Dynamics and consequences of spliceosome E complex formation.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 28829039.
- Also identified by DOI 10.7554/eLife.27592 and PMC identifier 5779234.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The spliceosome must identify the correct splice sites (SS) and branchsite (BS) used during splicing. E complex is the earliest spliceosome precursor in which the 5' SS and BS are defined. Definition occurs by U1 small nuclear ribonucleoprotein (snRNP) binding the 5' SS and recognition of the BS by the E complex protein (ECP) branchpoint bridging protein (BBP). We have used single molecule fluorescence to study <i>Saccharomyces cerevisiae</i> U1 and BBP interactions with RNAs. E complex is dynamic and permits frequent redefinition of the 5' SS and BS. BBP influences U1 binding at the 5' SS by promoting long-lived complex formation. ECPs facilitate U1 association with RNAs with weak 5' SS and prevent U1 accumulation on RNAs containing hyperstabilized 5' SS. The data reveal a mechanism for how U1 binds the 5' SS and suggest that E complex harnesses this mechanism to stimulate recruitment and retention of U1 on introns.
Medical subject headings
- Protein Multimerization
- RNA Precursors
- RNA Splicing Factors
- RNA, Fungal
- Ribonucleoprotein, U1 Small Nuclear
- Saccharomyces cerevisiae
- Saccharomyces cerevisiae Proteins
- Spliceosomes