Open AccessYeast Ntr1/Spp382 Mediates Prp43 Function in Postspliceosomes
Author(s) -
Kum-Loong Boon,
Tatsiana Auchynnikava,
Gretchen Edwalds-Gilbert,
J. David Barrass,
Alastair P. Droop,
Christophe Dez,
Jean D. Beggs
Publication year - 2006
Publication title -
molecular and cellular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.14
H-Index - 327
eISSN - 1067-8824
pISSN - 0270-7306
DOI - 10.1128/mcb.02347-05
Subject(s) - snrnp , rna splicing , spliceosome , intron , biology , splicing factor , microbiology and biotechnology , minor spliceosome , precursor mrna , saccharomyces cerevisiae , protein splicing , sr protein , rna binding protein , ribonucleoprotein , group ii intron , rna , genetics , yeast , gene
The Ntr1 and Ntr2 proteins ofSaccharomyces cerevisiae have been reported to interact with proteins involved in pre-mRNA splicing, but their roles in the splicing process are unknown. We show here that they associate with a postsplicing complex containing the excised intron and the spliceosomal U2, U5, and U6 snRNAs, supporting a link with a late stage in the pre-mRNA splicing process. Extract from cells that had been metabolically depleted of Ntr1 has low splicing activity and accumulates the excised intron. Also, the level of U4/U6 di-snRNP is increased but those of the free U5 and U6 snRNPs are decreased in Ntr1-depleted extract, and increased levels of U2 and decreased levels of U4 are found associated with the U5 snRNP protein Prp8. These results suggest a requirement for Ntr1 for turnover of the excised intron complex and recycling of snRNPs. Ntr1 interacts directly or indirectly with the intron release factor Prp43 and is required for its association with the excised intron. We propose that Ntr1 promotes release of excised introns from splicing complexes by acting as a spliceosome receptor or RNA-targeting factor for Prp43, possibly assisted by the Ntr2 protein.