Read by QxMD icon Read

Dna damage, kap1

Bryndon J Oleson, Aaron Naatz, Sarah C Proudfoot, Chay Teng Yeo, John A Corbett
Nitric oxide is produced at micromolar levels by pancreatic β-cells during exposure to proinflammatory cytokines. While classically viewed as damaging, nitric oxide also activates pathways that promote β-cell survival. We have shown that nitric oxide, in a cell type-selective manner, inhibits the DNA damage response (DDR) and, in doing so, protects β-cells from DNA damage-induced apoptosis. This study explores potential mechanisms by which nitric oxide inhibits DDR signaling. We show that inhibition of DDR signaling (measured by γH2AX formation and the phosphorylation of KAP1) is selective for nitric oxide, as other forms of reactive oxygen/nitrogen species do not impair DDR signaling...
May 2018: Diabetes
Himjyot Jaiswal, Jan Benada, Erik Müllers, Karen Akopyan, Kamila Burdova, Tobias Koolmeister, Thomas Helleday, René H Medema, Libor Macurek, Arne Lindqvist
After DNA damage, the cell cycle is arrested to avoid propagation of mutations. Arrest in G2 phase is initiated by ATM-/ATR-dependent signaling that inhibits mitosis-promoting kinases such as Plk1. At the same time, Plk1 can counteract ATR-dependent signaling and is required for eventual resumption of the cell cycle. However, what determines when Plk1 activity can resume remains unclear. Here, we use FRET-based reporters to show that a global spread of ATM activity on chromatin and phosphorylation of ATM targets including KAP1 control Plk1 re-activation...
July 14, 2017: EMBO Journal
Zdravko J Lorković, Chulmin Park, Malgorzata Goiser, Danhua Jiang, Marie-Therese Kurzbauer, Peter Schlögelhofer, Frédéric Berger
DNA double-strand break (DSB) repair depends on the ataxia telangiectasia mutated (ATM) kinase that phosphorylates the conserved C-terminal SQ motif present in the histone variant H2A.X [1-7]. In constitutive heterochromatin of mammals, DSB repair is delayed and relies on phosphorylation of the proteins HP1 and KAP1 by ATM [2, 8-14]. However, KAP1 is not conserved in plants and the HP1-related protein Like-HP1 (LHP1) is not localized at constitutive heterochromatin [15], suggesting that in plants, alternative mechanisms could be responsible for repair of DSBs in heterochromatin...
April 24, 2017: Current Biology: CB
Fei Xu, Xin Li, Lili Yan, Na Yuan, Yixuan Fang, Yan Cao, Li Xu, Xiaoying Zhang, Lan Xu, Chaorong Ge, Ni An, Gaoyue Jiang, Jialing Xie, Han Zhang, Jiayi Jiang, Xiaotian Li, Lei Yao, Suping Zhang, Daohong Zhou, Jianrong Wang
Autophagy protects hematopoietic cells from radiation damage in part by promoting DNA damage repair. However, the molecular mechanisms by which autophagy regulates DNA damage repair remain largely elusive. Here, we report that this radioprotective effect of autophagy depends on STAT3 signaling in murine bone marrow mononuclear cells (BM-MNCs). Specifically, we found that STAT3 activation and nuclear translocation in BM-MNCs were increased by activation of autophagy with an mTOR inhibitor and decreased by knockout of the autophagy gene Atg7...
March 2017: Radiation Research
Xiaofan Li, Eric M Burton, Sumita Bhaduri-McIntosh
Trials to reintroduce chloroquine into regions of Africa where P. falciparum has regained susceptibility to chloroquine are underway. However, there are long-standing concerns about whether chloroquine increases lytic-replication of Epstein-Barr virus (EBV), thereby contributing to the development of endemic Burkitt lymphoma. We report that chloroquine indeed drives EBV replication by linking the DNA repair machinery to chromatin remodeling-mediated transcriptional repression. Specifically, chloroquine utilizes ataxia telangiectasia mutated (ATM) to phosphorylate the universal transcriptional corepressor Krüppel-associated Box-associated protein 1/tripartite motif-containing protein 28 (KAP1/TRIM28) at serine 824 -a mechanism that typically facilitates repair of double-strand breaks in heterochromatin, to instead activate EBV...
