Cargando…

Spliceosome assembly in the absence of stable U4/U6 RNA pairing

The cycle of spliceosome assembly, intron excision, and spliceosome disassembly involves large-scale structural rearrangements of U6 snRNA that are functionally important. U6 enters the splicing pathway bound to the Prp24 protein, which chaperones annealing of U6 to U4 RNA to form a U4/U6 di-snRNP....

Descripción completa

Detalles Bibliográficos
Autores principales: Burke, Jordan E., Butcher, Samuel E., Brow, David A.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Cold Spring Harbor Laboratory Press 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4408799/
https://www.ncbi.nlm.nih.gov/pubmed/25762536
http://dx.doi.org/10.1261/rna.048421.114
_version_ 1782368109124911104
author Burke, Jordan E.
Butcher, Samuel E.
Brow, David A.
author_facet Burke, Jordan E.
Butcher, Samuel E.
Brow, David A.
author_sort Burke, Jordan E.
collection PubMed
description The cycle of spliceosome assembly, intron excision, and spliceosome disassembly involves large-scale structural rearrangements of U6 snRNA that are functionally important. U6 enters the splicing pathway bound to the Prp24 protein, which chaperones annealing of U6 to U4 RNA to form a U4/U6 di-snRNP. During catalytic activation of the assembled spliceosome, U4 snRNP is released and U6 is paired to U2 snRNA. Here we show that point mutations in U4 and U6 that decrease U4/U6 base-pairing in vivo are lethal in combination. However, this synthetic phenotype is rescued by a mutation in U6 that alters a U6–Prp24 contact and stabilizes U2/U6. Remarkably, the resulting viable triple mutant strain lacks detectable U4/U6 base-pairing and U4/U6 di-snRNP. Instead, this strain accumulates free U4 snRNP, protein-free U6 RNA, and a novel complex containing U2/U6 di-snRNP. Further mutational analysis indicates that disruption of the U6–Prp24 interaction rather than stabilization of U2/U6 renders stable U4/U6 di-snRNP assembly nonessential. We propose that an essential function of U4/U6 pairing is to displace Prp24 from U6 RNA, and thus a destabilized U6–Prp24 complex renders stable U4/U6 pairing nonessential.
format Online
Article
Text
id pubmed-4408799
institution National Center for Biotechnology Information
language English
publishDate 2015
publisher Cold Spring Harbor Laboratory Press
record_format MEDLINE/PubMed
spelling pubmed-44087992016-05-01 Spliceosome assembly in the absence of stable U4/U6 RNA pairing Burke, Jordan E. Butcher, Samuel E. Brow, David A. RNA Articles The cycle of spliceosome assembly, intron excision, and spliceosome disassembly involves large-scale structural rearrangements of U6 snRNA that are functionally important. U6 enters the splicing pathway bound to the Prp24 protein, which chaperones annealing of U6 to U4 RNA to form a U4/U6 di-snRNP. During catalytic activation of the assembled spliceosome, U4 snRNP is released and U6 is paired to U2 snRNA. Here we show that point mutations in U4 and U6 that decrease U4/U6 base-pairing in vivo are lethal in combination. However, this synthetic phenotype is rescued by a mutation in U6 that alters a U6–Prp24 contact and stabilizes U2/U6. Remarkably, the resulting viable triple mutant strain lacks detectable U4/U6 base-pairing and U4/U6 di-snRNP. Instead, this strain accumulates free U4 snRNP, protein-free U6 RNA, and a novel complex containing U2/U6 di-snRNP. Further mutational analysis indicates that disruption of the U6–Prp24 interaction rather than stabilization of U2/U6 renders stable U4/U6 di-snRNP assembly nonessential. We propose that an essential function of U4/U6 pairing is to displace Prp24 from U6 RNA, and thus a destabilized U6–Prp24 complex renders stable U4/U6 pairing nonessential. Cold Spring Harbor Laboratory Press 2015-05 /pmc/articles/PMC4408799/ /pubmed/25762536 http://dx.doi.org/10.1261/rna.048421.114 Text en © 2015 Burke et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society http://creativecommons.org/licenses/by-nc/4.0/ This article is distributed exclusively by the RNA Society for the first 12 months after the full-issue publication date (see http://rnajournal.cshlp.org/site/misc/terms.xhtml). After 12 months, it is available under a Creative Commons License (Attribution-NonCommercial 4.0 International), as described at http://creativecommons.org/licenses/by-nc/4.0/.
spellingShingle Articles
Burke, Jordan E.
Butcher, Samuel E.
Brow, David A.
Spliceosome assembly in the absence of stable U4/U6 RNA pairing
title Spliceosome assembly in the absence of stable U4/U6 RNA pairing
title_full Spliceosome assembly in the absence of stable U4/U6 RNA pairing
title_fullStr Spliceosome assembly in the absence of stable U4/U6 RNA pairing
title_full_unstemmed Spliceosome assembly in the absence of stable U4/U6 RNA pairing
title_short Spliceosome assembly in the absence of stable U4/U6 RNA pairing
title_sort spliceosome assembly in the absence of stable u4/u6 rna pairing
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4408799/
https://www.ncbi.nlm.nih.gov/pubmed/25762536
http://dx.doi.org/10.1261/rna.048421.114
work_keys_str_mv AT burkejordane spliceosomeassemblyintheabsenceofstableu4u6rnapairing
AT butchersamuele spliceosomeassemblyintheabsenceofstableu4u6rnapairing
AT browdavida spliceosomeassemblyintheabsenceofstableu4u6rnapairing