scholarly journals Warsaw breakage syndrome DDX11 helicase acts jointly with RAD17 in the repair of bulky lesions and replication through abasic sites

2018 ◽  
Vol 115 (33) ◽  
pp. 8412-8417 ◽  
Author(s):  
Takuya Abe ◽  
Masato Ooka ◽  
Ryotaro Kawasumi ◽  
Keiji Miyata ◽  
Minoru Takata ◽  
...  
Keyword(s):  
Developmental Disorder ◽  
Genome Instability ◽  
Dna Damage Tolerance ◽  
Checkpoint Activation ◽  
Abasic Sites ◽  
Interstrand Crosslink ◽  
Recombination Repair ◽  
Variable Gene ◽  
Homeologous Recombination ◽  
Dt40 Cells

Warsaw breakage syndrome, a developmental disorder caused by mutations in the DDX11/ChlR1 helicase, shows cellular features of genome instability similar to Fanconi anemia (FA). Here we report that DDX11-deficient avian DT40 cells exhibit interstrand crosslink (ICL)-induced chromatid breakage, with DDX11 functioning as backup for the FA pathway in regard to ICL repair. Importantly, we establish that DDX11 acts jointly with the 9-1-1 checkpoint clamp and its loader, RAD17, primarily in a postreplicative fashion, to promote homologous recombination repair of bulky lesions, but is not required for intra-S checkpoint activation or efficient fork progression. Notably, we find that DDX11 also promotes diversification of the chicken Ig-variable gene, a process triggered by programmed abasic sites, by facilitating both hypermutation and homeologous recombination-mediated gene conversion. Altogether, our results uncover that DDX11 orchestrates jointly with 9-1-1 and its loader, RAD17, DNA damage tolerance at sites of bulky lesions, and endogenous abasic sites. These functions may explain the essential roles of DDX11 and its similarity with 9-1-1 during development.

scholarly journals DNA Damage Tolerance Mechanisms Revealed from the Analysis of Immunoglobulin V Gene Diversification in Avian DT40 Cells

Genes ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 614 ◽  
Author(s):  
Takuya Abe ◽  
Dana Branzei ◽  
Kouji Hirota
Keyword(s):  
Dna Damage ◽  
Dna Replication ◽  
B Lymphocyte ◽  
Damage Tolerance ◽  
Base Pairs ◽  
Dna Damage Tolerance ◽  
Abasic Sites ◽  
Activation Induced Deaminase ◽  
Template Switch ◽  
Dt40 Cells

DNA replication is an essential biochemical reaction in dividing cells that frequently stalls at damaged sites. Homologous/homeologous recombination (HR)-mediated template switch and translesion DNA synthesis (TLS)-mediated bypass processes release arrested DNA replication forks. These mechanisms are pivotal for replication fork maintenance and play critical roles in DNA damage tolerance (DDT) and gap-filling. The avian DT40 B lymphocyte cell line provides an opportunity to examine HR-mediated template switch and TLS triggered by abasic sites by sequencing the constitutively diversifying immunoglobulin light-chain variable gene (IgV). During IgV diversification, activation-induced deaminase (AID) converts dC to dU, which in turn is excised by uracil DNA glycosylase and yields abasic sites within a defined window of around 500 base pairs. These abasic sites can induce gene conversion with a set of homeologous upstream pseudogenes via the HR-mediated template switch, resulting in templated mutagenesis, or can be bypassed directly by TLS, resulting in non-templated somatic hypermutation at dC/dG base pairs. In this review, we discuss recent works unveiling IgV diversification mechanisms in avian DT40 cells, which shed light on DDT mode usage in vertebrate cells and tolerance of abasic sites.

scholarly journals Structural basis of HMCES interactions with DNA reveals multivalent substrate recognition

2019 ◽  
Author(s):  
Levon Halabelian ◽  
Mani Ravichandran ◽  
Yanjun Li ◽  
Hong Zheng ◽  
L. Aravind ◽  
...  
Keyword(s):  
Dna Damage ◽  
Crystal Structures ◽  
Genome Instability ◽  
Substrate Recognition ◽  
Catalytic Triad ◽  
Structural Basis ◽  
Replication Forks ◽  
Abasic Sites ◽  
Stalled Replication Forks ◽  
Gapped Dna

ABSTRACTHMCES can covalently crosslink to abasic sites in single-stranded DNA at stalled replication forks to prevent genome instability. Here, we report crystal structures of the HMCES SRAP domain in complex with DNA-damage substrates, revealing interactions with both single-stranded and duplex segments of 3’ overhang DNA. HMCES may also bind gapped DNA and 5’ overhang structures to align single stranded abasic sites for crosslinking to the conserved Cys2 of its catalytic triad.