March 2017: PLoS Pathogens
Eva Bártová, Barbora Malyšková, Denisa Komůrková, Soňa Legartová, Jana Suchánková, Jana Krejčí, Stanislav Kozubek
This review focuses on the function of heterochromatin protein HP1 in response to DNA damage. We specifically outline the regulatory mechanisms in which HP1 and its interacting partners are involved. HP1 protein subtypes (HP1α, HP1β, and HP1γ) are the main components of constitutive heterochromatin, and HP1α and HP1β in particular are responsible for heterochromatin maintenance. The recruitment of these proteins to DNA lesions is also important from the perspective of proper DNA repair mechanisms. For example, HP1α is necessary for the binding of the main DNA damage-related protein 53BP1 at DNA repair foci, which are positive not only for the HP1α protein but also for the RAD51 protein, a component of DNA repair machinery...
May 2017: Protoplasma
Y Jiang, H-C Chen, X Su, P A Thompson, X Liu, K-A Do, W Wierda, M J Keating, W Plunkett
Approximately 10-20% of chronic lymphocytic leukemia (CLL) patients exhibit del(11q22-23) before treatment, this cohort increases to over 40% upon progression following chemoimmunotherapy. The coding sequence of the DNA damage response gene, ataxia-telangiectasia-mutated (ATM), is contained in this deletion. The residual ATM allele is frequently mutated, suggesting a relationship between gene function and clinical response. To investigate this possibility, we sought to develop and validate an assay for the function of ATM protein in these patients...
September 2, 2016: Blood Cancer Journal
Masayoshi Ikeuchi, Yasunori Fukumoto, Takuya Honda, Takahisa Kuga, Youhei Saito, Naoto Yamaguchi, Yuji Nakayama
An increase in Src activity is commonly observed in epithelial cancers. Aberrant activation of the kinase activity is associated with malignant progression. However, the mechanisms that underlie the Src-induced malignant progression of cancer are not completely understood. We show here that v-Src, an oncogene that was first identified from a Rous sarcoma virus and a mutant variant of c-Src, leads to an increase in the number of anaphase and telophase cells having chromosome bridges. v-Src increases the number of γH2AX foci, and this increase is inhibited by treatment with PP2, a Src kinase inhibitor...
June 2, 2016: International Journal of Molecular Sciences
Yvonne Lorat, Stefanie Schanz, Claudia E Rübe
PURPOSE: Intensity-modulated radiotherapy (IMRT) enables the delivery of high doses to target volume while sparing surrounding nontargeted tissues. IMRT treatment, however, substantially increases the normal tissue volume receiving low-dose irradiation, but the biologic consequences are unclear. EXPERIMENTAL DESIGN: Using mouse strains that varied in genetic DNA repair capacity, we investigated the DNA damage response of cortical neurons during daily low-dose irradiation (0...
November 1, 2016: Clinical Cancer Research: An Official Journal of the American Association for Cancer Research
Bryndon J Oleson, Katarzyna A Broniowska, Aaron Naatz, Neil Hogg, Vera L Tarakanova, John A Corbett
Nitric oxide, produced in pancreatic β cells in response to proinflammatory cytokines, plays a dual role in the regulation of β-cell fate. While nitric oxide induces cellular damage and impairs β-cell function, it also promotes β-cell survival through activation of protective pathways that promote β-cell recovery. In this study, we identify a novel mechanism in which nitric oxide prevents β-cell apoptosis by attenuating the DNA damage response (DDR). Nitric oxide suppresses activation of the DDR (as measured by γH2AX formation and the phosphorylation of KAP1 and p53) in response to multiple genotoxic agents, including camptothecin, H2O2, and nitric oxide itself, despite the presence of DNA damage...
