scholarly journals Regulation of Pkc1 Hyper-Phosphorylation by Genotoxic Stress

2021 ◽  
Vol 7 (10) ◽  
pp. 874
Author(s):  
Li Liu ◽  
Jiri Veis ◽  
Wolfgang Reiter ◽  
Edwin Motari ◽  
Catherine E. Costello ◽  
...  
Keyword(s):  
Dna Damage ◽  
Cell Wall ◽  
Protein Kinase ◽  
Transcriptional Response ◽  
Genotoxic Stress ◽  
Telomere Maintenance ◽  
Phosphorylation Sites ◽  
Casein Kinase 1 ◽  
Checkpoint Kinases ◽  
Radiation Repair

The cell wall integrity (CWI) signaling pathway is best known for its roles in cell wall biogenesis. However, it is also thought to participate in the response to genotoxic stress. The stress-activated protein kinase Mpk1 (Slt2, is activated by DNA damaging agents through an intracellular mechanism that does not involve the activation of upstream components of the CWI pathway. Additional observations suggest that protein kinase C (Pkc1), the top kinase in the CWI signaling cascade, also has a role in the response to genotoxic stress that is independent of its recognized function in the activation of Mpk1. Pkc1 undergoes hyper-phosphorylation specifically in response to genotoxic stress; we have found that this requires the DNA damage checkpoint kinases Mec1 (Mitosis Entry Checkpoint) and Tel1 (TELomere maintenance), but not their effector kinases. We demonstrate that the casein kinase 1 (CK1) ortholog, Hrr25 (HO and Radiation Repair), previously implicated in the DNA damage transcriptional response, associates with Pkc1 under conditions of genotoxic stress. We also found that the induced association of Hrr25 with Pkc1 requires Mec1 and Tel1, and that Hrr25 catalytic activity is required for Pkc1-hyperphosphorylation, thereby delineating a pathway from the checkpoint kinases to Pkc1. We used SILAC mass spectrometry to identify three residues within Pkc1 the phosphorylation of which was stimulated by genotoxic stress. We mutated these residues as well as a collection of 13 phosphorylation sites within the regulatory domain of Pkc1 that fit the consensus for CK1 sites. Mutation of the 13 Pkc1 phosphorylation sites blocked hyper-phosphorylation and diminished RNR3 (RiboNucleotide Reductase) basal expression and induction by genotoxic stress, suggesting that Pkc1 plays a role in the DNA damage transcriptional response.

scholarly journals DNA damage shifts circadian clock time via Hausp-dependent Cry1 stabilization

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Stephanie J Papp ◽  
Anne-Laure Huber ◽  
Sabine D Jordan ◽  
Anna Kriebs ◽  
Madelena Nguyen ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Circadian Clock ◽  
Transcriptional Response ◽  
Genotoxic Stress ◽  
Genomic Integrity ◽  
Clock Time ◽  
Dna Repair Enzymes ◽  
Repair Enzymes ◽  
Specific Protease

The circadian transcriptional repressors cryptochrome 1 (Cry1) and 2 (Cry2) evolved from photolyases, bacterial light-activated DNA repair enzymes. In this study, we report that while they have lost DNA repair activity, Cry1/2 adapted to protect genomic integrity by responding to DNA damage through posttranslational modification and coordinating the downstream transcriptional response. We demonstrate that genotoxic stress stimulates Cry1 phosphorylation and its deubiquitination by Herpes virus associated ubiquitin-specific protease (Hausp, a.k.a Usp7), stabilizing Cry1 and shifting circadian clock time. DNA damage also increases Cry2 interaction with Fbxl3, destabilizing Cry2. Thus, genotoxic stress increases the Cry1/Cry2 ratio, suggesting distinct functions for Cry1 and Cry2 following DNA damage. Indeed, the transcriptional response to genotoxic stress is enhanced in Cry1−/− and blunted in Cry2−/− cells. Furthermore, Cry2−/− cells accumulate damaged DNA. These results suggest that Cry1 and Cry2, which evolved from DNA repair enzymes, protect genomic integrity via coordinated transcriptional regulation.

