Stem-loop 4 of U1 snRNA is essential for splicing and interacts with the U2 snRNP-specific SF3A1 protein during spliceosome assembly.

ABSTRACT: The pairing of 5' and 3' splice sites across an intron is a critical step in spliceosome formation and its regulation. Interactions that bring the two splice sites together during spliceosome assembly must occur with a high degree of specificity and fidelity to allow expression of functional mRNAs and make particular alternative splicing choices. Here, we report a new interaction between stem-loop 4 (SL4) of the U1 snRNA, which recognizes the 5' splice site, and a component of the U2 small nuclear ribonucleoprotein particle (snRNP) complex, which assembles across the intron at the 3' splice site. Using a U1 snRNP complementation assay, we found that SL4 is essential for splicing in vivo. The addition of free U1-SL4 to a splicing reaction in vitro inhibits splicing and blocks complex assemb

SUBMITTER: Sharma S 

PROVIDER: S-EPMC4233244 | biostudies-literature | 2014 Nov

REPOSITORIES: biostudies-literature