Protein Phosphatase 2A-Dependent Dephosphorylation of Replication Protein A Is Required for the Repair of DNA Breaks Induced by Replication Stress

Feng, Junjie; Wakeman, Timothy P.; Yong, Sheila T.; Wu, Xiaohua; Kornbluth, Sally; Wang, Xiaofan

doi:10.1128/mcb.00191-09

Cited by 61 publications

(53 citation statements)

References 64 publications

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“…Due to space limitations, this review focuses only on phosphatase-dependent regulation of g-H2AX, ATM, Chk1, Chk2 and p53, factors critically involved in checkpoint signaling. However, other important DDR factors, particularly those in DNA repair pathways, including DNA-PK, RPA2, BRCA1 and so on, are also regulated by Ser/Thr phosphatases (Douglas et al, 2001;Liu et al, 2002;Wechsler et al, 2004;Feng et al, 2009;Mi et al, 2009a;Lee et al, 2010). In most cases, PPs negatively regulate the DNA damage signaling, thus controlling the threshold of DDR activation and promoting DNA damage recovery, consistent with the essential role of protein kinases in activation of the response.…”

Section: Protein Phosphatase-dependent Regulation Of Chk1mentioning

confidence: 89%

Serine/threonine phosphatases in the DNA damage response and cancer

Peng

Maller

2010

Oncogene

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The cellular response to DNA damage is a crucial surveillance mechanism that maintains genomic integrity and prevents cancer progression. Previous studies identified multiple Ser/Thr protein kinases that have pivotal roles in the activation of this response. It is interesting that a growing body of evidence suggests that these kinases and their substrates are under tight modulation by numerous Ser/Thr phosphatases. In this study, we review recent reports that reveal new functions and regulation of these phosphatases. Similar to the kinases in this pathway, phosphatases may also be intimately involved in cancer progression and present valuable targets for cancer therapy.

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Section: Protein Phosphatase-dependent Regulation Of Chk1mentioning

confidence: 89%

Serine/threonine phosphatases in the DNA damage response and cancer

Peng

Maller

2010

Oncogene

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“…It is likely that additional sites are also RFWD3-dependent. In addition to kinases, two phosphatases, PP2A and PP4, have been shown to be required for RPA dephosphorylation (24,33). Loss of these proteins is correlated with impaired recovery from replication block.…”

Section: Discussionmentioning

confidence: 99%

“…It is shown that DNA damage-induced RPA hyperphosphorylation is critical for Rad51 recruitment and HR-mediated repair after replication block but is not essential for IR and I-Sce-I endonuclease-stimulated HR (28). Moreover, recent studies suggest that RPA dephosphorylation is also essential for Rad51-mediated HR and for cells to reenter the cell cycle during recovery from replication block (24,33), further highlighting the importance of regulating RPA2 phosphorylation in a coordinated manner. The RPA-mediated HR repair is also regulated by SUMOylation (34).…”

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confidence: 99%

RING Finger and WD Repeat Domain 3 (RFWD3) Associates with Replication Protein A (RPA) and Facilitates RPA-mediated DNA Damage Response

