Format

Send to

Choose Destination
Nucleic Acids Res. 2015 May 26;43(10):4962-74. doi: 10.1093/nar/gkv369. Epub 2015 Apr 27.

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

Author information

1
National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi-110067, India.
2
National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi-110067, India sandeep@nii.res.in.

Abstract

The primary eukaryotic single-stranded DNA-binding protein, Replication protein A (RPA), binds to single-stranded DNA at the sites of DNA damage and recruits the apical checkpoint kinase, ATR via its partner protein, ATRIP. It has been demonstrated that absence of RPA incapacitates the ATR-mediated checkpoint response. We report that in the absence of RPA, human single-stranded DNA-binding protein 1 (hSSB1) and its partner protein INTS3 form sub-nuclear foci, associate with the ATR-ATRIP complex and recruit it to the sites of genomic stress. The ATRIP foci formed after RPA depletion are abrogated in the absence of INTS3, establishing that hSSB-INTS3 complex recruits the ATR-ATRIP checkpoint complex to the sites of genomic stress. Depletion of homologs hSSB1/2 and INTS3 in RPA-deficient cells attenuates Chk1 phosphorylation, indicating that the cells are debilitated in responding to stress. We have identified that TopBP1 and the Rad9-Rad1-Hus1 complex are essential for the alternate mode of ATR activation. In summation, we report that the single-stranded DNA-binding protein complex, hSSB1/2-INTS3 can recruit the checkpoint complex to initiate ATR signaling.

PMID:
25916848
PMCID:
PMC4446429
DOI:
10.1093/nar/gkv369
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Silverchair Information Systems Icon for PubMed Central
Loading ...
Support Center