The MRX complex regulates Exo1 resection activity by altering DNA end structure

Elisa Gobbini; Corinne Cassani; Jacopo Vertemara; Weibin Wang; Fabiana Mambretti; Erika Casari; Patrick Sung; Renata Tisi; Giuseppe Zampella; Maria Pia Longhese

doi:10.15252/embj.201798588

The MRX complex regulates Exo1 resection activity by altering DNA end structure

Elisa Gobbini, Corinne Cassani, Jacopo Vertemara, Weibin Wang, Fabiana Mambretti, Erika Casari, Patrick Sung, Renata Tisi, Giuseppe Zampella, Maria Pia Longhese

Research output: Contribution to journal › Article › peer-review

16 Scopus citations

Abstract

Homologous recombination is triggered by nucleolytic degradation (resection) of DNA double-strand breaks (DSBs). DSB resection requires the Mre11-Rad50-Xrs2 (MRX) complex, which promotes the activity of Exo1 nuclease through a poorly understood mechanism. Here, we describe the Mre11-R10T mutant variant that accelerates DSB resection compared to wild-type Mre11 by potentiating Exo1-mediated processing. This increased Exo1 resection activity leads to a decreased association of the Ku complex to DSBs and an enhanced DSB resection in G1, indicating that Exo1 has a direct function in preventing Ku association with DSBs. Molecular dynamics simulations show that rotation of the Mre11 capping domains is able to induce unwinding of double-strand DNA (dsDNA). The R10T substitution causes altered orientation of the Mre11 capping domain that leads to persistent melting of the dsDNA end. We propose that MRX creates a specific DNA end structure that promotes Exo1 resection activity by facilitating the persistence of this nuclease on the DSB ends, uncovering a novel MRX function in DSB resection.

Original language	English (US)
Article number	e98588
Journal	EMBO Journal
Volume	37
Issue number	16
DOIs	https://doi.org/10.15252/embj.201798588
State	Published - Aug 15 2018
Externally published	Yes

Keywords

Exo1
MRX
Sae2
double-strand break
resection

ASJC Scopus subject areas

Neuroscience(all)
Molecular Biology
Biochemistry, Genetics and Molecular Biology(all)
Immunology and Microbiology(all)

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10.15252/embj.201798588

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title = "The MRX complex regulates Exo1 resection activity by altering DNA end structure",

abstract = "Homologous recombination is triggered by nucleolytic degradation (resection) of DNA double-strand breaks (DSBs). DSB resection requires the Mre11-Rad50-Xrs2 (MRX) complex, which promotes the activity of Exo1 nuclease through a poorly understood mechanism. Here, we describe the Mre11-R10T mutant variant that accelerates DSB resection compared to wild-type Mre11 by potentiating Exo1-mediated processing. This increased Exo1 resection activity leads to a decreased association of the Ku complex to DSBs and an enhanced DSB resection in G1, indicating that Exo1 has a direct function in preventing Ku association with DSBs. Molecular dynamics simulations show that rotation of the Mre11 capping domains is able to induce unwinding of double-strand DNA (dsDNA). The R10T substitution causes altered orientation of the Mre11 capping domain that leads to persistent melting of the dsDNA end. We propose that MRX creates a specific DNA end structure that promotes Exo1 resection activity by facilitating the persistence of this nuclease on the DSB ends, uncovering a novel MRX function in DSB resection.",

keywords = "Exo1, MRX, Sae2, double-strand break, resection",

author = "Elisa Gobbini and Corinne Cassani and Jacopo Vertemara and Weibin Wang and Fabiana Mambretti and Erika Casari and Patrick Sung and Renata Tisi and Giuseppe Zampella and Longhese, {Maria Pia}",

note = "Funding Information: We thank M. Clerici for preliminary experiments and discussion and G. Lucchini for critical reading of the manuscript. We also thank J. Haber, N. Kleckner, R. Kolodner and M. Resnick for yeast strains. This work was supported by the Associazione Italiana per la Ricerca sul Cancro (AIRC) (IG grant 19783) and Progetti di Ricerca di Interesse Nazionale (PRIN) 2015 to M.P.L and by grant RO1 ES015632 from the US National Institutes of Health to P.S. C.C. was supported by a fellowship from Fondazione Italiana Ricerca sul Cancro (FIRC). Publisher Copyright: {\textcopyright} 2018 The Authors",

year = "2018",

month = aug,

day = "15",

doi = "10.15252/embj.201798588",

language = "English (US)",

volume = "37",

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T1 - The MRX complex regulates Exo1 resection activity by altering DNA end structure