scholarly journals Helicase-Like Transcription Factor HLTF and E3 Ubiquitin Ligase SHPRH Confer DNA Damage Tolerance through Direct Interactions with Proliferating Cell Nuclear Antigen (PCNA)

2020 ◽  
Vol 21 (3) ◽  
pp. 693 ◽  
Author(s):  
Mareike Seelinger ◽  
Marit Otterlei
Keyword(s):  
Dna Damage ◽  
Transcription Factor ◽  
Damage Tolerance ◽  
Genome Instability ◽  
Ring Finger ◽  
Nuclear Antigen ◽  
Common Mutation ◽  
Dna Damage Tolerance ◽  
Replicative Stress ◽  
Template Switch

To prevent replication fork collapse and genome instability under replicative stress, DNA damage tolerance (DDT) mechanisms have evolved. The RAD5 homologs, HLTF (helicase-like transcription factor) and SHPRH (SNF2, histone-linker, PHD and RING finger domain-containing helicase), both ubiquitin ligases, are involved in several DDT mechanisms; DNA translesion synthesis (TLS), fork reversal/remodeling and template switch (TS). Here we show that these two human RAD5 homologs contain functional APIM PCNA interacting motifs. Our results show that both the role of HLTF in TLS in HLTF overexpressing cells, and nuclear localization of SHPRH, are dependent on interaction of HLTF and SHPRH with PCNA. Additionally, we detected multiple changes in the mutation spectra when APIM in overexpressed HLTF or SHPRH were mutated compared to overexpressed wild type proteins. In plasmids from cells overexpressing the APIM mutant version of HLTF, we observed a decrease in C to T transitions, the most common mutation caused by UV irradiation, and an increase in mutations on the transcribed strand. These results strongly suggest that direct binding of HLTF and SHPRH to PCNA is vital for their function in DDT.

Mammalian INO80 chromatin remodeler cooperates with FANCM to mediate DNA interstrand crosslink-induced checkpoint activation and repair

DNA Repair ◽  
2019 ◽  
Vol 74 ◽  
pp. 38-50 ◽  
Author(s):  
Veselin Andreev ◽  
Rossitsa Hristova ◽  
Mila Asparuhova ◽  
Georgi Danovski ◽  
Stoyno Stoynov ◽  
...  
Keyword(s):  
Chromatin Remodeler ◽  
Checkpoint Activation ◽  
Interstrand Crosslink

SGS1, the Saccharomyces cerevisiae homologue of BLM and WRN, suppresses genome instability and homeologous recombination

10.1038/83673 ◽  
2001 ◽  
Vol 27 (1) ◽  
pp. 113-116 ◽  
Author(s):  
Kyungjae Myung ◽  
Abhijit Datta ◽  
Clark Chen ◽  
Richard D. Kolodner
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Genome Instability ◽  
Homeologous Recombination

scholarly journals Srs2 Plays a Critical Role in Reversible G2 Arrest upon Chronic and Low Doses of UV Irradiation via Two Distinct Homologous Recombination-Dependent Mechanisms in Postreplication Repair-Deficient Cells

2010 ◽  
Vol 30 (20) ◽  
pp. 4840-4850 ◽  
Author(s):  
Takashi Hishida ◽  
Yoshihiro Hirade ◽  
Nami Haruta ◽  
Yoshino Kubota ◽  
Hiroshi Iwasaki
Keyword(s):  
Dna Damage ◽  
Homologous Recombination ◽  
Excision Repair ◽  
Critical Role ◽  
Nuclear Antigen ◽  
Dna Damage Tolerance ◽  
Checkpoint Activation ◽  
Postreplication Repair ◽  
Nucleotide Excision ◽  
Proliferating Cell

ABSTRACT Differential posttranslational modification of proliferating cell nuclear antigen (PCNA) by ubiquitin or SUMO plays an important role in coordinating the processes of DNA replication and DNA damage tolerance. Previously it was shown that the loss of RAD6-dependent error-free postreplication repair (PRR) results in DNA damage checkpoint-mediated G2 arrest in cells exposed to chronic low-dose UV radiation (CLUV), whereas wild-type and nucleotide excision repair-deficient cells are largely unaffected. In this study, we report that suppression of homologous recombination (HR) in PRR-deficient cells by Srs2 and PCNA sumoylation is required for checkpoint activation and checkpoint maintenance during CLUV irradiation. Cyclin-dependent kinase (CDK1)-dependent phosphorylation of Srs2 did not influence checkpoint-mediated G2 arrest or maintenance in PRR-deficient cells but was critical for HR-dependent checkpoint recovery following release from CLUV exposure. These results indicate that Srs2 plays an important role in checkpoint-mediated reversible G2 arrest in PRR-deficient cells via two separate HR-dependent mechanisms. The first (required to suppress HR during PRR) is regulated by PCNA sumoylation, whereas the second (required for HR-dependent recovery following CLUV exposure) is regulated by CDK1-dependent phosphorylation.

