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Updated: Jul 15, 2026

Analysis of Spliceosomal snRNA Localization in Human Hela Cells Using Microinjection
Published on: August 6, 2019
U1, U2, and U4/U6 small nuclear ribonucleoproteins are required for in vitro splicing but not polyadenylation
Abstract:
The requirement for individual U RNAs in splicing and polyadenylation was investigated using oligonucleotide-directed cleavage of snRNAs in in vitro processing extracts. Cleavage of U1, U2, or U4 RNA inhibited splicing but not polyadenylation of short precursor RNAs. Thus each snRNA and the snRNP in which it is assembled participates in the splicing reaction. Splicing activity was recovered when extracts containing cleaved U RNAs were mixed in pairwise combinations, indicating that U1, U2, and U4/U6 snRNPs independently interact with the assembling spliceosome. The involvement of multiple snRNPs in the splicing of simple precursor RNAs suggests that the spliceosome is a large complex assembly consisting of multiple snRNPs whose activity is dependent on the structural integrity of the individual U RNAs.
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