Regulation of Ku gene promoters in Arabidopsis by hormones and stress

2008 ◽  
Vol 35 (4) ◽  
pp. 265 ◽  
Author(s):  
Wen-Chi Chang ◽  
Yung-Kai Wang ◽  
Pei-Feng Liu ◽  
Yu-Fang Tsai ◽  
Lih-Ren Kong ◽  
...  
Keyword(s):  
Higher Plants ◽  
Telomere Maintenance ◽  
Gene Promoters ◽  
Start Site ◽  
End Joining ◽  
Transcription Start ◽  
Cellular Processes ◽  
Gus Reporter ◽  
Non Homologous End Joining ◽  
Ku Gene

The Ku70/Ku80 heterodimer plays a crucial role in non-homologous end-joining during DNA repair, and is also involved in multiple cellular processes such as telomere maintenance, transcription, and apoptosis. In this study, we investigate the regulation of AtKu genes in higher plants. Promoters of the AtKu70 and AtKu80 were isolated from Arabidopsis and their activities characterised using GUS reporter constructs. AtKu promoter activities were relatively higher in hypocotyls and cotyledons upon germination and in stigma and siliques as well at their early developing stages. Furthermore, AtKu promoter activities could be enhanced by gibberellic acid, auxins, and jasmonic acid, but repressed by abscisic acid, salicylic acid, heat, drought and cold, respectively. Deletion analysis demonstrates minimal lengths of ~400 bp and 600 bp upstream of transcription start site for functional promoters of AtKu70 and AtKu80, respectively. Taken together, expressions of Ku genes are regulated both by developmental programs as well as by plant hormones and environmental stresses.

scholarly journals Gene targeting facilitated by engineered sequence-specific nucleases and its potential for applications in crop improvement

2021 ◽  
Author(s):  
Daisuke Miki ◽  
Rui Wang ◽  
Jing Li ◽  
Dali Kong ◽  
Lei Zhang ◽  
...  
Keyword(s):  
Gene Targeting ◽  
Agronomic Traits ◽  
Higher Plants ◽  
Crop Improvement ◽  
Strand Break ◽  
End Joining ◽  
Homology Directed Repair ◽  
Target Dna ◽  
Targeted Gene Editing ◽  
Non Homologous End Joining

Abstract Humans are currently facing the problem of how to ensure that there is enough food to feed all of the world’s population. Ensuring that the food supply is sufficient will likely require the modification of crop genomes to improve their agronomic traits. The development of engineered sequence-specific nucleases (SSNs) paved the way for targeted gene editing in organisms, including plants. SSNs generate a double-strand break (DSB) at the target DNA site in a sequence-specific manner. These DSBs are predominantly repaired via error-prone non-homologous end joining (NHEJ), and are only rarely repaired via error-free homology-directed repair (HDR) if an appropriate donor template is provided. Gene targeting (GT), i.e., the integration or replacement of a particular sequence, can be achieved with combinations of SSNs and repair donor templates. Although its efficiency is extremely low, GT has been achieved in some higher plants. Here, we provide an overview of SSN-facilitated GT in higher plants and discuss the potential of GT as a powerful tool for generating crop plants with desirable features.

scholarly journals Regulation of Histone Ubiquitination in Response to DNA Double Strand Breaks

Cells ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1699 ◽  
Author(s):  
Lanni Aquila ◽  
Boyko S. Atanassov
Keyword(s):  
Double Strand Breaks ◽  
Deubiquitinating Enzymes ◽  
Dna Double Strand Breaks ◽  
End Joining ◽  
Comprehensive Overview ◽  
Post Translational Modifications ◽  
Strand Breaks ◽  
Cellular Processes ◽  
Downstream Effectors ◽  
Non Homologous End Joining

