Polypyrimidine Tract-Binding ProteinRNA-Binding ProteinsRibonucleoproteinsHeterogeneous-Nuclear RibonucleoproteinsRNA PrecursorsAlternative SplicingHeterogeneous-Nuclear Ribonucleoprotein Group F-HRNA SplicingExonsEncephalomyocarditis virusIntronsHeLa CellsTropomyosinMolecular Sequence DataBase Sequence5' Untranslated RegionsProtein BindingRNA, MessengerBinding SitesRibosomesNucleic Acid ConformationProtein BiosynthesisGene Expression RegulationDNA-Binding ProteinsCell NucleusCell LineAmino Acid SequenceNuclear ProteinsRNA Splice SitesPyrimidinesMutationSpliceosomesHeterogeneous-Nuclear Ribonucleoprotein Group CRNA, Viral