Sensing DNA Damage Through ATRIP Recognition of RPA-ssDNA Complexes

@article{Zou2003SensingDD,
  title={Sensing DNA Damage Through ATRIP Recognition of RPA-ssDNA Complexes},
  author={Lee Zou and Stephen J. Elledge},
  journal={Science},
  year={2003},
  volume={300},
  pages={1542 - 1548}
}
The function of the ATR (ataxia-telangiectasia mutated– and Rad3-related)–ATRIP (ATR-interacting protein) protein kinase complex is crucial for the cellular response to replication stress and DNA damage. Here, we show that replication protein A (RPA), a protein complex that associates with single-stranded DNA (ssDNA), is required for the recruitment of ATR to sites of DNA damage and for ATR-mediated Chk1 activation in human cells. In vitro, RPA stimulates the binding of ATRIP to ssDNA. The… 

A Novel Protein Activity Mediates DNA Binding of an ATR-ATRIP Complex*

It is found that both ATR and ATRIP associate with chromatin in vivo, and they exist as a large molecular weight complex that can bind single-stranded (ss)DNA cellulose in vitro and a distinct ATR-ATRIP complex is able to bind to DNA with lower affinity in the absence of RPA.

Reconstitution of RPA-covered single-stranded DNA-activated ATR-Chk1 signaling

An in vitro checkpoint system in which RPA-ssDNA and TopBP1 are essential for phosphorylation of Chk1 by the purified ATR-ATRIP complex, and an alternative form of RPA (aRPA), which does not support DNA replication, can substitute for the checkpoint function of R PA in vitro, thus revealing a potential role for aRPA in the activation of ATR kinase.

ATRIP associates with replication protein A-coated ssDNA through multiple interactions.

  • Y. NamikiL. Zou
  • Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 2006
It is shown that ATRIP associates with RPA-ssDNA through multiple interactions, and one internal region of ATRIP exhibited affinity to ssDNA, suggesting that AT RIP may interact with ssDNA in the ATRIP-RPA-SSDNA complex.

Ddc2ATRIP promotes Mec1ATR activation at RPA-ssDNA tracts

It is shown that Ddc2 promotes Mec1 activation independently of Ddc1/Dpb11/Dna2 function in vivo and through ssDNA recognition in vitro, which supports a model in which Ddc 2 promotes MEC1 activation at RPA-ssDNA tracts.

RPA70 depletion induces hSSB1/2-INTS3 complex to initiate ATR signaling

It is reported that the single-stranded DNA-binding protein complex, hSSB1/2-INTS3 can recruit the checkpoint complex to initiate ATR signaling.

Function of a Conserved Checkpoint Recruitment Domain in ATRIP Proteins

The results support the idea of a multistep model for ATR activation that requires separable localization and activation functions of ATRIP, and demonstrate that the CRD is critical for localization and optimal DNA damage responses.

The Basic Cleft of RPA70N Binds Multiple Checkpoint Proteins, Including RAD9, To Regulate ATR Signaling

The basic cleft of the RPA70 N-terminal OB-fold domain binds multiple checkpoint proteins, including RAD9, to promote ATR signaling, and is found to be a key determinant of checkpoint activation.

Direct binding to RPA-coated ssDNA allows recruitment of the ATR activator TopBP1 to sites of DNA damage

Protein binding assays and functional studies in Xenopus egg extracts supply a mechanism for how the critical ATR activator, TopBP1, senses DNA damage and stalled replication forks to initiate assembly of checkpoint signaling complexes.
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