The mitogenactivated protein kinase mapk signaling pathway is known to be activated by uvr and herein we identify p38 mapk as a key modulator of these physiologic events. Sustained activation of jnkp38 mapk pathways in response to. In this study, we have found that the p38 mitogenactivated protein kinase mapk plays a key role in the activation of p53 by genotoxic stress when provoked by chemotherapeutic agents. Jojournalurnal tao kinases mediate activation of p38 in. Doramapimod birb 796 doramapimod birb 796 is a pan p38 mapk inhibitor with ic50 of 38 nm, 65 nm, 200 nm and 520 nm for p38. Of note, the involvement of ros and dna damage in the sequential activation of the erk and p38 pathways may not be mutually exclusive, as ros is a known dna damaging. The role of p38 mapk pathway in p53 compromised state and. Hyunjeong eom and jinhee choi school of environmental engineering, college of urban science, university of seoul, 90 jeonnongdong. Crosstalk between atm, p38mapk and shelterin complex. The oxidative dna damage observed was transient, likely due to dna repair. Effect of pbk knockdown on p38 activation after dna damage.
Despite its role in the induction of cell cycle checkpoints in response to dsbs inducing stimuli, little is known about the intracellular distribution of p38 mapk following its activation by dsbs. Hyperproliferative signals generated by activated mekerk may cause hyperreplication of dna, generating dna damage that is known to activate p38 ink4a and induce senescence 9,10,33. Kinase regulates the dna damage response and drives. Pbktopk promotes tumour cell proliferation through p38 mapk. Here we show that the tao kinases mediate the activation of p38 in response to various genotoxic stimuli. Mir34 is induced by p38 mapk mk2 signalling following dna damage. We fail to detect egfr endocytosis or nuclear transport following xray treatment of hela or head and neck cancer cells, despite extensive dna damage. Our previous findings indicated that p38 mapk may be involved in transducing signals leading to cell death. Among intracellular ros, which are able to induce dna damage, h 2 o 2 is known to provoke an appearance of both ssbs and dsbs that can trigger ddr. Atr is recruited to sites of dna damage that are characterised by extended singlestranded ss dna coated with replication protein a rpa. Egf receptor egfr endocytosis is induced by stress in a manner dependent on the p38 mapk family. The kinase ataxia telangiectasia and rad3related protein atr, together with its downstream effector kinases, such as chk1, is one of the master regulators of the dna damage induced response ddr. Effect of silver nanoparticles on mitogenactivated. Sustained activation of jnkp38 mapk pathways in response.
Since a nuclear translocation of p38 mapk upon cell stimulation has not been previously reported, we examined the distribution of p38 mapk in response to other known activators which do not induce dna damage. Dominant negative taos block p38 activation by genotoxic stress. Novel strategies for inhibition of the p38 mapk pathway. The change in phosphorylation status of endogenous xrcc1 after kinase inhibitor treatment prompted us to investigate the. Mechanical stressinduced dna damage and racp38mapk signal. Other mapk pathways activated by radiation include those downstream of death receptors and procaspases, and dna damage signals, including the jnk and p38 mapk pathways. We demonstrate that in nih 3t3 cells, p38 can be potently activated by drugs that cause dna damage by either promoting the formation of dna adducts or inhibiting topoisomerase ii, but not by therapeutically relevant doses of.
Ligand and stresses such as xrays, reportedly promote nuclear trafficking of endocytosed egfr for regulation of gene transcription and dna repair. Thus, it appears that in addition to the atmdependent pathway other not yet established mechanisms activate p38 mapk in response to dna damage. Tao kinases are activated acutely by ionizing radiation, ultraviolet radiation, and hydroxyurea. Pdf the role of p38 mapk pathway in p53 compromised state.
In addition to apoptosis, ika may be able to trigger a form of cell death that is independent of caspaseactivation dotted line. In the following sections we will discuss a series of studies that describes the p38 mapk signaling pathway, dna damage and its response, possible role of p38 mapk pathway in dna damage response ddr in p53 mutated or compromised state, activation of p38 mapk pathway by dysfunctional telomeres and p38 mapk as a possible drug target. The p38 mapk pathway activation is triggered by a variety of stimuli, including uv damage, oxidative stress, and exposure to dna damaging agents, as well as growth factors and cytokines 7,8. Atrdependent activation of p38 mapk is responsible for induction of apoptosis in cdc7depleted cellsbecause the activation of p38 mapk was a specific response to cdc7 depletion, we searched for upstream effectors of the p38 mapk. This study was designed to investigate oxidative dna damage, the activation of atm, a reporter of dna damage, and redoxsensitive signal transduction through mitogenactivated protein kinases mapks by the monomer triethylene glycol dimethacrylate tegdma. To determine if the activation of p38 by dna damage requires taos, dominantnegative tao mutants were expressed in cells that were subsequently treated with hu, uv, or ir to invoke the dna damage response. The intracellular localization of p38 mapk upon activation remains unclear, and may depend on the stimulus. However, in the resistant cells, p38 activity was significantly suppressed, as were markers of dna repair, suggesting that. Pbktopk promotes tumour cell proliferation through p38. Nuclear translocation of p38 mapk does not require its catalytic activity, but is induced by a conformational change of p38 mapk triggered by phosphorylation within the active site.