August 1, 2016: Molecular and Cellular Biology
Ching-Ying Kuo, Xu Li, Jeremy M Stark, Hsiu-Ming Shih, David K Ann
Both RNF4 and KAP1 play critical roles in the response to DNA double-strand breaks (DSBs), but the functional interplay of RNF4 and KAP1 in regulating DNA damage response remains unclear. We have previously demonstrated the recruitment and degradation of KAP1 by RNF4 require the phosphorylation of Ser824 (pS824) and SUMOylation of KAP1. In this report, we show the retention of DSB-induced pS824-KAP1 foci and RNF4 abundance are inversely correlated as cell cycle progresses. Following irradiation, pS824-KAP1 foci predominantly appear in the cyclin A (-) cells, whereas RNF4 level is suppressed in the G0-/G1-phases and then accumulates during S-/G2-phases...
2016: Cell Cycle
Shiv K Gupta, Sani H Kizilbash, Brett L Carlson, Ann C Mladek, Felix Boakye-Agyeman, Katrina K Bakken, Jenny L Pokorny, Mark A Schroeder, Paul A Decker, Ling Cen, Jeanette E Eckel-Passow, Gobinda Sarkar, Karla V Ballman, Joel M Reid, Robert B Jenkins, Roeland G Verhaak, Erik P Sulman, Gaspar J Kitange, Jann N Sarkaria
BACKGROUND: Sensitizing effects of poly-ADP-ribose polymerase inhibitors have been studied in several preclinical models, but a clear understanding of predictive biomarkers is lacking. In this study, in vivo efficacy of veliparib combined with temozolomide (TMZ) was evaluated in a large panel of glioblastoma multiforme (GBM) patient-derived xenografts (PDX) and potential biomarkers were analyzed. METHODS: The efficacy of TMZ alone vs TMZ/veliparib was compared in a panel of 28 GBM PDX lines grown as orthotopic xenografts (8-10 mice per group); all tests of statistical significance were two-sided...
May 2016: Journal of the National Cancer Institute
Carolin Bürck, Andreas Mund, Julia Berscheminski, Lisa Kieweg, Sarah Müncheberg, Thomas Dobner, Sabrina Schreiner
UNLABELLED: Once transported to the replication sites, human adenoviruses (HAdVs) need to ensure decondensation and transcriptional activation of their viral genomes to synthesize viral proteins and initiate steps to reprogram the host cell for viral replication. These early stages during adenoviral infection are poorly characterized but represent a decisive moment in the establishment of a productive infection. Here, we identify a novel host viral restriction factor, KAP1. This heterochromatin-associated transcription factor regulates the dynamic organization of the host chromatin structure via its ability to influence epigenetic marks and chromatin compaction...
January 15, 2016: Journal of Virology
Martina Magni, Vincenzo Ruscica, Michela Restelli, Enrico Fontanella, Giacomo Buscemi, Laura Zannini
Cell cycle and apoptosis regulator 2 (CCAR2, formerly known as DBC1) is a nuclear protein largely involved in DNA damage response, apoptosis, metabolism, chromatin structure and transcription regulation. Upon DNA lesions, CCAR2 is phosphorylated by the apical kinases ATM/ATR and this phosphorylation enhances CCAR2 binding to SIRT1, leading to SIRT1 inhibition, p53 acetylation and p53-dependent apoptosis. Recently, we found that also the checkpoint kinase Chk2 and the proteasome activator REGγ are required for efficient CCAR2-mediated inhibition of SIRT1 and induction of p53-dependent apoptosis...
July 10, 2015: Oncotarget
J Kim, Y Liu, M Qiu, Y Xu
The pluripotency gene Nanog is not expressed in normal adult tissues but is overexpressed in some human cancers. However, the tumorigenic roles of Nanog remain unclear. The ectopic expression of Nanog is not sufficient to induce spontaneous tumors in mice but can promote metastasis of established tumors by activating the expression of metastatic genes. The expression of Nanog in mouse skin activates tumor suppressor p53, leading to the differentiation of epidermal stem cells. In the absence of p53, Nanog induces spontaneous squamous cell carcinoma, identifying a novel role of Nanog in tumorigenesis...
