NBS1 Phosphorylation Status Dictates Repair Choice of Dysfunctional Telomeres

Rekha Rai; Chunyi Hu; Cayla Broton; Yong Chen; Ming Lei; Sandy Chang

doi:10.1016/j.molcel.2017.01.016

NBS1 Phosphorylation Status Dictates Repair Choice of Dysfunctional Telomeres

Mol Cell. 2017 Mar 2;65(5):801-817.e4. doi: 10.1016/j.molcel.2017.01.016. Epub 2017 Feb 16.

Authors

Rekha Rai¹, Chunyi Hu², Cayla Broton¹, Yong Chen³, Ming Lei⁴, Sandy Chang⁵

Affiliations

¹ Department of Laboratory Medicine, Yale University School of Medicine, 330 Cedar Street, New Haven, CT 06520, USA.
² National Center for Protein Science Shanghai, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 333 Haike Road, Shanghai 201210, China, Yale University School of Medicine, 330 Cedar Street, New Haven, CT 06520, USA.
³ National Center for Protein Science Shanghai, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 333 Haike Road, Shanghai 201210, China, Yale University School of Medicine, 330 Cedar Street, New Haven, CT 06520, USA; Shanghai Research Center, Chinese Academy of Sciences, Shanghai 200031, China, Yale University School of Medicine, 330 Cedar Street, New Haven, CT 06520, USA.
⁴ National Center for Protein Science Shanghai, State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 333 Haike Road, Shanghai 201210, China, Yale University School of Medicine, 330 Cedar Street, New Haven, CT 06520, USA; Shanghai Research Center, Chinese Academy of Sciences, Shanghai 200031, China, Yale University School of Medicine, 330 Cedar Street, New Haven, CT 06520, USA. Electronic address: leim@sibcb.ac.cn.
⁵ Department of Laboratory Medicine, Yale University School of Medicine, 330 Cedar Street, New Haven, CT 06520, USA; Department of Pathology, Yale University School of Medicine, 330 Cedar Street, New Haven, CT 06520, USA; Molecular Biophysics and Biochemistry, Yale University School of Medicine, 330 Cedar Street, New Haven, CT 06520, USA. Electronic address: s.chang@yale.edu.

Abstract

Telomeres employ TRF2 to protect chromosome ends from activating the DNA damage sensor MRE11-RAD50-NBS1 (MRN), thereby repressing ATM-dependent DNA damage checkpoint responses. How TRF2 prevents MRN activation at dysfunctional telomeres is unclear. Here, we show that the phosphorylation status of NBS1 determines the repair pathway choice of dysfunctional telomeres. The crystal structure of the TRF2-NBS1 complex at 3.0 Å resolution shows that the NBS1 ₄₂₉YQLSP₄₃₃ motif interacts specifically with the TRF2^TRFH domain. Phosphorylation of NBS1 serine 432 by CDK2 in S/G2 dissociates NBS1 from TRF2, promoting TRF2-Apollo/SNM1B complex formation and the protection of leading-strand telomeres. Classical-NHEJ-mediated repair of telomeres lacking TRF2 requires phosphorylated NBS1^S432 to activate ATM, while interaction of de-phosphorylated NBS1^S432 with TRF2 promotes alternative-NHEJ repair of telomeres lacking POT1-TPP1. Our work advances understanding of how the TRF2^TRFH domain orchestrates telomere end protection and reveals how the phosphorylation status of the NBS1^S432 dictates repair pathway choice of dysfunctional telomeres.

MeSH terms

Aminopeptidases / genetics
Aminopeptidases / metabolism
Ataxia Telangiectasia Mutated Proteins / genetics
Ataxia Telangiectasia Mutated Proteins / metabolism
Binding Sites
Cell Cycle Proteins / chemistry
Cell Cycle Proteins / genetics
Cell Cycle Proteins / metabolism*
Cyclin-Dependent Kinase 2 / genetics
Cyclin-Dependent Kinase 2 / metabolism
DNA Breaks, Double-Stranded*
DNA End-Joining Repair*
DNA Repair Enzymes / genetics
DNA Repair Enzymes / metabolism
DNA-Binding Proteins
Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / genetics
Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / metabolism
Exodeoxyribonucleases
G1 Phase
G2 Phase
HCT116 Cells
Humans
Inhibitor of Apoptosis Proteins / genetics
Inhibitor of Apoptosis Proteins / metabolism
Models, Molecular
Nuclear Proteins / chemistry
Nuclear Proteins / genetics
Nuclear Proteins / metabolism*
Phosphorylation
Protein Binding
Protein Interaction Domains and Motifs
S Phase
Serine Proteases / genetics
Serine Proteases / metabolism
Shelterin Complex
Structure-Activity Relationship
Telomere / genetics
Telomere / metabolism*
Telomere / pathology
Telomere-Binding Proteins / genetics
Telomere-Binding Proteins / metabolism
Telomeric Repeat Binding Protein 2 / chemistry
Telomeric Repeat Binding Protein 2 / genetics
Telomeric Repeat Binding Protein 2 / metabolism*

Substances

ACD protein, human
Acd protein, mouse
BIRC6 protein, human
Cell Cycle Proteins
DNA-Binding Proteins
Inhibitor of Apoptosis Proteins
NBN protein, human
Nijmegen breakage syndrome 1 protein, mouse
Nuclear Proteins
POT1 protein, human
Shelterin Complex
TERF2 protein, human
TRF2 protein, mouse
Telomere-Binding Proteins
Telomeric Repeat Binding Protein 2
ATM protein, human
Ataxia Telangiectasia Mutated Proteins
CDK2 protein, human
Cyclin-Dependent Kinase 2
DCLRE1B protein, human
Exodeoxyribonucleases
Serine Proteases
Aminopeptidases
Dipeptidyl-Peptidases and Tripeptidyl-Peptidases
DNA Repair Enzymes

Abstract

MeSH terms

Substances

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