Dimerization of MORC2 through its C-terminal coiled-coil domain enhances chromatin dynamics and promotes DNA repair

AbstractDecondesation of the highly compacted chromatin architecture is essential for efficient DNA repair, but how this is achieved remains largely unknown. Here, we report that microrchidia family CW-type zinc finger protein 2 (MORC2), a newly identified ATPase-dependent chromatin remodeling enzyme, is required for nucleosome destabilization after DNA damage through loosening the histone-DNA interaction. Depletion of MORC2 attenuates phosphorylated histone H2AX (γH2AX) focal formation, compromises the recruitment of DNA repair proteins, BRCA1, 53BP1, and Rad51, to sites of DNA damage, and consequently reduces cell survival following treatment with DNA-damaging chemotherapeutic drug camptothecin (CPT). Furthermore, we demonstrate that MORC2 can form a homodimer through its C-terminal coiled-coil (CC) domain, a process that is enhanced in response to CPT-induced DNA damage. Deletion of the C-terminal CC domain in MORC2 disrupts its homodimer formation and impairs its ability to destabilize histone-DNA interaction after DNA damage. Consistently, expression of dimerization-defective MORC2 mutant results in impaired the recruitment of DNA repair proteins to damaged chromatin and decreased cell survival after CPT treatment. Together, these findings uncover a new mechanism for MORC2 in modulating chromatin dynamics and DDR signaling through its c-terminal dimerization.

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Multifunctional Involvement of a C2H2 Zinc Finger Protein (PbZfp) in Malaria Transmission, Histone Modification, and Susceptibility to DNA Damage Response

mBio ◽

10.1128/mbio.01298-17 ◽

2017 ◽

Vol 8 (4) ◽

Cited By ~ 2

Author(s):

Anusha M. Gopalakrishnan ◽

Ahmed S. I. Aly ◽

L. Aravind ◽

Nirbhay Kumar

Keyword(s):

Dna Damage ◽

Dna Repair ◽

Homologous Recombination ◽

Zinc Finger ◽

Plasmodium Berghei ◽

Zinc Finger Protein ◽

Genetic Recombination ◽

Mosquito Vector ◽

Histone 3 ◽

Finger Protein

ABSTRACT In sexually reproducing organisms, meiosis is an essential step responsible for generation of haploid gametes from diploid somatic cells. The quest for understanding regulatory mechanisms of meiotic recombination in Plasmodium led to identification of a gene encoding a protein that contains 11 copies of C 2 H 2 zinc fingers (ZnF). Reverse genetic approaches were used to create Plasmodium berghei parasites either lacking expression of full-length Plasmodium berghei zinc finger protein (PbZfp) (knockout [KO]) or expressing PbZfp lacking C-terminal zinc finger region (truncated [Trunc]). Mice infected with KO parasites survived two times longer ( P < 0.0001) than mice infected with wild-type (WT) parasites. In mosquito transmission experiments, the infectivity of KO and Trunc parasites was severely compromised (>95% oocyst reduction). KO parasites revealed a total lack of trimethylation of histone 3 at several lysine residues (K4, K27, and K36) without any effect on acetylation patterns (H3K9, H3K14, and H4K16). Reduced DNA damage and reduced expression of topoisomerase-like Spo11 in the KO parasites with normal Rad51 expression further suggest a functional role for PbZfp during genetic recombination that involves DNA double-strand break (DSB) formation followed by DNA repair. These finding raise the possibility of some convergent similarities of PbZfp functions to functions of mammalian PRDM9, also a C 2 H 2 ZnF protein with histone 3 lysine 4 (H3K4) methyltransferase activity. These functions include the major role played by the latter in binding recombination hotspots in the genome during meiosis and trimethylation of the associated histones and subsequent chromatin recruitment of topoisomerase-like Spo11 to catalyze DNA DSB formation and DMC1/Rad51-mediated DNA repair and homologous recombination. IMPORTANCE Malaria parasites are haploid throughout their life cycle except for a brief time period when zygotes are produced as a result of fertilization between male and female gametes during transmission through the mosquito vector. The reciprocal recombination events that follow zygote formation ensure orderly segregation of homologous chromosomes during meiosis, creating genetic diversity among offspring. Studies presented in the current manuscript identify a novel C2H2 ZnF-containing protein exhibiting multifunctional roles in parasite virulence, mosquito transmission, and homologous recombination during meiosis. Understanding the transmission biology of malaria will result in the identification of novel targets for transmission-blocking intervention approaches.

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DNA Damage-Dependent Acetylation and Ubiquitination of H2AX Enhances Chromatin Dynamics

Molecular and Cellular Biology ◽

10.1128/mcb.00579-07 ◽

2007 ◽

Vol 27 (20) ◽

pp. 7028-7040 ◽

Cited By ~ 251

Author(s):

Tsuyoshi Ikura ◽

Satoshi Tashiro ◽

Akemi Kakino ◽

Hiroki Shima ◽

Naduparambil Jacob ◽

...

