Role of extracellular signal-regulated kinase (ERK) signaling in nucleotide excision repair and genotoxicity in response to As(III) and Pb(II)

Arsenic and lead can induce genetic injuries and epigenetic signaling pathways in cultured mammalian cells. To test whether signaling pathways affect the extent of genetic injuries, we explored the impacts of extracellular signal-regulated kinase 1 and 2 (ERK) on nucleotide excision repair (NER), cytotoxicity, and genotoxicity following sodium arsenite [As(III)] and lead acetate [Pb(II)]. Sustained ERK activation was observed in human cells exposed to As(III) and Pb(II). As(III) inhibited the cellular NER synthesis capability; conversely, Pb(II) stimulated it. ERK activation contributed to the As(III)-induced NER inhibition and micronucleus formation. In contrast, this signal was required for inducing cellular NER activity and preventing mutagenesis following Pb(II). ERK activation by Pb(II) was dependent on protein kinase C (PKCα) that also exhibited anti-mutagenicity. Enforced expression of ERK signaling markedly elevated the cellular NER activity, which was suppressed by As(III). Nonetheless, ERK activation could counteract the cytotoxicity caused by these two metals. Together, the results indicate that pro-survival ERK signaling exhibits dual and opposing impacts on NER process following As(III) and Pb(II) exposures. The findings also suggest that ERK is an important epigenetic signaling in the determination of metal genotoxicity.

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GENES CONTROLLING NUCLEOTIDE EXCISION REPAIR IN MAMMALIAN CELLS

Congress Proceedings ◽

10.1016/b978-0-12-168562-1.50045-8 ◽

1992 ◽

pp. 235-238

Author(s):

G. Weeda ◽

C. Troelstra ◽

W. Vermeulen ◽

D. Bootsma ◽

J.H.J. Hoeijmakers ◽

...

Keyword(s):

Nucleotide Excision Repair ◽

Mammalian Cells ◽

Excision Repair ◽

Nucleotide Excision

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Role of Phosphoinositide 3-Kinase and Endocytosis in Nerve Growth Factor-Induced Extracellular Signal-Regulated Kinase Activation via Ras and Rap1

Molecular and Cellular Biology ◽

10.1128/mcb.20.21.8069-8083.2000 ◽

2000 ◽

Vol 20 (21) ◽

pp. 8069-8083 ◽

Cited By ~ 162

Author(s):

Randall D. York ◽

Derek C. Molliver ◽

Savraj S. Grewal ◽

Paula E. Stenberg ◽

Edwin W. McCleskey ◽

...

Keyword(s):

Nerve Growth Factor ◽

Growth Factor ◽

Map Kinase ◽

Pc12 Cells ◽

Erk Signaling ◽

Nerve Growth ◽

Erk Activation ◽

Extracellular Signal Regulated Kinase ◽

Extracellular Signal ◽

Phosphoinositide 3 Kinase

ABSTRACT Neurotrophins promote multiple actions on neuronal cells including cell survival and differentiation. The best-studied neurotrophin, nerve growth factor (NGF), is a major survival factor in sympathetic and sensory neurons and promotes differentiation in a well-studied model system, PC12 cells. To mediate these actions, NGF binds to the TrkA receptor to trigger intracellular signaling cascades. Two kinases whose activities mediate these processes include the mitogen-activated protein (MAP) kinase (or extracellular signal-regulated kinase [ERK]) and phosphoinositide 3-kinase (PI3-K). To examine potential interactions between the ERK and PI3-K pathways, we studied the requirement of PI3-K for NGF activation of the ERK signaling cascade in dorsal root ganglion cells and PC12 cells. We show that PI3-K is required for TrkA internalization and participates in NGF signaling to ERKs via distinct actions on the small G proteins Ras and Rap1. In PC12 cells, NGF activates Ras and Rap1 to elicit the rapid and sustained activation of ERKs respectively. We show here that Rap1 activation requires both TrkA internalization and PI3-K, whereas Ras activation requires neither TrkA internalization nor PI3-K. Both inhibitors of PI3-K and inhibitors of endocytosis prevent GTP loading of Rap1 and block sustained ERK activation by NGF. PI3-K and endocytosis may also regulate ERK signaling at a second site downstream of Ras, since both rapid ERK activation and the Ras-dependent activation of the MAP kinase kinase kinase B-Raf are blocked by inhibition of either PI3-K or endocytosis. The results of this study suggest that PI3-K may be required for the signals initiated by TrkA internalization and demonstrate that specific endocytic events may distinguish ERK signaling via Rap1 and Ras.

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Proteins that participate in nucleotide excision repair of DNA in mammalian cells

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.1995.0011 ◽

1995 ◽

Vol 347 (1319) ◽

pp. 69-74 ◽

Cited By ~ 12

Keyword(s):

Nucleotide Excision Repair ◽

Mammalian Cells ◽

Excision Repair ◽

Binding Activity ◽

Main Process ◽

Base Pairs ◽

Inherited Disorders ◽

Dna Binding Activity ◽

Nucleotide Excision ◽

Repair Defect

The most versatile strategy for repair of damage to DNA, and the main process for repair of uv-induced damage, is nucleotide excision repair. In mammalian cells, the complete mechanism involves more than 20 polypeptides, and defects in many of these are associated with various forms of inherited disorders in humans. The syndrome xeroderma pigmentosum (XP) is associated with mutagen hypersensitivity and increased cancer frequency, and studies of the nucleotide excision repair defect in this disease have been particularly informative. Many of the XP proteins are now being characterized. XPA binds to DNA, with a preference for damaged base pairs. XPC activity is part of a protein complex with single-stranded DNA binding activity. The XPG protein is a nuclease.