scholarly journals A Role for Saccharomyces cerevisiae Chk1p in the Response to Replication Blocks

2004 ◽  
Vol 15 (9) ◽  
pp. 4051-4063 ◽  
Author(s):  
Kaila L. Schollaert ◽  
Julie M. Poisson ◽  
Jennifer S. Searle ◽  
Jennifer A. Schwanekamp ◽  
Craig R. Tomlinson ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dna Damage ◽  
Transcriptional Response ◽  
S Phase ◽  
Yeast Cells ◽  
Dna Damage Checkpoint ◽  
Checkpoint Kinases ◽  
Checkpoint Pathway ◽  
Dna Replication And Repair ◽  
S Phase Checkpoint

Replication blocks and DNA damage incurred during S phase activate the S-phase and intra-S-phase checkpoint responses, respectively, regulated by the Atrp and Chk1p checkpoint kinases in metazoans. In Saccharomyces cerevisiae, these checkpoints are regulated by the Atrp homologue Mec1p and the kinase Rad53p. A conserved role of these checkpoints is to block mitotic progression until DNA replication and repair are completed. In S. cerevisiae, these checkpoints include a transcriptional response regulated by the kinase Dun1p; however, dun1Δ cells are proficient for the S-phase-checkpoint-induced anaphase block. Yeast Chk1p kinase regulates the metaphase-to-anaphase transition in the DNA-damage checkpoint pathway via securin (Pds1p) phosphorylation. However, like Dun1p, yeast Chk1p is not required for the S-phase-checkpoint-induced anaphase block. Here we report that Chk1p has a role in the intra-S-phase checkpoint activated when yeast cells replicate their DNA in the presence of low concentrations of hydroxyurea (HU). Chk1p was modified and Pds1p was transiently phosphorylated in this response. Cells lacking Dun1p were dependent on Chk1p for survival in HU, and chk1Δ dun1Δ cells were defective in the recovery from replication interference caused by transient HU exposure. These studies establish a relationship between the S-phase and DNA-damage checkpoint pathways in S. cerevisiae and suggest that at least in some genetic backgrounds, the Chk1p/securin pathway is required for the recovery from stalled or collapsed replication forks.

scholarly journals Protein Kinase C δ Activates Topoisomerase IIα To Induce Apoptotic Cell Death in Response to DNA Damage

2006 ◽  
Vol 26 (9) ◽  
pp. 3414-3431 ◽  
Author(s):  
Kiyotsugu Yoshida ◽  
Tomoko Yamaguchi ◽  
Hirokuni Shinagawa ◽  
Naoe Taira ◽  
Keiichi I. Nakayama ◽  
...  
Keyword(s):  
Dna Damage ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Cell Fate ◽  
Topoisomerase Ii ◽  
Apoptotic Cell ◽  
Genotoxic Stress ◽  
Topoisomerase Iiα ◽  
Kinase C ◽  
Topological State

ABSTRACT DNA topoisomerase II is an essential nuclear enzyme that modulates DNA processes by altering the topological state of double-stranded DNA. This enzyme is required for chromosome condensation and segregation; however, the regulatory mechanism of its activation is largely unknown. Here we demonstrate that topoisomerase IIα is activated in response to genotoxic stress. Concomitant with the activation, the expression of topoisomerase IIα is increased following DNA damage. The results also demonstrate that the proapoptotic kinase protein kinase C δ (PKCδ) interacts with topoisomerase IIα. This association is in an S-phase-specific manner and is required for stabilization and catalytic activation of topoisomerase IIα in response to DNA damage. Conversely, inhibition of PKCδ activity attenuates DNA damage-induced activation of topoisomerase IIα. Finally, aberrant activation of topoisomerase IIα by PKCδ is associated with induction of apoptosis upon exposure to genotoxic agents. These findings indicate that PKCδ regulates topoisomerase IIα and thereby cell fate in the genotoxic stress response.

scholarly journals Yeast Mpk1 Cell Wall Integrity Mitogen-activated Protein Kinase Regulates Nucleocytoplasmic Shuttling of the Swi6 Transcriptional Regulator