Through the use of inactive and constitutively active mutants of mkk3 and 6 as well as the p38 inhibitor sb203580, numerous genes regulated by the p38 map kinase pathway have been identified. Mar 29, 2007 here we show that the tao kinases mediate the activation of p38 in response to various genotoxic stimuli. However, how dna damage leads to the activation of p53 is still poorly understood. Nuclear localization of p38 mapk in response to dna damage. Exactly how cisplatin triggers stress kinase pathways is not yet known, nor are the sequential events between cddpinduced oxidative stress, dna damage, jnk p38 activation, and apoptosis. In addition to apoptosis, ika may be able to trigger a form of cell death that is independent of caspase activation. Agnps exposure activates p38 mitogenactivated protein kinase through nuclear factore2related factor2 and nuclear factorkappab signaling pathways, subsequently inducing dna damage, cell cycle arrest and apoptosis. Indeed, depletion or inhibition of mapkactivated protein kinase 2 mk2 and mk3, which function downstream of p38, abolished phosphorylation. We show here that activation of p38 mapk by stimuli that induce dna double strand breaks dsbs, but not other stimuli. Effect of silver nanoparticles on mitogenactivated protein. The p38 mapk signaling activation in colorectal cancer. The increases in activation of the p38 mapk signaling and dna damage response pathways as a result of huinduced oxidative and replication stress suggest that these pathways may serve as intracellular effectors of the embryonic stress response.
While mir34c is induced by p53 following dna damage, we show that in cells lacking p53 this is achieved by an alternative pathway which involves p38 mapk signalling to mk2. Mapk14 is one of the four p38 mapks which play an important role in the cascades of cellular responses evoked by extracellular stimuli such as proinflammatory cytokines or physical stress leading to direct activation of transcription factors. Jul 24, 2017 inhibition of p38 mapk increases xrcc1 recruitment to sites of dna damage. Emerging roles of the p38 mapk and pi3kaktmtor pathways in. To assess the role of p38 mapk pathway in nucleotide excision repair ner, the most versatile dna repair pathway, we determined the. Knockdown of tao kinases inhibits activation of p38 by dna damage to obtain additional evidence that taos are required for p38 activation by dna damage, we used sirna to examine p38 activation by uv, hu and ir in cells with reduced tao expression. Activation of p38 mapk has been reported to be essential for survival of cells in response to stimuli that cause a type of dna damage. Interaction between ros dependent dna damage, mitochondria. The molecular pathways triggered by anticancer drugs that lead to the activation of stress pathways are not well understood. Activation of p38 by atm may act as an alternative pathway in p53 mutated state. Activation and signaling of the p38 map kinase pathway. While chk1 is known to mediate g2 dna damage checkpoint control, p38 was also reported to have an essential function in this checkpoint control. Erk and p38 mapk activities determine sensitivity to pi3k.
Therefore, p38 mapk is required for the synergistic induction of inos by. In response to genotoxic stress, dna damage checkpoints and repair pathways are activated that ensure dna is transmitted intact. Our results imply a direct impact of the p38map kinaseactivated protein kinase 2 mk2 kinase pathway on the cellular response to replicative. Generally, ddr is characterized by activation of ataxiatelangiectasia mutated kinase atm and formation of dnadamage foci, containing.
Persistent activation of the rafmekerk pathway leads to accumulation of ros and dna damage, which activate the stressinduced mkk36 p38 pathway. Ikarugamycin induces dna damage, intracellular calcium. The change in phosphorylation status of endogenous xrcc1 after. The selective nuclear accumulation of p38 mapk in response to dna damage could be a mechanism to facilitate the phosphorylation of p38 mapk nuclear targets for the induction of a g2m cell cycle checkpoint and dna repair. It is clear that the regulation of p38 mapk signaling is complex. In certain contexts, where persistent dna damage is present, p38 can promote cellular senescence and sasp expression 17, 24, 31. Atr, chk1, g2 phase, p38, uv introduction after genotoxic stress dna damage checkpoint and repair pathways are activated that ensure an in tact transmission of the dna hoeijmakers, 2001. Hyperproliferative signals generated by activated mekerk may cause hyperreplication of dna, generating dna damage that is known to activate p38 and induce senescence 9,10,33. The selective nuclear accumulation of p38 mapk in response to dna damage could pose a mechanism to facilitate the phosphorylation of p38 mapk nuclear targets for the induction of a g2m cell cycle checkpoint and dna repair. Of note, the involvement of ros and dna damage in the sequential activation of the erk and p38 pathways may not be mutually exclusive, because ros is a known dna damaging agent. P38 mitogenactivated protein kinases are a class of mitogenactivated protein kinases mapks that are responsive to stress stimuli, such as cytokines, ultraviolet irradiation, heat shock, and osmotic shock, and are involved in cell differentiation, apoptosis and autophagy. Increase, oxidative stress activation, pmk1 p38 mapk leads to increased, dna damage repair february 15, 2017 03.
