The Mre11-Nbs1 Interface Is Essential for Viability and Tumor Suppression

Kim, Jun‐Hyun; Grosbart, Malgorzata; Anand, Roopesh; Wyman, Claire; Ćejka, Petr; Petrini, John H.J.

doi:10.1016/j.celrep.2016.12.035

Cited by 42 publications

(60 citation statements)

References 61 publications

(84 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This is in agreement with a recent study showing that an NBS1 fragment containing the MRE11 binding site but not the FHA-BRCT domains rescues the inviability of NBS1-deficient mouse embryonic fibroblasts (Kim et al, 2017). We show that both FHA and BRCT domains of NBS1 promote resection by MRE11 through interactions with phosphorylated CtIP.…”

Section: Introductionsupporting

confidence: 93%

“…When NBS1 senses that CtIP is phosphorylated, it promotes resection by a mechanism that is dependent on its interaction with MRE11. This is in agreement with a recent study showing that an NBS1 fragment containing the MRE11 binding site but not the FHA-BRCT domains rescues the inviability of NBS1-deficient mouse embryonic fibroblasts (Kim et al, 2017). Importantly, we identify an NBS1-independent DNA cleavage activity of MRE11-RAD50 and CtIP.…”

Section: Introductionsupporting

confidence: 93%

“…resection, despite this region mediated residual interaction with pCtIP ( Fig 2C). It has been demonstrated that the MRE11-RAD50 complex directly interacts with NBS1 via the MRE11 interaction region (MIR) within the C-terminal part of NBS1, with the most important motif located between residues 684-690 of NBS1 (Desai-Mehta et al, 2001;Schiller et al, 2012;Kim et al, 2017). This interaction facilitates MRN entry into the nucleus as only NBS1 contains the nuclear localization sequence.…”

Section: Nbs1 In Trans Promotes Endonucleolytic Cleavage By Mre11-radmentioning

confidence: 99%

See 2 more Smart Citations

NBS1 promotes the endonuclease activity of the MRE11‐RAD50 complex by sensing CtIP phosphorylation

et al. 2019

Self Cite

View full text Add to dashboard Cite

DNA end resection initiates DNA double‐strand break repair by homologous recombination. MRE11‐RAD50‐NBS1 and phosphorylated CtIP perform the first resection step via MRE11‐catalyzed endonucleolytic DNA cleavage. Human NBS1, more than its homologue Xrs2 in Saccharomyces cerevisiae, is crucial for this process, highlighting complex mechanisms that regulate the MRE11 nuclease in higher eukaryotes. Using a reconstituted system, we show here that NBS1, through its FHA and BRCT domains, functions as a sensor of CtIP phosphorylation. NBS1 then activates the MRE11‐RAD50 nuclease through direct physical interactions with MRE11. In the absence of NBS1, MRE11‐RAD50 exhibits a weaker nuclease activity, which requires CtIP but not strictly its phosphorylation. This identifies at least two mechanisms by which CtIP augments MRE11: a phosphorylation‐dependent mode through NBS1 and a phosphorylation‐independent mode without NBS1. In support, we show that limited DNA end resection occurs in vivo in the absence of the FHA and BRCT domains of NBS1. Collectively, our data suggest that NBS1 restricts the MRE11‐RAD50 nuclease to S‐G2 phase when CtIP is extensively phosphorylated. This defines mechanisms that regulate the MRE11 nuclease in DNA metabolism.

show abstract

Section: Introductionsupporting

confidence: 93%

Section: Introductionsupporting

confidence: 93%

Section: Nbs1 In Trans Promotes Endonucleolytic Cleavage By Mre11-radmentioning

confidence: 99%

See 1 more Smart Citation

NBS1 promotes the endonuclease activity of the MRE11‐RAD50 complex by sensing CtIP phosphorylation

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…These changes, which pull the linker to the Mre11 interface by ∼30 Å (19), are postulated to alter the Mre11 dimer symmetry thought to distinguish nuclease binding and activity for two-ended dsDNA breaks (symmetric dimer) and one-ended DNA forks (asymmetric dimer) (19). Overall, NBS1 (Xrs2 in S. cerevisiae ) acts a chaperone and adaptor coordinating interactions of the MR complex with other proteins (63, 64) and as a regulated activator of Mre11 nuclease (65). …”

Section: Mrn Complex: Structural Biochemistry and Biologymentioning

confidence: 99%

The MRE11–RAD50–NBS1 Complex Conducts the Orchestration of Damage Signaling and Outcomes to Stress in DNA Replication and Repair

Syed

Tainer

2018

Annu. Rev. Biochem.

