Mutations in the DNA ligase I gene of an individual with immunodeficiencies and cellular hypersensitivity to DNA-damaging agents

Barnes, Deborah E.; Tomkinson, Alan E.; Lehmann, Alan R.; Webster, A. D.; Lindahl, Tomas

doi:10.1016/0092-8674(92)90450-q

Cited by 262 publications

(179 citation statements)

References 41 publications

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“…Sequencing the endogenous LIGI gene from genomic DNA confirmed that all 46BR.1G1 variant cells contained the described homozygous/hemizygous 46BR mutation (Arg-771 to Trp; CGG to TGG) (16) (Fig. 1).…”

Section: Different Hligi Protein Backgrounds In 46brligi Extracts-mentioning

confidence: 95%

“…The mutant allele expressed in SV40-immortalized fibroblasts established from this patient (46BR.1G1) encodes a version of hLigI (hemizygous or homozygous for the Arg-771 to Trp) which maintains only 3-5% of ligase activity compared with the non-mutant hLigI (16). The hLigI-deficient 46BR.1G1 cells are hypomutable by DNA damage (33) but are hypersensitive to killing by DNA alkylating agents (34 -39).…”

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confidence: 99%

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CTG/CAG Repeat Instability Is Modulated by the Levels of Human DNA Ligase I and Its Interaction with Proliferating Cell Nuclear Antigen

Castel

Tomkinson

Pearson

2009

Journal of Biological Chemistry

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Mechanisms contributing to disease-associated trinucleotide repeat instability are poorly understood. DNA ligation is an essential step common to replication and repair, both potential sources of repeat instability. Using derivatives of DNA ligase I (hLigI)-deficient human cells (46BR.1G1), we assessed the effect of hLigI activity, overexpression, and its interaction with proliferating cell nuclear antigen (PCNA) upon the ability to replicate and repair trinucleotide repeats. Compared with LigI ؉/؉ , replication progression through repeats was poor, and repair tracts were broadened beyond the slipped-repeat for all mutant extracts. Increased repeat instability was linked only to hLigI overexpression and expression of a mutant hLigI incapable of interacting with PCNA. The endogenous mutant version of hLigI with reduced ligation activity did not alter instability. We distinguished the DNA processes through which hLigI contributes to trinucleotide instability. The highest levels of repeat instability were observed under the hLigI overexpression and were linked to reduced slipped-DNAs repair efficiencies. Therefore, the replication-mediated instability can partly be attributed to errors during replication but also to the poor repair of slipped-DNAs formed during this process. However, repair efficiencies were unaffected by expression of a PCNA interaction mutant of hLigI, limiting this instability to the replication process. The addition of purified proteins suggests that disruption of LigI and PCNA interactions influences trinucleotide repeat instability. The variable levels of age-and tissue-specific trinucleotide repeat instability observed in myotonic dystrophy patients and transgenic mice may be influenced by varying steady state levels of DNA ligase I in these tissues and during different developmental windows.More than 40 hereditary diseases are caused by gene-specific repeat instability (1). Changes at trinucleotide repeats (TNRs) 3 constitute the largest component of this group, causing at least 15 different human diseases, including myotonic dystrophy (DM1), Huntington disease, and fragile X syndrome (FRAXA). Repeat changes in humans are expansion-biased and occur both in parent-to-offspring transmissions and in somatic tissues. The formation of unusual DNA structures during DNA replication and/or aberrant repair of these intermediates has been postulated as the likely source for the development of repeat tract changes (1-3), although the exact molecular mechanisms are unclear. Various proteins have been identified as players in the mutagenic process of TNR instability, including FEN1 (4 -6), OGG1 (7), and some mismatch repair factors, such as MSH2, MSH3, and PMS2 (8 -13). All processes suggested to be involved in repeat instability require a nick located within or proximal to the repeat tract, which ultimately must be ligated. Importantly, many proposed mechanisms of repeat instability involve slippage at the nick (1, 2, 7).Ligation is an essential step in DNA replication, repair, and recombination (14, 1...

