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Human HEL308 Localizes to Damaged Replication Forks and Unwinds Lagging Strand Structures

HEL308 is a superfamily II DNA helicase, conserved from archaea through to humans. HEL308 family members were originally isolated by their similarity to the Drosophila melanogaster Mus308 protein, which contributes to the repair of replication-blocking lesions such as DNA interstrand cross-links. Bi...

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Autores principales: Tafel, Agnieszka A., Wu, Leonard, McHugh, Peter J.
Formato: Texto
Lenguaje:English
Publicado: American Society for Biochemistry and Molecular Biology 2011
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3091193/
https://www.ncbi.nlm.nih.gov/pubmed/21398521
http://dx.doi.org/10.1074/jbc.M111.228189
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author Tafel, Agnieszka A.
Wu, Leonard
McHugh, Peter J.
author_facet Tafel, Agnieszka A.
Wu, Leonard
McHugh, Peter J.
author_sort Tafel, Agnieszka A.
collection PubMed
description HEL308 is a superfamily II DNA helicase, conserved from archaea through to humans. HEL308 family members were originally isolated by their similarity to the Drosophila melanogaster Mus308 protein, which contributes to the repair of replication-blocking lesions such as DNA interstrand cross-links. Biochemical studies have established that human HEL308 is an ATP-dependent enzyme that unwinds DNA with a 3′ to 5′ polarity, but little else is know about its mechanism. Here, we show that GFP-tagged HEL308 localizes to replication forks following camptothecin treatment. Moreover, HEL308 colocalizes with two factors involved in the repair of damaged forks by homologous recombination, Rad51 and FANCD2. Purified HEL308 requires a 3′ single-stranded DNA region to load and unwind duplex DNA structures. When incubated with substrates that model stalled replication forks, HEL308 preferentially unwinds the parental strands of a structure that models a fork with a nascent lagging strand, and the unwinding action of HEL308 is specifically stimulated by human replication protein A. Finally, we show that HEL308 appears to target and unwind from the junction between single-stranded to double-stranded DNA on model fork structures. Together, our results suggest that one role for HEL308 at sites of blocked replication might be to open up the parental strands to facilitate the loading of subsequent factors required for replication restart.
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spelling pubmed-30911932011-05-17 Human HEL308 Localizes to Damaged Replication Forks and Unwinds Lagging Strand Structures Tafel, Agnieszka A. Wu, Leonard McHugh, Peter J. J Biol Chem DNA and Chromosomes HEL308 is a superfamily II DNA helicase, conserved from archaea through to humans. HEL308 family members were originally isolated by their similarity to the Drosophila melanogaster Mus308 protein, which contributes to the repair of replication-blocking lesions such as DNA interstrand cross-links. Biochemical studies have established that human HEL308 is an ATP-dependent enzyme that unwinds DNA with a 3′ to 5′ polarity, but little else is know about its mechanism. Here, we show that GFP-tagged HEL308 localizes to replication forks following camptothecin treatment. Moreover, HEL308 colocalizes with two factors involved in the repair of damaged forks by homologous recombination, Rad51 and FANCD2. Purified HEL308 requires a 3′ single-stranded DNA region to load and unwind duplex DNA structures. When incubated with substrates that model stalled replication forks, HEL308 preferentially unwinds the parental strands of a structure that models a fork with a nascent lagging strand, and the unwinding action of HEL308 is specifically stimulated by human replication protein A. Finally, we show that HEL308 appears to target and unwind from the junction between single-stranded to double-stranded DNA on model fork structures. Together, our results suggest that one role for HEL308 at sites of blocked replication might be to open up the parental strands to facilitate the loading of subsequent factors required for replication restart. American Society for Biochemistry and Molecular Biology 2011-05-06 2011-03-11 /pmc/articles/PMC3091193/ /pubmed/21398521 http://dx.doi.org/10.1074/jbc.M111.228189 Text en © 2011 by The American Society for Biochemistry and Molecular Biology, Inc. Author's Choice—Final version full access. Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) applies to Author Choice Articles
spellingShingle DNA and Chromosomes
Tafel, Agnieszka A.
Wu, Leonard
McHugh, Peter J.
Human HEL308 Localizes to Damaged Replication Forks and Unwinds Lagging Strand Structures
title Human HEL308 Localizes to Damaged Replication Forks and Unwinds Lagging Strand Structures
title_full Human HEL308 Localizes to Damaged Replication Forks and Unwinds Lagging Strand Structures
title_fullStr Human HEL308 Localizes to Damaged Replication Forks and Unwinds Lagging Strand Structures
title_full_unstemmed Human HEL308 Localizes to Damaged Replication Forks and Unwinds Lagging Strand Structures
title_short Human HEL308 Localizes to Damaged Replication Forks and Unwinds Lagging Strand Structures
title_sort human hel308 localizes to damaged replication forks and unwinds lagging strand structures
topic DNA and Chromosomes
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3091193/
https://www.ncbi.nlm.nih.gov/pubmed/21398521
http://dx.doi.org/10.1074/jbc.M111.228189
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