PROTEIN FUNCTIONS IN PRE-MESSENGER-RNA SPLICING

Proteins have been implicated in an expanding variety of functions dur ing pre-mRNA splicing. Molecular cloning has identified genes encoding spliceosomal proteins that potentially act as novel RNA helicases, GT Pases, or protein isomerases. Novel protein-protein and protein-RNA in teractions that are required for functional spliceosome formation have also been described. Finally, growing evidence suggests that proteins may contribute directly to the spliceosome's active sites.