Poster abstracts

Poster number 76 submitted by Imali Subasinghe

The spliceosomal protein Prp8 stabilizes a compact conformation of the U2-U6 complex

Subasinghe A. L. I. Subasinghe (Wayne state university), David Rueda (Wayne state university)

Abstract:
The spliceosome is a large, RNA-protein complex that catalyzes pre-mRNA splicing during mRNA maturation. The RNA components (small nuclear RNA; snRNAs) of the spliceosome have been well studied and are believed to be involved in the splicing catalysis. Although proteins are essential for splicing, they may not be directly involved in catalysis. Among hundreds of proteins, Prp8 is the only protein that interacts with all the catalytically important snRNAs. Therefore it is hypothesized that Prp8 may catalyze splicing either by directly participating in catalysis or by stabilizing the conformation of the catalytically active spliceosome. In order to test whether or not Prp8 stabilizes the active site conformation, we carried out single-molecule fluorescence resonance energy transfer (smFRET) experiments with catalytically important snRNAs U2 and U6 and Prp8. We observed that, in the presence of Prp8, the population of the high FRET conformation of U2-U6 that is thought to be the active conformation increased, indicating that one of the functions of Prp8 would be to stabilize the active site conformation of the spliceosome.

Keywords: Prp8, smFRET, spliceosome