scholarly journals Functional and Physical Interaction of Yeast Mgs1 with PCNA: Impact on RAD6-Dependent DNA Damage Tolerance

2006 ◽  
Vol 26 (14) ◽  
pp. 5509-5517 ◽  
Author(s):  
Takashi Hishida ◽  
Tomoko Ohya ◽  
Yoshino Kubota ◽  
Yusuke Kamada ◽  
Hideo Shinagawa
Keyword(s):  
Dna Damage ◽  
Posttranslational Modifications ◽  
Cell Cycle Progression ◽  
Damage Tolerance ◽  
Genome Instability ◽  
Dna Helicase ◽  
Nuclear Antigen ◽  
Physical Interaction ◽  
Dna Damage Tolerance ◽  
Exogenous Dna

ABSTRACT Proliferating cell nuclear antigen (PCNA), a sliding clamp required for processive DNA synthesis, provides attachment sites for various other proteins that function in DNA replication, DNA repair, cell cycle progression and chromatin assembly. It has been shown that differential posttranslational modifications of PCNA by ubiquitin or SUMO play a pivotal role in controlling the choice of pathway for rescuing stalled replication forks. Here, we explored the roles of Mgs1 and PCNA in replication fork rescue. We provide evidence that Mgs1 physically associates with PCNA and that Mgs1 helps suppress the RAD6 DNA damage tolerance pathway in the absence of exogenous DNA damage. We also show that PCNA sumoylation inhibits the growth of mgs1 rad18 double mutants, in which PCNA sumoylation and the Srs2 DNA helicase coordinately prevent RAD52-dependent homologous recombination. The proposed roles for Mgs1, Srs2, and modified PCNA during replication arrest highlight the importance of modulating the RAD6 and RAD52 pathways to avoid genome instability.

scholarly journals Participation of the HIM1 gene of yeast Saccharomyces cerevisiae in the error-free branch of post-replicative repair and role Polη in him1-dependent mutagenesis

2020 ◽  
Author(s):  
E. A. Alekseeva ◽  
T. A. Evstyukhina ◽  
V. T. Peshekhonov ◽  
V. G. Korolev
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dna Damage ◽  
Damage Tolerance ◽  
Dna Damage Tolerance ◽  
Uv Mutagenesis ◽  
Gene Encoding ◽  
Yeast Saccharomyces Cerevisiae ◽  
Recombination Repair ◽  
Repair Pathways

Abstract In eukaryotes, DNA damage tolerance (DDT) is determined by two repair pathways, homologous repair recombination (HRR) and a pathway controlled by the RAD6-epistatic group of genes. Monoubiquitylation of PCNA mediates an error-prone pathway, whereas polyubiquitylation stimulates an error-free pathway. The error-free pathway involves components of recombination repair; however, the factors that act in this pathway remain largely unknown. Here, we report that the HIM1 gene participates in error-free DDT. Notably, inactivation RAD30 gene encoding Polη completely suppresses him1-dependent UV mutagenesis. Furthermore, data obtained show a significant role of Polη in him1-dependent mutagenesis, especially at non-bipyrimidine sites (NBP sites). We demonstrate that him1 mutation significantly reduces the efficiency of the induction expression of RNR genes after UV irradiation. Besides, this paper presents evidence that significant increase in the dNTP levels suppress him1-dependent mutagenesis. Our findings show that Polη responsible for him1-dependent mutagenesis.

scholarly journals Defects in homologous recombination repair behind the human diseases: FA and HBOC

2016 ◽  
Vol 23 (10) ◽  
pp. T19-T37 ◽  
Author(s):  
Yoko Katsuki ◽  
Minoru Takata
Keyword(s):  
Ovarian Cancer ◽  
Homologous Recombination ◽  
Molecular Mechanisms ◽  
Genome Instability ◽  
Cancer Therapeutics ◽  
Parp Inhibitors ◽  
Homologous Recombination Repair ◽  
Breast And Ovarian Cancer ◽  
Recombination Repair ◽  
Exciting Development

Hereditary breast and ovarian cancer (HBOC) syndrome and a rare childhood disorder Fanconi anemia (FA) are caused by homologous recombination (HR) defects, and some of the causative genes overlap. Recent studies in this field have led to the exciting development of PARP inhibitors as novel cancer therapeutics and have clarified important mechanisms underlying genome instability and tumor suppression in HR-defective disorders. In this review, we provide an overview of the basic molecular mechanisms governing HR and DNA crosslink repair, highlightingBRCA2, and the intriguing relationship between HBOC and FA.

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