2010 ◽  
Vol 21 (9) ◽  
pp. 1609-1619 ◽  
Author(s):  
Ki-Young Kim ◽  
Andrew W. Truman ◽  
Stefanie Caesar ◽  
Gabriel Schlenstedt ◽  
David E. Levin
Keyword(s):  
Cell Wall ◽  
Protein Kinase ◽  
Transcriptional Activation ◽  
Transcriptional Response ◽  
Wall Stress ◽  
Cell Wall Integrity ◽  
Mitogen Activated Protein Kinase ◽  
Nucleocytoplasmic Shuttling ◽  
Nuclear Entry ◽  
Mitogen Activated Protein

The yeast SBF transcription factor is a heterodimer comprised of Swi4 and Swi6 that has a well defined role in cell cycle-specific transcription. SBF serves a second function in the transcriptional response to cell wall stress in which activated Mpk1 mitogen-activated protein kinase of the cell wall integrity signaling pathway forms a complex with Swi4, the DNA binding subunit of SBF, conferring upon Swi4 the ability to bind DNA and activate transcription of FKS2. Although Mpk1–Swi4 complex formation and transcriptional activation of FKS2 does not require Mpk1 catalytic activity, Swi6 is phosphorylated by Mpk1 and must be present in the Mpk1-Swi4 complex for transcriptional activation of FKS2. Here, we find that Mpk1 regulates Swi6 nucleocytoplasmic shuttling in a biphasic manner. First, formation of the Mpk1-Swi4 complex recruits Swi6 to the nucleus for transcriptional activation. Second, Mpk1 negatively regulates Swi6 by phosphorylation on Ser238, which inhibits nuclear entry. Ser238 neighbors a nuclear localization signal (NLS) whose function is blocked by phosphorylation at Ser238 in a manner similar to the regulation by Cdc28 of another Swi6 NLS, revealing a mechanism for the integration of multiple signals to a single endpoint. Finally, the Kap120 β-importin binds the Mpk1-regulated Swi6 NLS but not the Cdc28-regulated NLS.

scholarly journals Protein Kinase C δ Induces Transcription of the TP53 Tumor Suppressor Gene by Controlling Death-Promoting Factor Btf in the Apoptotic Response to DNA Damage

2007 ◽  
Vol 27 (24) ◽  
pp. 8480-8491 ◽  
Author(s):  
Hanshao Liu ◽  
Zheng-Guang Lu ◽  
Yoshio Miki ◽  
Kiyotsugu Yoshida
Keyword(s):  
Dna Damage ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Tumor Suppressor ◽  
Gene Transcription ◽  
Core Promoter ◽  
Genotoxic Stress ◽  
Tp53 Gene ◽  
Transcriptional Level ◽  
Kinase C

ABSTRACT Expression of the TP53 tumor suppressor is tightly controlled for its ability to function as a critical regulator of cell growth, proliferation, and death in response to DNA damage. However, little is known about the mechanisms and contributions of the transcriptional regulation of TP53. Here we report that protein kinase C δ (PKCδ), a ubiquitously expressed member of the novel subfamily of PKC isoforms, transactivates TP53 expression at the transcriptional level. Reporter assays demonstrated that PKCδ induces the promoter activity of TP53 through the TP53 core promoter element (CPE-TP53) and that such induction is enhanced in response to DNA damage. The results also demonstrate that, upon exposure to genotoxic stress, PKCδ activates and interacts with the death-promoting transcription factor Btf to co-occupy CPE-TP53. Inhibition of PKCδ activity decreases the affinity of Btf for CPE-TP53, thereby reducing TP53 expression at both the mRNA and the protein levels. In concert with these results, we show that disruption of Btf-mediated TP53 gene transcription by RNA interference leads to suppression of TP53-mediated apoptosis following genotoxic stress. These findings provide evidence that activation of TP53 gene transcription by PKCδ triggers TP53-dependent apoptosis in response to DNA damage.

scholarly journals SMG-1 as a Promising Tumor Suppressor in the Management of Cancers

