCH) is a heterogeneous group of disorders characterized by an abnormally small cerebellum and brainstem. PCH4 is characterized by severe course and early lethality. Defects in TSEN54 are the cause of pontocerebellar hypoplasia type 2A (PCH2A) [MIM:277470]. 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.
Belongs to the SEN54 family.
Phosphorylated upon DNA damage, probably by ATM or ATR.
Nucleus. Nucleus > nucleolus. May be transiently localized in the nucleolus.