Role of homologous recombination genesRAD51,RAD52, andRAD59in the repair of lesions caused by γ-radiation to cycling and G2/M-arrested cells ofCandida albicans

2018 ◽  
Vol 20 (12) ◽  
pp. e12950 ◽  
Author(s):  
Alberto Bellido ◽  
Belén Hermosa ◽  
Toni Ciudad ◽  
Germán Larriba
Cancers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2547
Author(s):  
Keunsoo Kang ◽  
Yoonjung Choi ◽  
Hyeonjin Moon ◽  
Chaelin You ◽  
Minjin Seo ◽  
...  

RAD51 is a recombinase that plays a pivotal role in homologous recombination. Although the role of RAD51 in homologous recombination has been extensively studied, it is unclear whether RAD51 can be involved in gene regulation as a co-factor. In this study, we found evidence that RAD51 may contribute to the regulation of genes involved in the autophagy pathway with E-box proteins such as USF1, USF2, and/or MITF in GM12878, HepG2, K562, and MCF-7 cell lines. The canonical USF binding motif (CACGTG) was significantly identified at RAD51-bound cis-regulatory elements in all four cell lines. In addition, genome-wide USF1, USF2, and/or MITF-binding regions significantly coincided with the RAD51-associated cis-regulatory elements in the same cell line. Interestingly, the promoters of genes associated with the autophagy pathway, such as ATG3 and ATG5, were significantly occupied by RAD51 and regulated by RAD51 in HepG2 and MCF-7 cell lines. Taken together, these results unveiled a novel role of RAD51 and provided evidence that RAD51-associated cis-regulatory elements could possibly be involved in regulating autophagy-related genes with E-box binding proteins.


2019 ◽  
Vol 105 (3) ◽  
pp. 839-853
Author(s):  
Aglaia Kyrilli ◽  
David Gacquer ◽  
Vincent Detours ◽  
Anne Lefort ◽  
Frédéric Libert ◽  
...  

Abstract Background The early molecular events in human thyrocytes after 131I exposure have not yet been unravelled. Therefore, we investigated the role of TSH in the 131I-induced DNA damage response and gene expression in primary cultured human thyrocytes. Methods Following exposure of thyrocytes, in the presence or absence of TSH, to 131I (β radiation), γ radiation (3 Gy), and hydrogen peroxide (H2O2), we assessed DNA damage, proliferation, and cell-cycle status. We conducted RNA sequencing to profile gene expression after each type of exposure and evaluated the influence of TSH on each transcriptomic response. Results Overall, the thyrocyte responses following exposure to β or γ radiation and to H2O2 were similar. However, TSH increased 131I-induced DNA damage, an effect partially diminished after iodide uptake inhibition. Specifically, TSH increased the number of DNA double-strand breaks in nonexposed thyrocytes and thus predisposed them to greater damage following 131I exposure. This effect most likely occurred via Gα q cascade and a rise in intracellular reactive oxygen species (ROS) levels. β and γ radiation prolonged thyroid cell-cycle arrest to a similar extent without sign of apoptosis. The gene expression profiles of thyrocytes exposed to β/γ radiation or H2O2 were overlapping. Modulations in genes involved in inflammatory response, apoptosis, and proliferation were observed. TSH increased the number and intensity of modulation of differentially expressed genes after 131I exposure. Conclusions TSH specifically increased 131I-induced DNA damage probably via a rise in ROS levels and produced a more prominent transcriptomic response after exposure to 131I.


2018 ◽  
Vol 8 (10) ◽  
Author(s):  
Subodh Kumar ◽  
Srikanth Talluri ◽  
Jagannath Pal ◽  
Xiaoli Yuan ◽  
Renquan Lu ◽  
...  

PLoS Genetics ◽  
2021 ◽  
Vol 17 (5) ◽  
pp. e1008919
Author(s):  
Miguel Hernandez Sanchez-Rebato ◽  
Alida M. Bouatta ◽  
Maria E. Gallego ◽  
Charles I. White ◽  
Olivier Da Ines