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Nam SW ◽  
Keyword(s):  
Dna Damage ◽  
Protein Kinase ◽  
Mammalian Target Of Rapamycin ◽  
Genotoxic Stress ◽  
Loss Of Function ◽  
Dna Double Strand Breaks ◽  
Calculated Molecular Mass ◽  
C Elegans ◽  
Acid Protein ◽  
Nonsense Mediated Mrna Decay

SMG-1 (Suppressor of Morphogenesis in Genitalia-1) is an evolutionally conserved serine/threonine-protein kinase and belongs Phosphatidylinositol-3-Kinase (PI3K) related kinases (PIKKs) that include Ataxia Telangiectasia Mutated (ATM), ATM and Rad3 Related (ATR), Mammalian Target of Rapamycin (mTOR), DNADependent Protein Kinase Catalytic Subunit (DNA-PKcs) and Transformation/Transcription Domain-Associated Protein (TRRAP) [1]. The deduced 3,521-amino acid protein has a calculated molecular mass of 410kD [2]. PIKKs have diverse functions. For example, ATM, ATR and DNA-PKcs are involved in the response to DNA damage. ATM and DNA-PKcs respond to DNA Double Strand Breaks (DSBs) and ATR to DNA replication blockers or formation of long stretches of single strand DNA [3]. mTOR is a nutrient-regulated kinase that controls a wide variety of pathways involved in metabolism and cell growth [4]. TRRAP functions as part of a multiprotein co-activator complex which is involved with the transcriptional activity of c-Myc and other transcriptional factors [5]. SMG-1 is a part of the mRNA surveillance complex that regulates Nonsense-Mediated mRNA Decay (NMD) [6]. SMG-1 was firstly reported as a member of the informational suppression in Caenorhabditis elegans (C. elegans) which affected several mRNA processes in 1989 [7]. Pulak et al. reported that loss of function mutations affecting seven C. elegans smg genes eliminates NMD [8] and later demonstrated that smg- 1 kinase activity was essential for NMD [9]. In 2001, Deming et al. reported a partial sequence of human SMG-1 as C. elegans SMG-1 related protein [10]. Yamashita et al. also reported the full-length sequence for human smg-1 which encoded a 3657 aa protein that was a novel PIKK and showed the involvement of SMG1 in mammalian NMD [11]. In 2004, Brumbaugh et al. reported the activation of SMG-1 by DNA damage and involvement of SMG-1 in genotoxic stress-induced phosphorylation of P53 [2]. Besides NMD, SMG- 1 roles as a protective agency in genotoxic stress such as radiation, tumor proliferation, and apoptosis. I will briefly summarize the roles of SMG-1 related with NMD and others in this paper.

scholarly journals P-TEFb activation by RBM7 shapes a pro-survival transcriptional response to genotoxic stress

2018 ◽  
Author(s):  
Andrii Bugai ◽  
Alexandre J.C. Quaresma ◽  
Caroline C. Friedel ◽  
Tina Lenasi ◽  
Christopher R. Sibley ◽  
...  
Keyword(s):  
Dna Damage ◽  
Rna Polymerase Ii ◽  
Cell Fate ◽  
Rna Binding ◽  
Transcriptional Response ◽  
Genotoxic Stress ◽  
Binding Motif ◽  
Pol Ii ◽  
Small Nuclear Ribonucleoprotein ◽  
Stress Dependent

SUMMARYCellular DNA damage response (DDR) involves dramatic transcriptional alterations, the mechanisms of which remain ill-defined. Given the centrality of RNA polymerase II (Pol II) promoter-proximal pause release in transcriptional control, we evaluated its importance in DDR. Here we show that following genotoxic stress, the RNA-binding motif protein 7 (RBM7) stimulates Pol II elongation and promotes cell viability by activating the positive transcription elongation factor b (P-TEFb). This is mediated by genotoxic stress-enhanced binding of RBM7 to 7SK snRNA (7SK), the scaffold of the 7SK small nuclear ribonucleoprotein (7SK snRNP) which inhibits P-TEFb. In turn, P-TEFb relocates from 7SK snRNP to chromatin to induce transcription of short units including key DDR genes and multiple classes of non-coding RNAs. Critically, interfering with RBM7 or P-TEFb provokes cellular hypersensitivity to DNA damage-inducing agents through activation of apoptotic program. By alleviating the inhibition of P-TEFb, RBM7 thus facilitates Pol II elongation to enable a pro-survival transcriptional response that is crucial for cell fate upon genotoxic insult. Our work uncovers a new paradigm in stress-dependent control of Pol II pause release, and offers the promise for designing novel anti-cancer interventions using RBM7 and P-TEFb antagonists in combination with DNA-damaging chemotherapeutics.

