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A factor, U2AF, is required for U2 snRNP binding and splicing complex assembly.

B Ruskin·P D Zamore·M R Green
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Abstract

Pre-mRNA splicing complex assembly is mediated by two specific pre-mRNA-snRNP interactions: U1 snRNP binds to the 5' splice site and U2 snRNP binds to the branch point. Here we show that unlike a purified U1 snRNP, which can bind to a 5' splice site, a partially purified U2 snRNP cannot interact with its target pre-mRNA sequence. We identify a previously uncharacterized activity, U2AF, that is required for the U2 snRNP-branch point interaction and splicing complex formation. Using RNA substrate exclusion and competition assays, we demonstrate that U2AF binds to the 3' splice site region prior to the U2 snRNP-branch point interaction. This provides an explanation for the necessity of the 3' splice site region in U2 snRNP binding and, hence, the first step of splicing.

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Binding SitesCarrier ProteinsCentrifugation, Density GradientChemical FractionationHeLa CellsHeterogeneous-Nuclear RibonucleoproteinsHumansImmunosorbent TechniquesMicrococcal NucleaseOsmolar ConcentrationPotassium ChlorideRNA PrecursorsRNA SplicingRNA, MessengerRNA-Binding ProteinsRibonucleoproteinsRibonucleoproteins, Small NuclearComparative StudyJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, P.H.S.

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B Ruskin, P D Zamore, M R Green. 1988-01-29. A factor, U2AF, is required for U2 snRNP binding and splicing complex assembly.. https://doi.org/10.1016/0092-8674(88)90509-0

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