Two regions promote U11 small nuclear ribonucleoprotein particle binding to a retroviral splicing inhibitor element (negative regulator of splicing).
Abstract
The Rous sarcoma virus (RSV) negative regulator of splicing (NRS) is an RNA element that represses splicing and promotes polyadenylation of viral RNA. The NRS acts as a pseudo 5' splice site (ss), and serine-arginine (SR) proteins, U1snRNP, and U6 small nuclear ribonucleoproteins (snRNPs) are implicated in its function. The NRS also efficiently binds U11 snRNP of the U12-dependent splicing pathway, which is interesting, because U11 binds only poorly to authentic substrates that lack a U12-type 3' splice site. It is of considerable interest to understand how the low abundance U11 snRNP binds the NRS so well. Here we show that U11 can bind the NRS as a mono-snRNP in vitro and that a G-rich element located downstream of the U11 site is required for efficient binding. Mutational analyses indicated that two of four G tracts in this region were important for optimal U11 binding and that the G-rich region did not function indirectly by promoting U1 snRNP binding to an overlapping site. Surprisingly, inactivation of U2 snRNP also decreased U11 binding to the NRS. The NRS harbors a branch point-like/pyrimidine tract sequence (BP/Py) just upstream of the U1/U11 site that is characteristic of 3' splice sites. Deletion of this region decre...Continue Reading
References
A novel spliceosome containing U11, U12, and U5 snRNPs excises a minor class (AT-AC) intron in vitro
Citations
Related Concepts
Related Feeds
ASBMB Publications
The American Society for Biochemistry and Molecular Biology (ASBMB) includes the Journal of Biological Chemistry, Molecular & Cellular Proteomics, and the Journal of Lipid Research. Discover the latest research from ASBMB here.
Alternative splicing
Alternative splicing a regulated gene expression process that allows a single genetic sequence to code for multiple proteins. Here is that latest research.