TY - JOUR
T1 - Direct and indirect roles of RECQL4 in modulating base excision repair capacity
AU - Schurman, Shepherd H.
AU - Hedayati, Mohammad
AU - Wang, Zheng Ming
AU - Singh, Dharmendra K.
AU - Speina, Elzbieta
AU - Zhang, Yongqing
AU - Becker, Kevin
AU - Macris, Margaret
AU - Sung, Patrick
AU - Wilson, David M.
AU - Croteau, Deborah L.
AU - Bohr, Vilhelm A.
N1 - Funding Information:
This work was supported by the Intramural Research Program of the National Institute of Health, National Institute on Aging and by National Institute of Health Research Grant RO1ES-015632. Annual reports Z01 AG000726-16 and Z01 AG000727. E.S. was supported, in part, by a grant from the Polish Ministry of Science and Higher Education N303 391436.
PY - 2009
Y1 - 2009
N2 - RECQL4 is a human RecQ helicase which is mutated in approximately two-thirds of individuals with Rothmund-Thomson syndrome (RTS), a disease characterized at the cellular level by chromosomal instability. BLM and WRN are also human RecQ helicases, which are mutated in Bloom and Werner's syndrome, respectively, and associated with chromosomal instability as well as premature aging. Here we show that primary RTS and RECQL4 siRNA knockdown human fibroblasts accumulate more H2O2-induced DNA strand breaks than control cells, suggesting that RECQL4 may stimulate repair of H2O2 -induced DNA damage. RTS primary fibroblasts also accumulate more XRCC1 foci than control cells in response to endogenous or induced oxidative stress and have a high basal level of endogenous formamidopyrimidines. In cells treated with H2O2, RECQL4 co-localizes with APE1, and FEN1, key participants in base excision repair. Biochemical experiments indicate that RECQL4 specifically stimulates the apurinic endonuclease activity of APE1, the DNA strand displacement activity of DNA polymerase β, and incision of a 1- or 10-nucleotide flap DNA substrate by Flap Endonuclease I. Additionally, RTS cells display an upregulation of BER pathway genes and fail to respond like normal cells to oxidative stress. The data herein support a model in which RECQL4 regulates both directly and indirectly base excision repair capacity.
AB - RECQL4 is a human RecQ helicase which is mutated in approximately two-thirds of individuals with Rothmund-Thomson syndrome (RTS), a disease characterized at the cellular level by chromosomal instability. BLM and WRN are also human RecQ helicases, which are mutated in Bloom and Werner's syndrome, respectively, and associated with chromosomal instability as well as premature aging. Here we show that primary RTS and RECQL4 siRNA knockdown human fibroblasts accumulate more H2O2-induced DNA strand breaks than control cells, suggesting that RECQL4 may stimulate repair of H2O2 -induced DNA damage. RTS primary fibroblasts also accumulate more XRCC1 foci than control cells in response to endogenous or induced oxidative stress and have a high basal level of endogenous formamidopyrimidines. In cells treated with H2O2, RECQL4 co-localizes with APE1, and FEN1, key participants in base excision repair. Biochemical experiments indicate that RECQL4 specifically stimulates the apurinic endonuclease activity of APE1, the DNA strand displacement activity of DNA polymerase β, and incision of a 1- or 10-nucleotide flap DNA substrate by Flap Endonuclease I. Additionally, RTS cells display an upregulation of BER pathway genes and fail to respond like normal cells to oxidative stress. The data herein support a model in which RECQL4 regulates both directly and indirectly base excision repair capacity.
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U2 - 10.1093/hmg/ddp291
DO - 10.1093/hmg/ddp291
M3 - Article
C2 - 19567405
AN - SCOPUS:69449097526
SN - 0964-6906
VL - 18
SP - 3470
EP - 3483
JO - Human molecular genetics
JF - Human molecular genetics
IS - 18
ER -