AU - Gobbini, Elisa

AU - Cassani, Corinne

AU - Vertemara, Jacopo

AU - Wang, Weibin

AU - Mambretti, Fabiana

AU - Casari, Erika

AU - Sung, Patrick

AU - Tisi, Renata

AU - Zampella, Giuseppe

AU - Longhese, Maria Pia

N1 - Funding Information: We thank M. Clerici for preliminary experiments and discussion and G. Lucchini for critical reading of the manuscript. We also thank J. Haber, N. Kleckner, R. Kolodner and M. Resnick for yeast strains. This work was supported by the Associazione Italiana per la Ricerca sul Cancro (AIRC) (IG grant 19783) and Progetti di Ricerca di Interesse Nazionale (PRIN) 2015 to M.P.L and by grant RO1 ES015632 from the US National Institutes of Health to P.S. C.C. was supported by a fellowship from Fondazione Italiana Ricerca sul Cancro (FIRC). Publisher Copyright: © 2018 The Authors

PY - 2018/8/15

Y1 - 2018/8/15

N2 - Homologous recombination is triggered by nucleolytic degradation (resection) of DNA double-strand breaks (DSBs). DSB resection requires the Mre11-Rad50-Xrs2 (MRX) complex, which promotes the activity of Exo1 nuclease through a poorly understood mechanism. Here, we describe the Mre11-R10T mutant variant that accelerates DSB resection compared to wild-type Mre11 by potentiating Exo1-mediated processing. This increased Exo1 resection activity leads to a decreased association of the Ku complex to DSBs and an enhanced DSB resection in G1, indicating that Exo1 has a direct function in preventing Ku association with DSBs. Molecular dynamics simulations show that rotation of the Mre11 capping domains is able to induce unwinding of double-strand DNA (dsDNA). The R10T substitution causes altered orientation of the Mre11 capping domain that leads to persistent melting of the dsDNA end. We propose that MRX creates a specific DNA end structure that promotes Exo1 resection activity by facilitating the persistence of this nuclease on the DSB ends, uncovering a novel MRX function in DSB resection.

AB - Homologous recombination is triggered by nucleolytic degradation (resection) of DNA double-strand breaks (DSBs). DSB resection requires the Mre11-Rad50-Xrs2 (MRX) complex, which promotes the activity of Exo1 nuclease through a poorly understood mechanism. Here, we describe the Mre11-R10T mutant variant that accelerates DSB resection compared to wild-type Mre11 by potentiating Exo1-mediated processing. This increased Exo1 resection activity leads to a decreased association of the Ku complex to DSBs and an enhanced DSB resection in G1, indicating that Exo1 has a direct function in preventing Ku association with DSBs. Molecular dynamics simulations show that rotation of the Mre11 capping domains is able to induce unwinding of double-strand DNA (dsDNA). The R10T substitution causes altered orientation of the Mre11 capping domain that leads to persistent melting of the dsDNA end. We propose that MRX creates a specific DNA end structure that promotes Exo1 resection activity by facilitating the persistence of this nuclease on the DSB ends, uncovering a novel MRX function in DSB resection.

KW - Exo1

KW - MRX

KW - Sae2

KW - double-strand break

KW - resection

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U2 - 10.15252/embj.201798588

DO - 10.15252/embj.201798588

M3 - Article

C2 - 29925516

AN - SCOPUS:85051421234

SN - 0261-4189

VL - 37

JO - EMBO Journal

JF - EMBO Journal

IS - 16

M1 - e98588

ER -

The MRX complex regulates Exo1 resection activity by altering DNA end structure

Abstract

Keywords

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