Keyword(s):

Dna Damage ◽

Dna Repair ◽

Cell Cycle Checkpoints ◽

Variant Form ◽

Ionizing Irradiation ◽

Chromatin Dynamics ◽

Histone H2ax ◽

Damage Response ◽

Ubiquitin Conjugating Enzyme ◽

Chromatin Reorganization

ABSTRACT Chromatin reorganization plays an important role in DNA repair, apoptosis, and cell cycle checkpoints. Among proteins involved in chromatin reorganization, TIP60 histone acetyltransferase has been shown to play a role in DNA repair and apoptosis. However, how TIP60 regulates chromatin reorganization in the response of human cells to DNA damage is largely unknown. Here, we show that ionizing irradiation induces TIP60 acetylation of histone H2AX, a variant form of H2A known to be phosphorylated following DNA damage. Furthermore, TIP60 regulates the ubiquitination of H2AX via the ubiquitin-conjugating enzyme UBC13, which is induced by DNA damage. This ubiquitination of H2AX requires its prior acetylation. We also demonstrate that acetylation-dependent ubiquitination by the TIP60-UBC13 complex leads to the release of H2AX from damaged chromatin. We conclude that the sequential acetylation and ubiquitination of H2AX by TIP60-UBC13 promote enhanced histone dynamics, which in turn stimulate a DNA damage response.

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Host DNA Repair Proteins in Response toPseudomonas aeruginosain Lung Epithelial Cells and in Mice

Infection and Immunity ◽

10.1128/iai.00815-10 ◽

2010 ◽

Vol 79 (1) ◽

pp. 75-87 ◽

Cited By ~ 35

Author(s):

Min Wu ◽

Huang Huang ◽

Weidong Zhang ◽

Shibichakravarthy Kannan ◽

Andrew Weaver ◽

...

Keyword(s):

Dna Damage ◽

Dna Repair ◽

Epithelial Cells ◽

Critical Role ◽

Lung Epithelial Cells ◽

Host Cells ◽

Myeloperoxidase Activity ◽

Gram Negative ◽

Lung Epithelial ◽

Dna Repair Proteins

ABSTRACTAlthough DNA repair proteins in bacteria are critical for pathogens' genome stability and for subverting the host defense, the role of host DNA repair proteins in response to bacterial infection is poorly defined. Here, we demonstrate, for the first time, that infection with the Gram-negative bacteriumPseudomonas aeruginosasignificantly altered the expression and enzymatic activity of 8-oxoguanine DNA glycosylase (OGG1) in lung epithelial cells. Downregulation of OGG1 by a small interfering RNA strategy resulted in severe DNA damage and cell death. In addition, acetylation of OGG1 is required for host responses to bacterial genotoxicity, as mutations of OGG1 acetylation sites increased Cockayne syndrome group B (CSB) protein expression. These results also indicate that CSB may be involved in DNA repair activity during infection. Furthermore, OGG1 knockout mice exhibited increased lung injury after infection withP. aeruginosa, as demonstrated by higher myeloperoxidase activity and lipid peroxidation. Together, our studies indicate thatP. aeruginosainfection induces significant DNA damage in host cells and that DNA repair proteins play a critical role in the host response toP. aeruginosainfection, serving as promising targets for the treatment of this condition and perhaps more broadly Gram-negative bacterial infections.

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Ultraviolet Light-Induced and Spontaneous Recombination in Eukaryotes Roles of DNA Damage and DNA Repair Proteins

DNA Damage and Repair ◽

10.1385/1-59259-095-0:329 ◽

2003 ◽

pp. 329-357

Author(s):

Colin A. Bill ◽

Jac A. Nickoloff

Keyword(s):

Dna Damage ◽

Dna Repair ◽

Ultraviolet Light ◽

Spontaneous Recombination ◽

Dna Repair Proteins

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RNF168-mediated localization of BARD1 recruits the BRCA1-PALB2 complex to DNA damage

Nature Communications ◽

10.1038/s41467-021-25346-4 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

John J. Krais ◽

Yifan Wang ◽

Pooja Patel ◽

Jayati Basu ◽

Andrea J. Bernhardy ◽

...