324

345

View full text Add to dashboard Cite

Genomic instability in disease and its fidelity in health depend on the DNA damage response (DDR), regulated in part from the complex of meiotic recombination 11 homolog 1 (MRE11), ATP-binding cassette–ATPase (RAD50), and phosphopeptide-binding Nijmegen breakage syndrome protein 1 (NBS1). The MRE11–RAD50–NBS1 (MRN) complex forms a multifunctional DDR machine. Within its network assemblies, MRN is the core conductor for the initial and sustained responses to DNA double-strand breaks, stalled replication forks, dysfunctional telomeres, and viral DNA infection. MRN can interfere with cancer therapy and is an attractive target for precision medicine. Its conformations change the paradigm whereby kinases initiate damage sensing. Delineated results reveal kinase activation, posttranslational targeting, functional scaffolding, conformations storing binding energy and en-abling access, interactions with hub proteins such as replication protein A (RPA), and distinct networks at DNA breaks and forks. MRN biochemistry provides prototypic insights into how it initiates, implements, and regulates multifunctional responses to genomic stress.

show abstract

“…The dimerization loop is immediately adjacent to the Asn128–His129 (NH loop) loop region near the N-terminal Cap domain, suggesting that dimerization may reorganize the N-terminal domain at the active site based on the macromolecular organization of the full MRN complex in the presence of substrates. Nbs1 may act naturally to induce this macromolecular reorganization, and this change may also be promoted by its interactions with partners such as CtIP (Deshpande et al, 2016; Kim et al, 2017). Importantly, small molecule compounds may provide chemical master keys to lock this conformational change into a single position.…”

Section: Methods For Avatar Inhibitors Targeting Allosterymentioning

confidence: 99%

Targeting Allostery with Avatars to Design Inhibitors Assessed by Cell Activity: Dissecting MRE11 Endo- and Exonuclease Activities

Moiani

Ronato

Brosey

et al. 2018

Methods in Enzymology

View full text Add to dashboard Cite

For inhibitor design, as in most research, the best system is question dependent. We suggest structurally defined allostery to design specific inhibitors that target regions beyond active sites. We choose systems allowing efficient quality structures with conformational changes as optimal for structure-based design to optimize inhibitors. We maintain that evolutionarily related targets logically provide molecular avatars, where this Sanskrit term for descent includes ideas of functional relationships and of being a physical embodiment of the target’s essential features without requiring high sequence identity. Appropriate biochemical and cell assays provide quantitative measurements, and for biomedical impacts, any inhibitor’s activity should be validated in human cells. Specificity is effectively shown empirically by testing if mutations blocking target activity remove cellular inhibitor impact. We propose this approach to be superior to experiments testing for lack of cross-reactivity among possible related enzymes, which is a challenging negative experiment. As an exemplary avatar system for protein and DNA allosteric conformational controls, we focus here on developing separation-of-function inhibitors for meiotic recombination 11 nuclease activities. This was achieved not by targeting the active site but rather by geometrically impacting loop motifs analogously to ribosome antibiotics. These loops are neighboring the dimer interface and active site act in sculpting dsDNA and ssDNA into catalytically competent complexes. One of our design constraints is to preserve DNA substrate binding to geometrically block competing enzymes and pathways from the damaged site. We validate our allosteric approach to controlling outcomes in human cells by reversing the radiation sensitivity and genomic instability in BRCA mutant cells.

show abstract

The Mre11-Nbs1 Interface Is Essential for Viability and Tumor Suppression

Cited by 42 publications

References 61 publications

NBS1 promotes the endonuclease activity of the MRE11‐RAD50 complex by sensing CtIP phosphorylation

NBS1 promotes the endonuclease activity of the MRE11‐RAD50 complex by sensing CtIP phosphorylation

The MRE11–RAD50–NBS1 Complex Conducts the Orchestration of Damage Signaling and Outcomes to Stress in DNA Replication and Repair

Targeting Allostery with Avatars to Design Inhibitors Assessed by Cell Activity: Dissecting MRE11 Endo- and Exonuclease Activities

Contact Info

Product

Resources

About