Bi-directional routing of DNA mismatch repair protein human exonuclease 1 to replication foci and DNA double strand breaks

TY - JOUR

T1 - Bi-directional routing of DNA mismatch repair protein human exonuclease 1 to replication foci and DNA double strand breaks

AU - Liberti, Sascha E

AU - Andersen, Sofie Dabros

AU - Wang, Jing

AU - May, Alfred

AU - Miron, Simona

AU - Perderiset, Mylene

AU - Keijzers, Guido

AU - Nielsen, Finn C

AU - Charbonnier, Jean-Baptiste

AU - Bohr, Vilhelm A

AU - Rasmussen, Lene J

N1 - Copyright © 2010 Elsevier B.V. All rights reserved.

PY - 2011/1/2

Y1 - 2011/1/2

N2 - Human exonuclease 1 (hEXO1) is implicated in DNA metabolism, including replication, recombination and repair, substantiated by its interactions with PCNA, DNA helicases BLM and WRN, and several DNA mismatch repair (MMR) proteins. We investigated the sub-nuclear localization of hEXO1 during S-phase progression and in response to laser-induced DNA double strand breaks (DSBs). We show that hEXO1 and PCNA co-localize in replication foci. This apparent interaction is sustained throughout S-phase. We also demonstrate that hEXO1 is rapidly recruited to DNA DSBs. We have identified a PCNA interacting protein (PIP-box) region on hEXO1 located in its COOH-terminal ((788)QIKLNELW(795)). This motif is essential for PCNA binding and co-localization during S-phase. Recruitment of hEXO1 to DNA DSB sites is dependent on the MMR protein hMLH1. We show that two distinct hMLH1 interaction regions of hEXO1 (residues 390-490 and 787-846) are required to direct the protein to the DNA damage site. Our results reveal that protein domains in hEXO1 in conjunction with specific protein interactions control bi-directional routing of hEXO1 between on-going DNA replication and repair processes in living cells.

AB - Human exonuclease 1 (hEXO1) is implicated in DNA metabolism, including replication, recombination and repair, substantiated by its interactions with PCNA, DNA helicases BLM and WRN, and several DNA mismatch repair (MMR) proteins. We investigated the sub-nuclear localization of hEXO1 during S-phase progression and in response to laser-induced DNA double strand breaks (DSBs). We show that hEXO1 and PCNA co-localize in replication foci. This apparent interaction is sustained throughout S-phase. We also demonstrate that hEXO1 is rapidly recruited to DNA DSBs. We have identified a PCNA interacting protein (PIP-box) region on hEXO1 located in its COOH-terminal ((788)QIKLNELW(795)). This motif is essential for PCNA binding and co-localization during S-phase. Recruitment of hEXO1 to DNA DSB sites is dependent on the MMR protein hMLH1. We show that two distinct hMLH1 interaction regions of hEXO1 (residues 390-490 and 787-846) are required to direct the protein to the DNA damage site. Our results reveal that protein domains in hEXO1 in conjunction with specific protein interactions control bi-directional routing of hEXO1 between on-going DNA replication and repair processes in living cells.

U2 - 10.1016/j.dnarep.2010.09.023

DO - 10.1016/j.dnarep.2010.09.023

M3 - Journal article

C2 - 20970388

SN - 1568-7864

VL - 10

SP - 73

EP - 86

JO - DNA Repair

JF - DNA Repair

IS - 1

ER -