An essential component of the homologous recombination machinery in eukaryotes, the RAD54 protein is a member of the SWI2/SNF2 family of helicases with dsDNA-dependent ATPase, DNA translocase, DNA supercoiling and chromatin remodelling activities. It is a motor protein that translocates along dsDNA and performs multiple functions in homologous recombination. In particular, RAD54 is an essential cofactor for regulating RAD51 activity. It stabilizes the RAD51 nucleofilament, remodels nucleosomes, and stimulates homology search and strand invasion activity of RAD51. Accordingly, deletion of RAD54 has dramatic consequences on DNA damage repair in mitotic cells. In contrast, its role in meiotic recombination is less clear. RAD54 is essential for meiotic recombination in Drosophila and C. elegans, but plays minor roles in yeast and mammals. We present here characterization of the roles of RAD54 in meiotic recombination in the model plant Arabidopsis thaliana. Absence of RAD54 has no detectable effect on meiotic recombination in otherwise wild-type plants but RAD54 becomes essential for meiotic DSB repair in absence of DMC1. In Arabidopsis, dmc1 mutants have an achiasmate meiosis, in which RAD51 repairs meiotic DSBs. Lack of RAD54 leads to meiotic chromosomal fragmentation in absence of DMC1. The action of RAD54 in meiotic RAD51 activity is thus mainly downstream of the role of RAD51 in supporting the activity of DMC1. Equivalent analyses show no effect on meiosis of combining dmc1 with the mutants of the RAD51-mediators RAD51B, RAD51D and XRCC2. RAD54 is thus required for repair of meiotic DSBs by RAD51 and the absence of meiotic phenotype in rad54 plants is a consequence of RAD51 playing a RAD54-independent supporting role to DMC1 in meiotic recombination.


2019 ◽  
Vol 47 (17) ◽  
pp. 9160-9179 ◽  
Author(s):  
Soon Young Hwang ◽  
Mi Ae Kang ◽  
Chul Joon Baik ◽  
Yejin Lee ◽  
Ngo Thanh Hang ◽  
...  

Abstract The pleiotropic CCCTC-binding factor (CTCF) plays a role in homologous recombination (HR) repair of DNA double-strand breaks (DSBs). However, the precise mechanistic role of CTCF in HR remains largely unclear. Here, we show that CTCF engages in DNA end resection, which is the initial, crucial step in HR, through its interactions with MRE11 and CtIP. Depletion of CTCF profoundly impairs HR and attenuates CtIP recruitment at DSBs. CTCF physically interacts with MRE11 and CtIP and promotes CtIP recruitment to sites of DNA damage. Subsequently, CTCF facilitates DNA end resection to allow HR, in conjunction with MRE11–CtIP. Notably, the zinc finger domain of CTCF binds to both MRE11 and CtIP and enables proficient CtIP recruitment, DNA end resection and HR. The N-terminus of CTCF is able to bind to only MRE11 and its C-terminus is incapable of binding to MRE11 and CtIP, thereby resulting in compromised CtIP recruitment, DSB resection and HR. Overall, this suggests an important function of CTCF in DNA end resection through the recruitment of CtIP at DSBs. Collectively, our findings identify a critical role of CTCF at the first control point in selecting the HR repair pathway.


2020 ◽  
Vol 118 (3) ◽  
pp. 73a
Author(s):  
Zane Lombardo ◽  
Sudipta Lahiri ◽  
Bharat Lakhani ◽  
Manju M. Hingorani ◽  
David L. Beveridge ◽  
...  

2020 ◽  
Vol 98 (3) ◽  
pp. 314-326 ◽  
Author(s):  
Kathleen M. Attwood ◽  
Jayme Salsman ◽  
Dudley Chung ◽  
Sabateeshan Mathavarajah ◽  
Carter Van Iderstine ◽  
...  

Promyelocytic leukemia nuclear bodies (PML NBs) are nuclear subdomains that respond to genotoxic stress by increasing in number via changes in chromatin structure. However, the role of the PML protein and PML NBs in specific mechanisms of DNA repair has not been fully characterized. Here, we have directly examined the role of PML in homologous recombination (HR) using I-SceI extrachromosomal and chromosome-based homology-directed repair (HDR) assays, and in HDR by CRISPR/Cas9-mediated gene editing. We determined that PML loss can inhibit HR in an extrachromosomal HDR assay but had less of an effect on CRISPR/Cas9-mediated chromosomal HDR. Overexpression of PML also inhibited both CRISPR HDR and I-SceI-induced HDR using a chromosomal reporter, and in an isoform-specific manner. However, the impact of PML overexpression on the chromosomal HDR reporter was dependent on the intranuclear chromosomal positioning of the reporter. Specifically, HDR at the TAP1 gene locus, which is associated with PML NBs, was reduced compared with a locus not associated with a PML NB; yet, HDR could be reduced at the non-PML NB-associated locus by PML overexpression. Thus, both loss and overexpression of PML isoforms can inhibit HDR, and proximity of a chromosomal break to a PML NB can impact HDR efficiency.


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