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Studies with recombinant U7 snRNP demonstrate that CPSF73 is both an endonuclease and a 5′–3′ exonuclease
Metazoan replication-dependent histone pre-mRNAs are cleaved at the 3′ end by U7 snRNP, an RNA-guided endonuclease that contains U7 snRNA, seven proteins of the Sm ring, FLASH, and four polyadenylation factors: symplekin, CPSF73, CPSF100, and CstF64. A fully recombinant U7 snRNP was recently reconst...
Autores principales: | , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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Cold Spring Harbor Laboratory Press
2020
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7491329/ https://www.ncbi.nlm.nih.gov/pubmed/32554553 http://dx.doi.org/10.1261/rna.076273.120 |
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author | Yang, Xiao-cui Sun, Yadong Aik, Wei Shen Marzluff, William F. Tong, Liang Dominski, Zbigniew |
author_facet | Yang, Xiao-cui Sun, Yadong Aik, Wei Shen Marzluff, William F. Tong, Liang Dominski, Zbigniew |
author_sort | Yang, Xiao-cui |
collection | PubMed |
description | Metazoan replication-dependent histone pre-mRNAs are cleaved at the 3′ end by U7 snRNP, an RNA-guided endonuclease that contains U7 snRNA, seven proteins of the Sm ring, FLASH, and four polyadenylation factors: symplekin, CPSF73, CPSF100, and CstF64. A fully recombinant U7 snRNP was recently reconstituted from all 13 components for functional and structural studies and shown to accurately cleave histone pre-mRNAs. Here, we analyzed the activity of recombinant U7 snRNP in more detail. We demonstrate that in addition to cleaving histone pre-mRNAs endonucleolytically, reconstituted U7 snRNP acts as a 5′–3′ exonuclease that degrades the downstream product generated from histone pre-mRNAs as a result of the endonucleolytic cleavage. Surprisingly, recombinant U7 snRNP also acts as an endonuclease on single-stranded DNA substrates. All these activities depend on the ability of U7 snRNA to base-pair with the substrate and on the presence of the amino-terminal domain (NTD) of symplekin in either cis or trans, and are abolished by mutations within the catalytic center of CPSF73, or by binding of the NTD to the SSU72 phosphatase of RNA polymerase II. Altogether, our results demonstrate that recombinant U7 snRNP functionally mimics its endogenous counterpart and provide evidence that CPSF73 is both an endonuclease and a 5′–3′ exonuclease, consistent with the activity of other members of the β-CASP family. Our results also raise the intriguing possibility that CPSF73 may be involved in some aspects of DNA metabolism in vivo. |
format | Online Article Text |
id | pubmed-7491329 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | Cold Spring Harbor Laboratory Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-74913292021-10-01 Studies with recombinant U7 snRNP demonstrate that CPSF73 is both an endonuclease and a 5′–3′ exonuclease Yang, Xiao-cui Sun, Yadong Aik, Wei Shen Marzluff, William F. Tong, Liang Dominski, Zbigniew RNA Article Metazoan replication-dependent histone pre-mRNAs are cleaved at the 3′ end by U7 snRNP, an RNA-guided endonuclease that contains U7 snRNA, seven proteins of the Sm ring, FLASH, and four polyadenylation factors: symplekin, CPSF73, CPSF100, and CstF64. A fully recombinant U7 snRNP was recently reconstituted from all 13 components for functional and structural studies and shown to accurately cleave histone pre-mRNAs. Here, we analyzed the activity of recombinant U7 snRNP in more detail. We demonstrate that in addition to cleaving histone pre-mRNAs endonucleolytically, reconstituted U7 snRNP acts as a 5′–3′ exonuclease that degrades the downstream product generated from histone pre-mRNAs as a result of the endonucleolytic cleavage. Surprisingly, recombinant U7 snRNP also acts as an endonuclease on single-stranded DNA substrates. All these activities depend on the ability of U7 snRNA to base-pair with the substrate and on the presence of the amino-terminal domain (NTD) of symplekin in either cis or trans, and are abolished by mutations within the catalytic center of CPSF73, or by binding of the NTD to the SSU72 phosphatase of RNA polymerase II. Altogether, our results demonstrate that recombinant U7 snRNP functionally mimics its endogenous counterpart and provide evidence that CPSF73 is both an endonuclease and a 5′–3′ exonuclease, consistent with the activity of other members of the β-CASP family. Our results also raise the intriguing possibility that CPSF73 may be involved in some aspects of DNA metabolism in vivo. Cold Spring Harbor Laboratory Press 2020-10 /pmc/articles/PMC7491329/ /pubmed/32554553 http://dx.doi.org/10.1261/rna.076273.120 Text en © 2020 Yang 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 | Article Yang, Xiao-cui Sun, Yadong Aik, Wei Shen Marzluff, William F. Tong, Liang Dominski, Zbigniew Studies with recombinant U7 snRNP demonstrate that CPSF73 is both an endonuclease and a 5′–3′ exonuclease |
title | Studies with recombinant U7 snRNP demonstrate that CPSF73 is both an endonuclease and a 5′–3′ exonuclease |
title_full | Studies with recombinant U7 snRNP demonstrate that CPSF73 is both an endonuclease and a 5′–3′ exonuclease |
title_fullStr | Studies with recombinant U7 snRNP demonstrate that CPSF73 is both an endonuclease and a 5′–3′ exonuclease |
title_full_unstemmed | Studies with recombinant U7 snRNP demonstrate that CPSF73 is both an endonuclease and a 5′–3′ exonuclease |
title_short | Studies with recombinant U7 snRNP demonstrate that CPSF73 is both an endonuclease and a 5′–3′ exonuclease |
title_sort | studies with recombinant u7 snrnp demonstrate that cpsf73 is both an endonuclease and a 5′–3′ exonuclease |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7491329/ https://www.ncbi.nlm.nih.gov/pubmed/32554553 http://dx.doi.org/10.1261/rna.076273.120 |
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