Liu

Chu

Yucer

et al. 2011

Journal of Biological Chemistry

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DNA damage response is crucial for maintaining genomic integrity and preventing cancer by coordinating the activation of checkpoints and the repair of damaged DNA. Central to DNA damage response are the two checkpoint kinases ATM and ATR that phosphorylate a wide range of substrates. RING finger and WD repeat domain 3 (RFWD3) was initially identified as a substrate of ATM/ATR from a proteomic screen. Subsequent studies showed that RFWD3 is an E3 ubiquitin ligase that ubiquitinates p53 in vitro and positively regulates p53 levels in response to DNA damage. We report here that RFWD3 associates with replication protein A (RPA), a single-stranded DNA-binding protein that plays essential roles in DNA replication, recombination, and repair. Binding of RPA to single-stranded DNA (ssDNA), which is generated by DNA damage and repair, is essential for the recruitment of DNA repair factors to damaged sites and the activation of checkpoint signaling. We show that RFWD3 is physically associated with RPA and rapidly localizes to sites of DNA damage in a RPA-dependent manner. In vitro experiments suggest that the C terminus of RFWD3, which encompass the coiled-coil domain and the WD40 domain, is necessary for binding to RPA. Furthermore, DNA damage-induced phosphorylation of RPA and RFWD3 is dependent upon each other. Consequently, loss of RFWD3 results in the persistent foci of DNA damage marker ␥H2AX and the repair protein Rad51 in damaged cells. These findings suggest that RFWD3 is recruited to sites of DNA damage and facilitates RPA-mediated DNA damage signaling and repair.The cellular response to genotoxic stress initiates multiple signal transduction pathways that include transcription regulation, cell cycle arrest, DNA damage repair, and apoptosis (1, 2). Central to DDR 2 are two checkpoint kinases ATM and ATR that phosphorylate many downstream effectors to execute these functions (3, 4). Identification of key players and the characterization of their molecular functions enable a more thorough understanding of the DDR pathways, which are critical for maintaining genomic integrity. Several recent proteomic screens have drastically expanded the landscape of DDR pathways with the identification of hundreds of putative ATM/ATR substrates (5-7). Recently, we investigated the role of a previously uncharacterized protein, RING finger and WD repeat domain 3 (RFWD3, also known as RNF201 and FLJ10520; GenBank TM number 55159) in DDR (5, 8). Originally identified from a proteomic screen for ATM/ATR substrates, RFWD3 was found phosphorylated at several conserved SQ sites in cells that were treated with ionizing radiation (IR) and replication blocking agents. Subsequent biochemical analysis revealed that RFWD3 can form a complex with MDM2 and p53 and is required for the maintenance of high levels of p53 upon DNA damage induction. The RFWD3 protein contains several well characterized functional domains as well as domains of unknown functions. The N-terminal RING finger domain is a conserved E3 ubiquitin (Ub) ligase domain. In vitro r...

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“…Two different phosphatases seem to regulate RPA dephosphorylation in response to DNA damage [106,122]. Interference with the serine/threonine phosphatase PP2A caused persistent RPA32 phosphorylation and increased sensitivity to HU-induced replication stress.…”

Section: Dephosphorylation Of Rpamentioning

confidence: 99%

RPA-coated single-stranded DNA as a platform for post-translational modifications in the DNA damage response

2014

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The Replication Protein A (RPA) complex is an essential regulator of eukaryotic DNA metabolism. RPA avidly binds to single-stranded DNA (ssDNA) through multiple oligonucleotide/oligosaccharide-binding folds and coordinates the recruitment and exchange of genome maintenance factors to regulate DNA replication, recombination and repair. The RPA-ssDNA platform also constitutes a key physiological signal which activates the master ATR kinase to protect and repair stalled or collapsed replication forks during replication stress. In recent years, the RPA complex has emerged as a key target and an important regulator of post-translational modifications in response to DNA damage, which is critical for its genome guardian functions. Phosphorylation and SUMOylation of the RPA complex, and more recently RPA-regulated ubiquitination, have all been shown to control specific aspects of DNA damage signaling and repair by modulating the interactions between RPA and its partners. Here, we review our current understanding of the critical functions of the RPA-ssDNA platform in the maintenance of genome stability and its regulation through an elaborate network of covalent modifications.

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Protein Phosphatase 2A-Dependent Dephosphorylation of Replication Protein A Is Required for the Repair of DNA Breaks Induced by Replication Stress

Cited by 61 publications

References 64 publications

Serine/threonine phosphatases in the DNA damage response and cancer

Serine/threonine phosphatases in the DNA damage response and cancer

RING Finger and WD Repeat Domain 3 (RFWD3) Associates with Replication Protein A (RPA) and Facilitates RPA-mediated DNA Damage Response

RPA-coated single-stranded DNA as a platform for post-translational modifications in the DNA damage response

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