TY - JOUR
T1 - TRF2 Mediates Replication Initiation within Human Telomeres to Prevent Telomere Dysfunction
AU - Drosopoulos, William C.
AU - Deng, Zhong
AU - Twayana, Shyam
AU - Kosiyatrakul, Settapong T.
AU - Vladimirova, Olga
AU - Lieberman, Paul M.
AU - Schildkraut, Carl L.
N1 - Funding Information:
We thank Ken Chang (Cold Spring Harbor Laboratories Cancer Center Functional Genomics & Genetics core) for SNF2H- and Renilla luciferase-targeting shRNA sequences. We also thank Frederick Keeney (Wistar Imaging core facility) for image quantification and Samantha Soldan for assistance with GraphPad software. This work was supported by National Institutes of Health / National Institute of General Medical Sciences grant 5R01-GM045751 (to C.L.S.) and National Institutes of Health / National Cancer Institute grant 5R01-CA140652 (to P.M.L.). S.T. was supported by training grant T-32 NIH 5T32AG023475 .
Funding Information:
We thank Ken Chang (Cold Spring Harbor Laboratories Cancer Center Functional Genomics & Genetics core) for SNF2H- and Renilla luciferase-targeting shRNA sequences. We also thank Frederick Keeney (Wistar Imaging core facility) for image quantification and Samantha Soldan for assistance with GraphPad software. This work was supported by National Institutes of Health/National Institute of General Medical Sciences grant 5R01-GM045751 (to C.L.S.) and National Institutes of Health/National Cancer Institute grant 5R01-CA140652 (to P.M.L.). S.T. was supported by training grant T-32 NIH 5T32AG023475. W.C.D. conceived the study and designed the experiments. W.C.D. generated constructs and cell lines. W.C.D. S.T. and S.T.K. performed SMARD experiments. Z.D. performed ChIP and TLA experiments. Z.D. and O.V. performed metaphase experiments. W.C.D. analyzed the results and wrote the manuscript. W.C.D. Z.D. P.M.L. and C.L.S. edited the manuscript. The authors declare no competing interests.
Publisher Copyright:
© 2020 The Authors
PY - 2020/11/10
Y1 - 2020/11/10
N2 - The telomeric shelterin protein telomeric repeat-binding factor 2 (TRF2) recruits origin recognition complex (ORC) proteins, the foundational building blocks of DNA replication origins, to telomeres. We seek to determine whether TRF2-recruited ORC proteins give rise to functional origins in telomere repeat tracts. We find that reduction of telomeric recruitment of ORC2 by expression of an ORC interaction-defective TRF2 mutant significantly reduces telomeric initiation events in human cells. This reduction in initiation events is accompanied by telomere repeat loss, telomere aberrations and dysfunction. We demonstrate that telomeric origins are activated by induced replication stress to provide a key rescue mechanism for completing compromised telomere replication. Importantly, our studies also indicate that the chromatin remodeler SNF2H promotes telomeric initiation events by providing access for ORC2. Collectively, our findings reveal that active recruitment of ORC by TRF2 leads to formation of functional origins, providing an important mechanism for avoiding telomere dysfunction and rescuing challenged telomere replication.
AB - The telomeric shelterin protein telomeric repeat-binding factor 2 (TRF2) recruits origin recognition complex (ORC) proteins, the foundational building blocks of DNA replication origins, to telomeres. We seek to determine whether TRF2-recruited ORC proteins give rise to functional origins in telomere repeat tracts. We find that reduction of telomeric recruitment of ORC2 by expression of an ORC interaction-defective TRF2 mutant significantly reduces telomeric initiation events in human cells. This reduction in initiation events is accompanied by telomere repeat loss, telomere aberrations and dysfunction. We demonstrate that telomeric origins are activated by induced replication stress to provide a key rescue mechanism for completing compromised telomere replication. Importantly, our studies also indicate that the chromatin remodeler SNF2H promotes telomeric initiation events by providing access for ORC2. Collectively, our findings reveal that active recruitment of ORC by TRF2 leads to formation of functional origins, providing an important mechanism for avoiding telomere dysfunction and rescuing challenged telomere replication.
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U2 - 10.1016/j.celrep.2020.108379
DO - 10.1016/j.celrep.2020.108379
M3 - Article
C2 - 33176153
AN - SCOPUS:85095776787
SN - 2211-1247
VL - 33
JO - Cell Reports
JF - Cell Reports
IS - 6
M1 - 108379
ER -