TY - JOUR
T1 - RB localizes to DNA double-strand breaks and promotes DNA end resection and homologous recombination through the recruitment of BRG1
AU - Vélez-Cruz, Renier
AU - Manickavinayaham, Swarnalatha
AU - Biswas, Anup K.
AU - Clary, Regina Weaks
AU - Premkumar, Tolkappiyan
AU - Cole, Francesca
AU - Johnson, David G.
N1 - Funding Information:
This work was supported by the Cancer Prevention and Research Institute of Texas (R1213 to F.C., and RP140222 to D.G.J.), the National Institute of Health (grants CA079648 to D.G.J., and DP2HD087943 to F.C.), the Jeanne F. Shelby Scholarship Fund (F.C.), the R. Lee Clark Fellowship (F.C.), and a Cancer Core Support grant (CA016672). S.M. was supported by a fellowship from the Center for Cancer Epigenetics at University of Texas MD Anderson Cancer Center, and R.W.C. was supported by an American Legion Auxiliary Fellowship and a Cancer Answers/Sylvan Rodriguez Scholarship.
Publisher Copyright:
© 2016 Vélez-Cruz et al.
PY - 2016/11/15
Y1 - 2016/11/15
N2 - The retinoblastoma (RB) tumor suppressor is recognized as a master regulator that controls entry into the S phase of the cell cycle. Its loss leads to uncontrolled cell proliferation and is a hallmark of cancer. RB works by binding to members of the E2F family of transcription factors and recruiting chromatin modifiers to the promoters of E2F target genes. Here we show that RB also localizes to DNA double-strand breaks (DSBs) dependent on E2F1 and ATM kinase activity and promotes DSB repair through homologous recombination (HR), and its loss results in genome instability. RB is necessary for the recruitment of the BRG1 ATPase to DSBs, which stimulates DNA end resection and HR. A knock-in mutation of the ATM phosphorylation site on E2F1 (S29A) prevents the interaction between E2F1 and TopBP1 and recruitment of RB, E2F1, and BRG1 to DSBs. This knock-in mutation also impairs DNA repair, increases genomic instability, and renders mice hypersensitive to IR. Importantly, depletion of RB in osteosarcoma and breast cancer cell lines results in sensitivity to DNA-damaging drugs, which is further exacerbated by poly-ADP ribose polymerase (PARP) inhibitors. We uncovered a novel, nontranscriptional function for RB in HR, which could contribute to genome instability associated with RB loss.
AB - The retinoblastoma (RB) tumor suppressor is recognized as a master regulator that controls entry into the S phase of the cell cycle. Its loss leads to uncontrolled cell proliferation and is a hallmark of cancer. RB works by binding to members of the E2F family of transcription factors and recruiting chromatin modifiers to the promoters of E2F target genes. Here we show that RB also localizes to DNA double-strand breaks (DSBs) dependent on E2F1 and ATM kinase activity and promotes DSB repair through homologous recombination (HR), and its loss results in genome instability. RB is necessary for the recruitment of the BRG1 ATPase to DSBs, which stimulates DNA end resection and HR. A knock-in mutation of the ATM phosphorylation site on E2F1 (S29A) prevents the interaction between E2F1 and TopBP1 and recruitment of RB, E2F1, and BRG1 to DSBs. This knock-in mutation also impairs DNA repair, increases genomic instability, and renders mice hypersensitive to IR. Importantly, depletion of RB in osteosarcoma and breast cancer cell lines results in sensitivity to DNA-damaging drugs, which is further exacerbated by poly-ADP ribose polymerase (PARP) inhibitors. We uncovered a novel, nontranscriptional function for RB in HR, which could contribute to genome instability associated with RB loss.
KW - BRG1
KW - DNA end resection
KW - E2F1
KW - Homologous recombination
KW - Retinoblastoma
KW - SWI/SNF
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U2 - 10.1101/gad.288282.116
DO - 10.1101/gad.288282.116
M3 - Article
C2 - 27940962
AN - SCOPUS:85005949873
SN - 0890-9369
VL - 30
SP - 2500
EP - 2512
JO - Genes and Development
JF - Genes and Development
IS - 22
ER -