Keyword(s):

Dna Damage ◽

Ubiquitin Ligase ◽

E3 Ubiquitin Ligase ◽

Coiled Coil ◽

Histone H2a ◽

Dna Breaks ◽

Diverse Range ◽

Dna Damage Signaling ◽

Dna Repair Proteins ◽

K 13

AbstractDNA damage prompts a diverse range of alterations to the chromatin landscape. The RNF168 E3 ubiquitin ligase catalyzes the mono-ubiquitination of histone H2A at lysine (K)13/15 (mUb-H2A), forming a binding module for DNA repair proteins. BRCA1 promotes homologous recombination (HR), in part, through its interaction with PALB2, and the formation of a larger BRCA1-PALB2-BRCA2-RAD51 (BRCA1-P) complex. The mechanism by which BRCA1-P is recruited to chromatin surrounding DNA breaks is unclear. In this study, we reveal that an RNF168-governed signaling pathway is responsible for localizing the BRCA1-P complex to DNA damage. Using mice harboring a Brca1CC (coiled coil) mutation that blocks the Brca1-Palb2 interaction, we uncovered an epistatic relationship between Rnf168− and Brca1CC alleles, which disrupted development, and reduced the efficiency of Palb2-Rad51 localization. Mechanistically, we show that RNF168-generated mUb-H2A recruits BARD1 through a BRCT domain ubiquitin-dependent recruitment motif (BUDR). Subsequently, BARD1-BRCA1 accumulate PALB2-RAD51 at DNA breaks via the CC domain-mediated BRCA1-PALB2 interaction. Together, these findings establish a series of molecular interactions that connect the DNA damage signaling and HR repair machinery.

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DNA repair mechanisms and gametogenesis

Reproduction ◽

10.1530/rep.0.1210031 ◽

2001 ◽

pp. 31-39 ◽

Cited By ~ 105

Author(s):

WM Baarends ◽

R van der Laan ◽

JA Grootegoed

Keyword(s):

Dna Damage ◽

Dna Repair ◽

Gene Knockout ◽

Cell Cycle Checkpoint ◽

Checkpoint Control ◽

Chromatin Dynamics ◽

Dna Mismatch ◽

Dna Repair Mechanisms ◽

Genes Encoding ◽

Repair Mechanisms

In mammals, there is a complex and intriguing relationship between DNA repair and gametogenesis. DNA repair mechanisms are involved not only in the repair of different types of DNA damage in developing germline cells, but also take part in the meiotic recombination process. Furthermore, the DNA repair mechanisms should tolerate mutations occurring during gametogenesis, to a limited extent. In the present review, several gametogenic aspects of DNA mismatch repair, homologous recombination repair and postreplication repair are discussed. In addition, the role of DNA damage-induced cell cycle checkpoint control is considered briefly. It appears that many genes encoding proteins that take part in DNA repair mechanisms show enhanced or specialized expression during mammalian gametogenesis, and several gene knockout mouse models show male or female infertility. On the basis of such knowledge and models, future experiments may provide more information about the precise relationship between DNA repair, chromatin dynamics, and genomic stability versus instability during gametogenesis.

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Abstract 4286: Essential Roles of Jab1 in Cell Survival, Spontaneous DNA Damage, and DNA Repair

10.1158/1538-7445.am2011-4286 ◽

2011 ◽

Author(s):

Francois Claret

Keyword(s):

Dna Damage ◽

Dna Repair ◽

Cell Survival

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Acquired temozolomide resistance in MGMT-deficient glioblastoma cells is associated with regulation of DNA repair by DHC2

Brain ◽

10.1093/brain/awz202 ◽

2019 ◽

Vol 142 (8) ◽

pp. 2352-2366 ◽

Cited By ~ 15

Author(s):

Guo-zhong Yi ◽

Guanglong Huang ◽

Manlan Guo ◽

Xi’an Zhang ◽

Hai Wang ◽

...

Keyword(s):

Dna Damage ◽

Dna Repair ◽

Dna Methyltransferase ◽

Molecular Mechanisms ◽

Progression Free Survival ◽

Recurrent Glioblastoma ◽

Dna Lesions ◽

Dna Repair Proteins

Abstract The acquisition of temozolomide resistance is a major clinical challenge for glioblastoma treatment. Chemoresistance in glioblastoma is largely attributed to repair of temozolomide-induced DNA lesions by O6-methylguanine-DNA methyltransferase (MGMT). However, some MGMT-deficient glioblastomas are still resistant to temozolomide, and the underlying molecular mechanisms remain unclear. We found that DYNC2H1 (DHC2) was expressed more in MGMT-deficient recurrent glioblastoma specimens and its expression strongly correlated to poor progression-free survival in MGMT promotor methylated glioblastoma patients. Furthermore, silencing DHC2, both in vitro and in vivo, enhanced temozolomide-induced DNA damage and significantly improved the efficiency of temozolomide treatment in MGMT-deficient glioblastoma. Using a combination of subcellular proteomics and in vitro analyses, we showed that DHC2 was involved in nuclear localization of the DNA repair proteins, namely XPC and CBX5, and knockdown of either XPC or CBX5 resulted in increased temozolomide-induced DNA damage. In summary, we identified the nuclear transportation of DNA repair proteins by DHC2 as a critical regulator of acquired temozolomide resistance in MGMT-deficient glioblastoma. Our study offers novel insights for improving therapeutic management of MGMT-deficient glioblastoma.

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