Phosphatidyl inositol 3-kinase-like serine/threonine protein kinases (PIKKs) are required for DNA damage-induced phosphorylation of the 32 kDa subunit of replication protein A at threonine 21

Block, Wesley D.

doi:10.1093/nar/gkh265

Cited by 102 publications

(109 citation statements)

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“…Interestingly, autophagy-like morphological changes were observed , but other autophagy-like features were missing. Notably, ATM is reported to be necessary for the self-renewal of mouse haematopoietic stem cells by regulating oxidative stress (Block et al, 2004). Whether the defect of cycle G 1 -S phase progression in normal urothelial cells results in some kind of cell re-programming needs further examination.…”

Section: Chapter 6 Discussionmentioning

confidence: 99%

“…This DNA damage-triggered RPA hyper-phophorylation is considered to be activated by phosphatidylinositol 3-kinase-related kinases (PIKKs) family including ataxia-telangiectasia mutated (ATM), ataxia-and Rad3-related (ATR) and DNA-dependent protein kinase (DNA-PK) (Block et al, 2004).…”

Section: )mentioning

confidence: 99%

“…Notably ATM was found to play a role in regulating oxidative stress, which is necessary for the self-renewal of mouse haematopoietic stem cells (Block et al, 2004). Replication stress or DNA damage is increased during o ncogenic transformation, which makes them more dependent upon DNA damage response pathways for cell survival (Bartkova et al, 2006;Bester et al, 2011;Vafa et al, 2002) .…”

Section: -H2axmentioning

confidence: 99%

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Differential response of normal and malignant urothelial cells to CHK1 and ATM inhibitors

2014

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Section: Chapter 6 Discussionmentioning

confidence: 99%

Section: )mentioning

confidence: 99%

Section: -H2axmentioning

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Differential response of normal and malignant urothelial cells to CHK1 and ATM inhibitors

2014

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“…The Thr 21 and Ser 33 residues are consensus sites for phosphatidylinositol 3-kinase-like kinase (PIKK) family members (ATM, ATR, and DNA-PK) that signal the presence of DNA damage and replication stress. Under DNA damage conditions, the phosphorylation of Thr 21 is apparently catalyzed by ATM, DNA-PK, and probably ATR (22,23 . Others have also shown the involvement of DNA-PK in supporting RPA2 hyperphosphorylation (25,26).…”

mentioning

confidence: 99%

“…Cis-phosphorylation follows a preferred pathway. (That is, the initial modification of Ser 33 by ATR stimulates subsequent phosphorylation of Cdk sites Ser 23 and Ser 29 ). These events then facilitate modification of Thr 21 and extreme N-terminal sites Ser 4 and Ser 8 , probably by DNA-PK.…”

mentioning

confidence: 99%

Sequential and Synergistic Modification of Human RPA Stimulates Chromosomal DNA Repair