scholarly journals Rad53 Phosphorylation Site Clusters Are Important for Rad53 Regulation and Signaling

2003 ◽  
Vol 23 (17) ◽  
pp. 6300-6314 ◽  
Author(s):  
Soo-Jung Lee ◽  
Marc F. Schwartz ◽  
Jimmy K. Duong ◽  
David F. Stern
Keyword(s):  
Dna Damage ◽  
Protein Kinase ◽  
Kinase Activity ◽  
Phosphorylation Site ◽  
Phosphorylation Sites ◽  
Dependent Manner ◽  
Amino Terminal ◽  
Rad53 Kinase ◽  
Substitution Mutations

ABSTRACT Budding yeast Rad53 is an essential protein kinase that is phosphorylated and activated in a MEC1- and TEL1-dependent manner in response to DNA damage. We studied the role of Rad53 phosphorylation through mutation of consensus phosphorylation sites for upstream kinases Mec1 and Tel1. Alanine substitution of the Rad53 amino-terminal TQ cluster region reduced viability and impaired checkpoint functions. These substitution mutations spared the basal interaction with Asf1 and the DNA damage-induced interactions with Rad9. However, they caused a decrease in DNA damage-induced Rad53 kinase activity and an impaired interaction with the protein kinase Dun1. The Dun1 FHA (Forkhead-associated) domain recognized the amino-terminal TQ cluster of Rad53 after DNA damage or replication blockade. Thus, the phosphorylation of Rad53 by upstream kinases is important not only for Rad53 activation but also for creation of an interface between Rad53 and Dun1.

scholarly journals Continuous transcription initiation guarantees robust repair of transcribed genes and regulatory regions in response to DNA damage

2019 ◽  
Author(s):  
Anastasios Liakos ◽  
Dimitris Konstantopoulos ◽  
Matthieu D. Lavigne ◽  
Maria Fousteri
Keyword(s):  
Dna Damage ◽  
Rna Polymerase Ii ◽  
Transcription Initiation ◽  
De Novo ◽  
Transcriptional Response ◽  
Genotoxic Stress ◽  
Chromatin Accessibility ◽  
Initiation Rate ◽  
Pol Ii ◽  
Active Genes

ABSTRACTInhibition of RNA synthesis caused by DNA damage-impaired RNA polymerase II (Pol II) elongation is found to conceal a local increase in de novo transcription, slowly progressing from Transcription Start Sites (TSSs) to gene ends. Although associated with accelerated repair of Pol II-encountered lesions and limited mutagenesis, it is still unclear how this mechanism is maintained during recovery from genotoxic stress. Here we uncover a surprising widespread gain in chromatin accessibility and preservation of the active histone mark H3K27ac after UV-irradiation. We show that the concomitant increase in Pol II release from promoter-proximal pause (PPP) sites of most active genes, PROMoter uPstream Transcripts (PROMPTs) and enhancer RNAs (eRNAs) favors unrestrained initiation, as demonstrated by the synthesis of short nascent RNAs, including TSS-associated RNAs (start-RNAs). In accordance, drug-inhibition of the transition into elongation replenished the post-UV reduced levels of pre-initiating pol II at TSSs. Continuous engagement of new Pol II thus ensures maximal transcription-driven DNA repair of active genes and non-coding regulatory loci. Together, our results reveal an unanticipated layer regulating the UV-triggered transcriptional-response and provide physiologically relevant traction to the emerging concept that transcription initiation rate is determined by pol II pause-release dynamics.

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