Eukaryotic cells are constantly exposed to both endogenous and exogenous stressors that promote the induction of DNA damage. Of this damage, double strand breaks (DSBs) are the most lethal and must be efficiently repaired in order to maintain genomic integrity. Repair of DSBs occurs primarily through one of two major pathways: non-homologous end joining (NHEJ) or homologous recombination (HR). The choice between these pathways is in part regulated by histone post-translational modifications (PTMs) including ubiquitination. Ubiquitinated histones not only influence transcription and chromatin architecture at sites neighboring DSBs but serve as critical recruitment platforms for repair machinery as well. The reversal of these modifications by deubiquitinating enzymes (DUBs) is increasingly being recognized in a number of cellular processes including DSB repair. In this context, DUBs ensure proper levels of ubiquitin, regulate recruitment of downstream effectors, dictate repair pathway choice, and facilitate appropriate termination of the repair response. This review outlines the current understanding of histone ubiquitination in response to DSBs, followed by a comprehensive overview of the DUBs that catalyze the removal of these marks.

scholarly journals Functional analysis of the human annexin I and VI gene promoters

1998 ◽  
Vol 332 (3) ◽  
pp. 681-687 ◽  
Author(s):  
Shaun R. DONNELLY ◽  
Stephen E. MOSS
Keyword(s):  
Gene Expression ◽  
Transcription Start Site ◽  
Luciferase Reporter ◽  
Gene Promoters ◽  
Start Site ◽  
Luciferase Reporter Gene ◽  
Transcription Start ◽  
A431 Cells ◽  
Annexin I ◽  
Annexin Vi

To gain insight into the molecular basis of annexin gene expression we have analysed the annexin I and VI gene promoters. A previously described 881 bp sequence immediately upstream of the annexin I transcription start site and a similar size fragment proximal to the annexin VI transcription start site both drove expression of the luciferase reporter gene in fibroblasts and epithelial cells. Neither promoter displayed any sensitivity to dexamethasone, suggesting that the putative glucocorticoid response element in the annexin I promoter is non-functional. Consistent with this, endogenous annexin I gene expression was unaffected by dexamethasone at the mRNA and protein levels in A431 cells. A series of 5´ deletions of the two promoters were examined to define the minimal active sequences. For annexin I this corresponded to a sequence approx. 150 bp upstream of the transcription start site that included CAAT and TATA boxes. Unexpectedly, the annexin VI promoter, which also contains CAAT and TATA boxes, was fully active in the absence of these elements, a 53 bp sequence between these boxes and the transcription start site having maximal activity. Electrophoretic mobility-shift assays with nuclear extracts from A431 and HeLa cells with probes corresponding to this region revealed an SP1-binding site. These results show that the annexin I and VI genes have individual modes of transcriptional regulation and that if either annexin I or annexin VI has an anti-inflammatory role, then this is in the absence of steroid-induced gene expression.

Hyper-Active Non-Homologous End Joining Selects for Synthetic Lethality Resistant and Pathological Hematopoietic Stem Cells

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 5400-5400
Author(s):  
Wei Du ◽  
Surya Amarachintha ◽  
Wilson Andrew ◽  
Qishen Pang
Keyword(s):  
Conflicts Of Interest ◽  
Synthetic Lethality ◽  
Strand Break ◽  
Parp Inhibition ◽  
End Joining ◽  
Dsb Repair ◽  
Hematopoietic Stem ◽  
Cellular Processes ◽  
Stem And Progenitor Cells ◽  
Non Homologous End Joining

Abstract The prominent role of Fanconi anemia (FA) proteins involves homologous recombination (HR) repair. Poly[ADP-ribose] polymerase1 (PARP1) functions in multiple cellular processes including DNA repair and PARP inhibition is an emerging targeted therapy for cancer patients deficient in HR. Here we show that PARP1 activation in hematopoietic stem and progenitor cells (HSPCs) in response to genotoxic or oxidative stress attenuates HSPC exhaustion. Mechanistically, PARP1 controls the balance between HR and non-homologous end joining (NHEJ) in double strand break (DSB) repair by preventing excessive NHEJ. Disruption of the FA core complex skews PARP1 function in DSB repair and led to hyper-active NHEJ in Fanca-/- or Fancc-/- HSPCs. Re-expression of PARP1 rescues the hyper-active NHEJ phenotype in Brca1-/-Parp1-/- but less effective in Fanca-/-Parp1-/- cells. Inhibition of NHEJ prevents myeloid/erythroid pathologies associated with "synthetic lethality" and reduces human engraftment. Our results suggest that hyper-active NHEJ may select for "synthetic lethality" resistant and pathological HSPCs. Disclosures No relevant conflicts of interest to declare.