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Measurement of DNA base and nucleotide excision repair activities in mammalian cells and tissues using the comet assay – A methodological overview

DNA Repair ◽

10.1016/j.dnarep.2013.07.011 ◽

2013 ◽

Vol 12 (11) ◽

pp. 1007-1010 ◽

Cited By ~ 29

Author(s):

Amaya Azqueta ◽

Sabine A.S. Langie ◽

Jana Slyskova ◽

Andrew R. Collins

Keyword(s):

Comet Assay ◽

Nucleotide Excision Repair ◽

Mammalian Cells ◽

Excision Repair ◽

Dna Base ◽

Nucleotide Excision

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Triple-Helix Formation Induces Recombination in Mammalian Cells via a Nucleotide Excision Repair-Dependent Pathway

Molecular and Cellular Biology ◽

10.1128/mcb.20.3.990-1000.2000 ◽

2000 ◽

Vol 20 (3) ◽

pp. 990-1000 ◽

Cited By ~ 85

Author(s):

A. Fawad Faruqi ◽

Hirock J. Datta ◽

Dana Carroll ◽

Michael M. Seidman ◽

Peter M. Glazer

Keyword(s):

Nucleotide Excision Repair ◽

Mammalian Cells ◽

Triple Helix ◽

Excision Repair ◽

Gene Knockout ◽

Simian Virus 40 ◽

Cos Cells ◽

Helix Formation ◽

Nucleotide Excision ◽

Triple Helix Formation

ABSTRACT The ability to stimulate recombination in a site-specific manner in mammalian cells may provide a useful tool for gene knockout and a valuable strategy for gene therapy. We previously demonstrated that psoralen adducts targeted by triple-helix-forming oligonucleotides (TFOs) could induce recombination between tandem repeats of asupF reporter gene in a simian virus 40 vector in monkey COS cells. Based on work showing that triple helices, even in the absence of associated psoralen adducts, are able to provoke DNA repair and cause mutations, we asked whether intermolecular triplexes could stimulate recombination. Here, we report that triple-helix formation itself is capable of promoting recombination and that this effect is dependent on a functional nucleotide excision repair (NER) pathway. Transfection of COS cells carrying the dual supF vector with a purine-rich TFO, AG30, designed to bind as a third strand to a region between the two mutant supF genes yielded recombinants at a frequency of 0.37%, fivefold above background, whereas a scrambled sequence control oligomer was ineffective. In human cells deficient in the NER factor XPA, the ability of AG30 to induce recombination was eliminated, but it was restored in a corrected subline expressing the XPA cDNA. In comparison, the ability of triplex-directed psoralen cross-links to induce recombination was only partially reduced in XPA-deficient cells, suggesting that NER is not the only pathway that can metabolize targeted psoralen photoadducts into recombinagenic intermediates. Interestingly, the triplex-induced recombination was unaffected in cells deficient in DNA mismatch repair, challenging our previous model of a heteroduplex intermediate and supporting a model based on end joining. This work demonstrates that oligonucleotide-mediated triplex formation can be recombinagenic, providing the basis for a potential strategy to direct genome modification by using high-affinity DNA binding ligands.

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DNA Replication but Not Nucleotide Excision Repair Is Required for UVC-Induced Replication Protein A Phosphorylation in Mammalian Cells

Molecular and Cellular Biology ◽

10.1128/mcb.20.8.2696-2705.2000 ◽

2000 ◽

Vol 20 (8) ◽

pp. 2696-2705 ◽

Cited By ~ 23

Author(s):

Gregory Rodrigo ◽

Sophie Roumagnac ◽

Marc S. Wold ◽

Bernard Salles ◽

Patrick Calsou

Keyword(s):

Dna Damage ◽

Dna Replication ◽

Nucleotide Excision Repair ◽

Mammalian Cells ◽

Excision Repair ◽

Protein A ◽

Replication Protein A ◽

Replication Protein ◽

Dependent Manner ◽

Nucleotide Excision

ABSTRACT Exposure of mammalian cells to short-wavelength light (UVC) triggers a global response which can either counteract the deleterious effect of DNA damage by enabling DNA repair or lead to apoptosis. Several stress-activated protein kinases participate in this response, making phosphorylation a strong candidate for being involved in regulating the cellular damage response. One factor that is phosphorylated in a UVC-dependent manner is the 32-kDa subunit of the single-stranded DNA-binding replication protein A (RPA32). RPA is required for major cellular processes like DNA replication, and removal of DNA damage by nucleotide excision repair (NER). In this study we examined the signal which triggers RPA32 hyperphosphorylation following UVC irradiation in human cells. Hyperphosphorylation of RPA was observed in cells from patients with either NER or transcription-coupled repair (TCR) deficiency (A, C, and G complementation groups of xeroderma pigmentosum and A and B groups of Cockayne syndrome, respectively). This exclude both NER intermediates and TCR as essential signals for RPA hyperphosphorylation. However, we have observed that UV-sensitive cells deficient in NER and TCR require lower doses of UV irradiation to induce RPA32 hyperphosphorylation than normal cells, indicating that persistent unrepaired lesions contribute to RPA phosphorylation. Finally, the results of UVC irradiation experiments on nonreplicating cells and S-phase-synchronized cells emphasize a major role for DNA replication arrest in the presence of UVC lesions in RPA UVC-induced hyperphosphorylation in mammalian cells.

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