Premium
Nuclear Export of Spliceosome‐discarded Intermediates
Author(s) -
Zeng Yi,
Staley Jonathan
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.lb226
Subject(s) - spliceosome , nuclear export signal , rna splicing , intron , cytoplasm , mature messenger rna , microbiology and biotechnology , chemistry , rna , cell nucleus , biochemistry , biology , gene
The precise removal of introns is essential for cell survival. To promote fidelity in nuclear pre‐mRNA splicing, the spliceosome rejects and discards suboptimal splicing substrates that have engaged the spliceosome. Although intron‐containing transcripts can be retained and degraded in the nucleus, various spliceosome‐discarded intermediates, such as mutated lariat intermediates, can be degraded in the cytoplasm. However, it is unknown why or how these suboptimal intermediates are exported for turnover. Here, we used RNA‐FISH to provide direct evidence that mutated lariat intermediates are exported into the cytoplasm and disruption of DEAH‐box ATPase Prp43p‐mediated discard of suboptimal intermediates blocks the export of mutated lariat intermediates. Further, we demonstrated that nucleoporins (Nup2p and Nup60p) and the general mRNA export receptor, Mex67p, play an essential role in the export of mutated lariat intermediates. Surprisingly, we found that Mlp1p, the nuclear retention factor, is important for the export of mutated lariat intermediates. Together, our findings establish the importance of the mRNA export pathway in transporting discarded intermediates for degradation.