scholarly journals Microarray screening reveals a non-conventional SUMO-binding mode linked to DNA repair by non-homologous end-joining

2021 ◽  
Author(s):  
Maria Jose Cabello-Lobato ◽  
Matthew Jenner ◽  
Christian M. Loch ◽  
Stephen P. Jackson ◽  
Qian Wu ◽  
...  
Keyword(s):  
Dna Repair ◽  
Binding Mode ◽  
Dna Double Strand Breaks ◽  
End Joining ◽  
Dsb Repair ◽  
Strand Breaks ◽  
Cellular Processes ◽  
Dna Repair Protein ◽  
Microarray Screening ◽  
Non Homologous End Joining

SUMOylation is critical for a plethora of cellular signalling pathways including the repair of DNA double-strand breaks (DSBs). If misrepaired, DSBs can lead to cancer, neurodegeneration, immunodeficiency and premature ageing. Based on systematic proteome microarray screening combined with widely applicable carbene footprinting and high-resolution structural profiling, we define two non-conventional SUMO2-binding modules on XRCC4, a DNA repair protein important for DSB repair by non-homologous end-joining (NHEJ). Mechanistically, interaction of SUMO2 with XRCC4 is incompatible with XRCC4 binding to at least two other NHEJ proteins – XLF and DNA ligase 4 (LIG4). These findings are consistent with SUMO2 interactions of XRCC4 acting as backup pathways at different stages of NHEJ, in the absence of these factors or their dysfunctioning. Such scenarios are not only relevant for carcinogenesis, but also for the design of precision anti-cancer medicines and the optimisation of CRISPR/Cas9-based gene editing. This work reveals insights into topology-specific SUMO recognition and its potential for modulating DSB repair by NHEJ. Moreover, it provides a rich resource on binary SUMO receptors that can be exploited for uncovering regulatory layers in a wide array of cellular processes.

scholarly journals PRMT5 promotes DNA repair through methylation of 53BP1 and is regulated by Src-mediated phosphorylation

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Jee Won Hwang ◽  
Su-Nam Kim ◽  
Nayeon Myung ◽  
Doona Song ◽  
Gyoonhee Han ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Apoptotic Cell ◽  
Negative Regulator ◽  
End Joining ◽  
Cellular Survival ◽  
Cellular Processes ◽  
Nhej Repair ◽  
Damage Process ◽  
Non Homologous End Joining

AbstractPRMT5 participates in various cellular processes, including transcription regulation, signal transduction, mRNA splicing, and DNA repair; however, its mechanism of regulation is poorly understood. Here, we demonstrate that PRMT5 is phosphorylated at residue Y324 by Src kinase, a negative regulator of its activity. Either phosphorylation or substitution of the Y324 residue suppresses PRMT5 activity by preventing its binding with the methyl donor S-adenosyl-L-methionine. Additionally, we show that PRMT5 activity is associated with non-homologous end joining (NHEJ) repair by methylating and stabilizing p53-binding protein 1 (53BP1), which promotes cellular survival after DNA damage. Src-mediated phosphorylation of PRMT5 and the subsequent inhibition of its activity during the DNA damage process blocks NHEJ repair, leading to apoptotic cell death. Altogether, our findings suggest that PRMT5 regulates DNA repair through Src-mediated Y324 phosphorylation in response to DNA damage.

scholarly journals Withanolide D Enhances Radiosensitivity of Human Cancer Cells by Inhibiting DNA Damage Non-homologous End Joining Repair Pathway

2020 ◽  
Vol 9 ◽  
Author(s):  
Jerome Lacombe ◽  
Titouan Cretignier ◽  
Laetitia Meli ◽  
E. M. Kithsiri Wijeratne ◽  
Jean-Luc Veuthey ◽  
...  
Keyword(s):  
Dna Damage ◽  
Cancer Cells ◽  
Human Cancer ◽  
Repair Pathway ◽  
End Joining ◽  
Human Cancer Cells ◽  
Non Homologous End Joining
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