Protein CASC3 (CASC3)

Core part of the splicing-dependent multiprotein exon junction complex (EJC) deposited at splice junctions on mRNAs. The EJC is a dynamic structure consisting of core proteins and several peripheral nuclear and cytoplasmic related things that join the complicated only transiently either through EJC assembly or through subsequent mRNA metabolism.

The EJC marks the place of the exon-exon intersection at the mature mRNA for the gene expression machinery and the core elements stay bound to spliced mRNAs through all stages of mRNA metabolism thereby influencing downstream processes including nuclear mRNA export, subcellular mRNA localization, translation efficiency and nonsense-mediated mRNA decay (NMD). Stimulates the ATPase and RNA- helicase activities of EIF4A3.