Anantha

Vassin

Borowiec

2007

Journal of Biological Chemistry

150

211

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The activity of human replication protein A (RPA) in DNA replication and repair is regulated by phosphorylation of the middle RPA2 subunit. It has previously been shown that up to nine different N-terminal residues are modified in vivo and in response to genotoxic stress. Using a novel antibody against phospho-Ser 29 , a moiety formed by cyclin-Cdk, we observed that RPA2 was phosphorylated during mitosis in nonstressed cells. Robust phosphorylation of Ser 29 was also seen in interphase cells following treatment with the DNA-damaging agent camptothecin, a rare example of stress stimulating the modification of a repair factor by cyclin-Cdk. RPA2 phosphorylation is regulated both in cis and trans. Cis-phosphorylation follows a preferred pathway. (That is, the initial modification of Ser 33 by ATR stimulates subsequent phosphorylation of Cdk sites Ser 23 and Ser 29 ). These events then facilitate modification of Thr 21 and extreme N-terminal sites Ser 4 and Ser 8 , probably by DNA-PK. Our data also indicate that the phosphorylation of one RPA molecule can influence the phosphorylation of other RPA molecules in trans. Cells in which endogenous RPA2 was "replaced" with a double S23A/S29A-RPA2 mutant were seen to have an abnormal cell cycle distribution both in normal and in stressed cells. Such cells also showed aberrant DNA damage-dependent RPA foci and had persistent staining of ␥H2AX following DNA damage. Our data indicate that RPA phosphorylation facilitates chromosomal DNA repair. We postulate that the RPA phosphorylation pattern provides a means to regulate the DNA repair pathway utilized.Replication protein A (RPA) 2 is a heterotrimeric singlestranded DNA-binding factor that is critical for the "three Rs" of eukaryotic DNA enzymology: DNA replication, DNA recombination, and DNA repair (1, 2). For DNA replication, the study of cellular and viral model systems demonstrates that RPA is needed both for origin denaturation and replication elongation, in the latter case to facilitate the switch from DNA polymerase ␣ to DNA polymerase ␦ during Okazaki fragment synthesis (3). RPA acts in homologous recombination (HR) to stimulate DNA annealing using physical interactions with Rad52 (4 -7) and in HR-mediated DNA repair, probably employing specific interactions with BRCA2 (8, 9). RPA is a required factor in both the nucleotide excision (10, 11) and mismatch repair pathways (12, 13) and in somatic hypermutation (14). Because of these many roles, it is of significant interest to understand the mechanisms that regulate RPA activity.Of the ϳ70-kDa (RPA1), 30-kDa (RPA2), and 14-kDa (RPA3) subunits, human RPA is subject to extensive phosphorylation on RPA2 (2) and at one RPA1 site (15). The N-terminal 33 residues of RPA2 undergo both cell cycle-and stress-dependent phosphorylation on approximately nine sites (Fig. 1A), which are thought to exist in an unstructured conformation (16,17). Ser 23 and Ser 29 are constitutively modified during mitosis by cyclin B-Cdk1 (18, 19) and have been suggested to be partially modified beginni...

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DNA topoisomerase II‐dependent control of the cell cycle progression in root meristems of Allium cepa

Żabka¹,

Polit²,

Bernasińska³

et al. 2013

Cell Biology International

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The catalytic ability of DNA topoisomerases (Topo) to generate short-term DNA breaks allow these enzymes to play crucial functions in managing DNA topology during S-phase replication, transcription, and chromatin-remodelling processes required to achieve commitment for the onset and transition through mitosis. Our experiments on root meristem cells of onion (Allium cepa) were designed to gain insight into the contribution of Topo II to plant-specific progression throughout interphase and mitosis. Irrespective of the position of the cell in interphase, the immunofluorescence of Topo II revealed similar nuclear labelling pattern with well defined signals dispersed in the nucleoplasm and the cortical zone of the nucleolus. Only weak labelling was detected in metaphase and anaphase chromosomes. Experiments with two potent anti-Topo II agents, doxorubicin (DOX, an anthracycline) and a bisdioxopiperazine derivative, ICRF-193, suggest that the inhibition-mediated increase in Topo II immunofluorescence may represent a compensatory mechanism, by which an up-regulated expression of the enzyme tends to counteract the drug-induced loss of indispensable catalytic and relaxation functions. γ-H2AX immunolabelling seems to indicate that both DOX- and ICRF-193-induced alterations in cell cycle progression reflect primarily the activity of the G2/M DNA damage checkpoint. Our findings provide evidence for the plant-specific cell cycle control mechanism induced by Topo II inhibitors under DNA stress conditions.

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Phosphatidyl inositol 3-kinase-like serine/threonine protein kinases (PIKKs) are required for DNA damage-induced phosphorylation of the 32 kDa subunit of replication protein A at threonine 21

Cited by 102 publications

References 51 publications

Differential response of normal and malignant urothelial cells to CHK1 and ATM inhibitors

Differential response of normal and malignant urothelial cells to CHK1 and ATM inhibitors

Sequential and Synergistic Modification of Human RPA Stimulates Chromosomal DNA Repair

DNA topoisomerase II‐dependent control of the cell cycle progression in root meristems of Allium cepa

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