March 10, 2016: Oncogene
Michal W Luczak, Samantha E Green, Anatoly Zhitkovich
BACKGROUND: Carcinogenic hexavalent chromium [Cr(VI)] requires cellular reduction to generate DNA damage. Metabolism of Cr(VI) by its principal reducer ascorbate (Asc) lacks a Cr(V) intermediate, which is abundant in reactions with a minor reducing agent, glutathione. Cultured cells are widely used in mechanistic studies of Cr(VI) toxicity; however, they typically contain < 1% of normal Asc levels. Asc deficiency is also expected to diminish protection against reactive oxygen species...
January 2016: Environmental Health Perspectives
Yi-Hui Lin, Jian Yuan, Huadong Pei, Tongzheng Liu, David K Ann, Zhenkun Lou
Homologous recombination and non-homologous end joining are two major DNA double-strand-break repair pathways. While HR-mediated repair requires a homologous sequence as the guiding template to restore the damage site precisely, NHEJ-mediated repair ligates the DNA lesion directly and increases the risk of losing nucleotides. Therefore, how a cell regulates the balance between HR and NHEJ has become an important issue for maintaining genomic integrity over time. Here we report that SIRT1-dependent KAP1 deacetylation positively regulates NHEJ...
2015: PloS One
Alkmini Kalousi, Anne-Sophie Hoffbeck, Platonas N Selemenakis, Jordan Pinder, Kienan I Savage, Kum Kum Khanna, Laurent Brino, Graham Dellaire, Vassilis G Gorgoulis, Evi Soutoglou
Cells experience damage from exogenous and endogenous sources that endanger genome stability. Several cellular pathways have evolved to detect DNA damage and mediate its repair. Although many proteins have been implicated in these processes, only recent studies have revealed how they operate in the context of high-ordered chromatin structure. Here, we identify the nuclear oncogene SET (I2PP2A) as a modulator of DNA damage response (DDR) and repair in chromatin surrounding double-strand breaks (DSBs). We demonstrate that depletion of SET increases DDR and survival in the presence of radiomimetic drugs, while overexpression of SET impairs DDR and homologous recombination (HR)-mediated DNA repair...
April 7, 2015: Cell Reports
Mariko Morii, Yasunori Fukumoto, Sho Kubota, Noritaka Yamaguchi, Yuji Nakayama, Naoto Yamaguchi
The DNA damage checkpoint arrests cell cycle progression to allow time for DNA repair. After completion of DNA repair, checkpoint activation is terminated, and cell cycle progression is resumed in a process called checkpoint recovery. The activation of the checkpoint has been studied in depth, but little is known about recovery from the DNA damage checkpoint. Recently we showed that Src family kinases promote recovery from the G2 DNA damage checkpoint. Here we show that imatinib inhibits inactivation of ATM/ATR signaling pathway to suppress recovery from Adriamycin/doxorubicin-induced DNA damage checkpoint arrest...
August 2015: Cell Biology International
Joseph B Addison, Colton Koontz, James H Fugett, Chad J Creighton, Dongquan Chen, Mark K Farrugia, Renata R Padon, Maria A Voronkova, Sarah L McLaughlin, Ryan H Livengood, Chen-Chung Lin, J Michael Ruppert, Elena N Pugacheva, Alexey V Ivanov
KAP1 (TRIM28) is a transcriptional regulator in embryonic development that controls stem cell self-renewal, chromatin organization, and the DNA damage response, acting as an essential corepressor for KRAB family zinc finger proteins (KRAB-ZNF). To gain insight into the function of this large gene family, we developed an antibody that recognizes the conserved zinc fingers linker region (ZnFL) in multiple KRAB-ZNF. Here, we report that the expression of many KRAB-ZNF along with active SUMOlyated KAP1 is elevated widely in human breast cancers...
January 15, 2015: Cancer Research
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"