Meta-Biol

• Pathways

DHX8 (homolog of yeast Prp22) hydrolyzes ATP and translocates along the RNA in a 3' to 5' direction (Felisberto-Rodrigues et al. 2019) to release the spliced mRNA and associated proteins (Merz et al. 2007), including the exon junction complex (EJC), from the Spliceosomal P complex (Ohno and Shimura 1996, Zhang et al. 2019). After the second splicing reaction, DHX8 interacts with CACTIN and SRRM2 in the Spliceosomal P complex and is bound to the 3' exon downstream of the 3' splice site. As DHX8 translocates along the RNA, it is thought to pull the 3' end of the spliced exon and dissociate the spliced exon from the U5 snRNA. SLU7 and PRPF18 are also dissociated from the spliceosome at this time. The intron lariat remains bound to the intron lariat spliceosome (ILS) (Yoshimoto et al. 2009). TFIP11 (homolog of yeast Ntr1) is present in the ILS (Yoshimoto et al. 2009) and recruits DDX15 (homolog of yeast Prp43) to disassemble the ILS.