an ubiquitous RNA-binding protein. Component of a splicing-dependent multiprotein exon junction complex (EJC) deposited at splice junction on mRNAs. The EJC is a dynamic structure consisting of a few core proteins and several more peripheral nuclear and cytoplasmic associated factors that join the complex only transiently either during EJC assembly or during subsequent mRNA metabolism. The EJC is composed of ACIN1, CASC3, DDX48, MAGOH, PNN, RBM8A, RNPS1, SAP18 and THOC4. Forms heterodimers with RNPS1. Found in a heterotrimeric complex with ACIN1, RNPS1 and SAP18. Interacts with API5. Phosphorylation by SRPK2 redistributes it from the nuclear speckles to the nucleoplasm, and up-regulates its stimulatory effect on cyclin A1. Activated by proteolytic cleavage. Induces apoptotic chromatin condensation after activation by CASP3. Regulates cyclin A1, but not cyclin A2, expression in leukemia cells. Four alternatively spliced human isoforms have been described. Note: This description may include information from UniProtKB.
Protein type: Apoptosis; RNA splicing; RNA-binding; Spliceosome