Tao kinases mediate activation of p38 in response to dna. Mitogenactivated protein kinase 14, also called p38. Hydroxyurea exposure triggers tissuespecific activation. Nuclear localization of p38mapk in response to dna damage. Serinethreonine kinase which acts as an essential component of the map kinase signal transduction pathway. Many cellular stressors like heat shock, osmotic stress, and microtubule depolymerization induce cell cycle arrest via robust activation of p38 map kinase mapk. Atrdependent activation of p38 map kinase is responsible for. Exactly how cisplatin triggers stress kinase pathways is not yet known, nor are the sequential events between cddpinduced oxidative stress, dna damage, jnk p38 activation, and. Activation of different mapk might play an important role in the np toxicity outcomes. Hydroxyurea exposure triggers tissuespecific activation of.
Specifically, it has been shown that oncogenic rasinduced ros cause activation of dna damage responses. Rasmapk signaling functions in oxidative stress, dna. The dna damage response involves a cascade of signalling events, mediated by serinethreonine protein kinases, which act on their substrates to enforce the biological output of the ddr. Thus, nuclear localization of p38 mapk in response to dna damage inducing stimuli is associated with its phosphorylation. Dec 11, 2006 pbktopk promotes tumour cell proliferation through p38 mapk activity and regulation of the dna damage response. Mar 23, 2010 here we show that following etoposideinduced dna damage translation of cmyc is repressed by mir34c via a highly conserved targetsite within the 3. Recruitment of additional proteins, such as rad9containing complexes, are required for activation of atr and subsequent phosphorylation of. Jun 12, 2014 among intracellular ros, which are able to induce dna damage, h 2 o 2 is known to provoke an appearance of both ssbs and dsbs that can trigger ddr. Tao kinases mediate activation of p38 in response to dna damage. Once activated, p38 binds to atp at its atpbinding site adenosine pocket to transfer the. Doramapimod birb 796 doramapimod birb 796 is a panp38 mapk inhibitor with ic50 of 38 nm, 65 nm, 200 nm and 520 nm for p38. Although p38 mapk inhibitor scio469 scios inc, ca, usa alone did not induce significant growth inhibition, it blocked baseline and ps341triggered phosphorylation of p38 mapk.
Generally, ddr is characterized by activation of ataxiatelangiectasia mutated kinase atm and formation of dna damage foci, containing. Tegdmainduced oxidative dna damage and activation of atm. Uvinduced g2 checkpoint depends on p38 mapk and minimal. The p38 mitogenactivated protein kinase augments nucleotide.
Figure 1 oncogenic rasinduced senescence is mediated by sequential activation of the rafmekerk and mkk36 p38 pathways. The selective nuclear accumulation of p38 mapk in response to dna damage could be a mechanism to facilitate the phosphorylation of p38 mapk nuclear targets for the. Research article open access p38 mitogenactivated protein. Dna damage induces the nuclear translocation of p38 mapk. Mice treated withthe p38 mapk inhibitor sb202190 are protected against. Thus, the activation of p38 mapk regardless of the upstream signaling pathway seems to be. During ddr, the mekerk pathway is regularly activated, which contributes to the appropriate activation of ddr checkpoints to inhibit cell division. Damageinduced dna replication stalling relies on mapkactivated. Activation of p38 mitogenactivated protein kinase is. The role of the p38 mapk pathway in the g2 dna damage checkpoint of cancer cells has recently been called into question by the observation that transformed. Pbktopk promotes tumour cell proliferation through p38 mapk activity and regulation of the dna damage response.
Pretreatment with sb202190, a specific inhibitor of p38 mapks, significantly reduced mechanical stressinduced p53 activation. A role for the p38 mitogenactivated protein kinase. To identify potential harmful effects of silver nanoparticles agnps on human health, a comprehensive toxicity assay was conducted on human jurkat t cells, using oxidative stressrelated endpoint. In addition, p38 kinase activation is induced by dna crosslinking agents and is sustained for more than a few days, triggering the apoptotic cascade 33,6264. Emerging roles of the p38 mapk and pi3kaktmtor pathways. Oncogenic ras initially activates the rafmekerk pathway. Stressspecific p38 mapk activation is sufficient to drive. Dna damage, and mediates death, cell differentiation and cell cycle checkpoints. The p38 mapk pathway was shown to be activated in response to agents such as curcumin which induced apoptosis in cisplatinresistant ovarian cancer cells. Ikarugamycin induces dna damage, intracellular calcium increase, p38 map kinase activation and apoptosis in hl60 human promyelocytic leukemia cells.