The human Werner syndrome protein stimulates repair of oxidative DNA base damage by the DNA glycosylase NEIL1.
The mammalian DNA glycosylase, NEIL1, specific for repair of oxidatively damaged bases in the genome via the base excision repair pathway, is activated by reactive oxygen species and prevents toxicity due to radiation. We show here that the Werner syndrome protein (WRN), a member of the RecQ family of DNA helicases, associates with NEIL1 in the early damage-sensing step of base excision repair. WRN stimulates NEIL1 in excision of oxidative lesions from bubble DNA substrates. The binary interaction between NEIL1 and WRN (K(D) = 60 nM) involves C-terminal residues 288-349 of NEIL1 and the RecQ C-terminal (RQC) region of WRN, and is independent of the helicase activity WRN. Exposure to oxidative stress enhances the NEIL-WRN association concomitant with their strong nuclear co-localization. WRN-depleted cells accumulate some prototypical oxidized bases (e.g. 8-oxoguanine, FapyG, and FapyA) indicating a physiological function of WRN in oxidative damage repair in mammalian genomes. Interestingly, WRN deficiency does not have an additive effect on in vivo damage accumulation in NEIL1 knockdown cells suggesting that WRN participates in the same repair pathway as NEIL1.
Das
Aditi
A
Department of Biochemistry and Molecular Biology and Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas 77555, USA.
Boldogh
Istvan
I
Lee
Jae Wan
JW
Harrigan
Jeanine A
JA
Hegde
Muralidhar L
ML
Piotrowski
Jason
J
de Souza Pinto
Nadja
N
Ramos
William
W
Greenberg
Marc M
MM
Hazra
Tapas K
TK
Mitra
Sankar
S
Bohr
Vilhelm A
VA
D045744:Cell Line, Tumor; D004249:DNA Damage / Q000502:physiology* / Q000528:radiation effects; D045647:DNA Glycosylases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004260:DNA Repair / Q000502:physiology* / Q000528:radiation effects; D005090:Exodeoxyribonucleases; D015894:Genome, Human / Q000502:physiology*; D006801:Humans; D010084:Oxidation-Reduction / Q000528:radiation effects; D018384:Oxidative Stress / Q000502:physiology* / Q000528:radiation effects; D011485:Protein Binding / Q000502:physiology / Q000528:radiation effects; D017434:Protein Structure, Tertiary / Q000502:physiology; D011743:Pyrimidines / Q000737:chemistry / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000737:chemistry / Q000378:metabolism; D053484:RecQ Helicases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D013379:Substrate Specificity / Q000502:physiology / Q000528:radiation effects; D000071657:Werner Syndrome Helicase
D011743:Pyrimidines; D017382:Reactive Oxygen Species; D005090:Exodeoxyribonucleases; D045647:DNA Glycosylases; C473634:NEIL1 protein, human; D053484:RecQ Helicases; C098785:WRN protein, human; D000071657:Werner Syndrome Helicase