The involvement of human RECQL4 in DNA double-strand break repair

TY - JOUR

T1 - The involvement of human RECQL4 in DNA double-strand break repair

AU - Singh, Dharmendra Kumar

AU - Karmakar, Parimal

AU - Aamann, Maria Diget

AU - Schurman, Shepherd H

AU - May, Alfred

AU - Croteau, Deborah L

AU - Burks, Lynnette

AU - Plon, Sharon E

AU - Bohr, Vilhelm A

PY - 2010/6/1

Y1 - 2010/6/1

N2 - Rothmund-Thomson syndrome (RTS) is an autosomal recessive hereditary disorder associated with mutation in RECQL4 gene, a member of the human RecQ helicases. The disease is characterized by genomic instability, skeletal abnormalities and predisposition to malignant tumors, especially osteosarcomas. The precise role of RECQL4 in cellular pathways is largely unknown; however, recent evidence suggests its involvement in multiple DNA metabolic pathways. This study investigates the roles of RECQL4 in DNA double-strand break (DSB) repair. The results show that RECQL4-deficient fibroblasts are moderately sensitive to γ-irradiation and accumulate more γH2AX and 53BP1 foci than control fibroblasts. This is suggestive of defects in efficient repair of DSB's in the RECQL4-deficient fibroblasts. Real time imaging of live cells using laser confocal microscopy shows that RECQL4 is recruited early to laser-induced DSBs and remains for a shorter duration than WRN and BLM, indicating its distinct role in repair of DSBs. Endogenous RECQL4 also colocalizes with γH2AX at the site of DSBs. The RECQL4 domain responsible for its DNA damage localization has been mapped to the unique N-terminus domain between amino acids 363-492, which shares no homology to recruitment domains of WRN and BLM to the DSBs. Further, the recruitment of RECQL4 to laser-induced DNA damage is independent of functional WRN, BLM or ATM proteins. These results suggest distinct cellular dynamics for RECQL4 protein at the site of laserinduced DSB and that it might play important roles in efficient repair of DSB's.

AB - Rothmund-Thomson syndrome (RTS) is an autosomal recessive hereditary disorder associated with mutation in RECQL4 gene, a member of the human RecQ helicases. The disease is characterized by genomic instability, skeletal abnormalities and predisposition to malignant tumors, especially osteosarcomas. The precise role of RECQL4 in cellular pathways is largely unknown; however, recent evidence suggests its involvement in multiple DNA metabolic pathways. This study investigates the roles of RECQL4 in DNA double-strand break (DSB) repair. The results show that RECQL4-deficient fibroblasts are moderately sensitive to γ-irradiation and accumulate more γH2AX and 53BP1 foci than control fibroblasts. This is suggestive of defects in efficient repair of DSB's in the RECQL4-deficient fibroblasts. Real time imaging of live cells using laser confocal microscopy shows that RECQL4 is recruited early to laser-induced DSBs and remains for a shorter duration than WRN and BLM, indicating its distinct role in repair of DSBs. Endogenous RECQL4 also colocalizes with γH2AX at the site of DSBs. The RECQL4 domain responsible for its DNA damage localization has been mapped to the unique N-terminus domain between amino acids 363-492, which shares no homology to recruitment domains of WRN and BLM to the DSBs. Further, the recruitment of RECQL4 to laser-induced DNA damage is independent of functional WRN, BLM or ATM proteins. These results suggest distinct cellular dynamics for RECQL4 protein at the site of laserinduced DSB and that it might play important roles in efficient repair of DSB's.

KW - Cell Line

KW - Cell Survival

KW - DNA

KW - DNA Breaks, Double-Stranded

KW - DNA Repair

KW - Histones

KW - Humans

KW - RecQ Helicases

KW - Rothmund-Thomson Syndrome

U2 - 10.1111/j.1474-9726.2010.00562.x

DO - 10.1111/j.1474-9726.2010.00562.x

M3 - Journal article

C2 - 20222902

SN - 1474-9718

VL - 9

SP - 358

EP - 371

JO - Aging Cell

JF - Aging Cell

IS - 3

ER -