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Section: Different Hligi Protein Backgrounds In 46brligi Extracts-mentioning

confidence: 95%

mentioning

confidence: 99%

CTG/CAG Repeat Instability Is Modulated by the Levels of Human DNA Ligase I and Its Interaction with Proliferating Cell Nuclear Antigen

Castel

Tomkinson

Pearson

2009

Journal of Biological Chemistry

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“…Deficient DNA ligase activity causes serious pathologies in host cells. Abnormal accumulation of large DNA replication intermediates in Blooms syndrome cells and accumulation of Okazaki fragments during DNA replication in the DNA ligase I mutant cell line 46BR have been documented (2). Furthermore, since DNA ligases are required to complete any DNA excision repair process, these enzymes must efficiently join nicked DNA duplexes which have been corrected to perfect complementarity, without resealing strand breaks containing damaged or mismatched bases.…”

Section: Introductionmentioning

confidence: 99%

Improving the Fidelity of Thermus Thermophilus DNA Ligase

Luo

Bergstrom

Barany

1996

Nucleic Acids Research

103

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The DNA ligase from Thermus thermophilus (Tth DNA ligase) seals single-strand breaks (nicks) in DNA duplex substrates. The specificity and thermostability of this enzyme are exploited in the ligase chain reaction (LCR) and ligase detection reaction (LDR) to distinguish single base mutations associated with genetic diseases. Herein, we describe a quantitative assay using fluorescently labeled substrates to study the fidelity of Tth DNA ligase. The enzyme exhibits significantly greater discrimination against all single base mismatches on the 3′-side of the nick in comparison with those on the 5′-side of the nick. Among all 12 possible single base pair mismatches on the 3′-side of the nick, only T-G and G-T mismatches generated a quantifiable level of ligation products after 23 h incubation. The high fidelity of Tth DNA ligase can be improved further by introducing a mismatched base or a universal nucleoside analog at the third position of the discriminating oligonucleotide. Finally, two mutant Tth DNA ligases, K294R and K294P, were found to have increased fidelity using this assay.

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“…Similarly, the region of DNA ligase IV containing tandem BRCT motifs is involved in complex formation with the DNA repair protein XRCC4,implicating DNA ligase IV in non-homologous end joining (NHEJ) 1 and V(D)J recombination (13,14). Human individuals with mutations in either the LIG1 (15) or LIG4 gene (16) have been identified. The initial symptoms of the individual with DNA ligase I deficiency were recurrent infections caused by severe combined immunodeficiency (17).…”

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confidence: 99%

Interactions of the DNA Ligase IV-XRCC4 Complex with DNA Ends and the DNA-dependent Protein Kinase

Chen

Trujillo

Sung

et al. 2000

Journal of Biological Chemistry

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204

145

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Three genes encoding DNA ligases, LIG1, LIG3, and LIG4, have been identified in the mammalian genome (1). The products of these genes appear to be responsible for the DNAjoining events that complete DNA replication, genetic recombination, and DNA repair in mammalian cells. In the lower eukaryote Saccharomyces cerevisiae, the DNA ligases encoded by the CDC9 and DNL4 genes are functional homologs of the LIG1 and LIG4 genes. However, this organism apparently lacks a LIG3 gene homolog (2-5).Mammalian DNA ligases consist of a conserved catalytic domain flanked by unrelated sequences (1). It has been suggested that protein-protein interactions mediated by the unique regions flanking the catalytic domain determine the cellular functions of these enzymes. In support of this hypothesis, recent studies have identified specific protein partners for each of the LIG gene products. The non-catalytic N-terminal domain of DNA ligase I interacts with both proliferating cell nuclear antigen and DNA polymerase ␤, implicating this species of DNA ligase in DNA replication and excision repair pathways (6, 7). In contrast, the non-catalytic C-terminal extensions of DNA ligases III␣ and IV contain BRCT motifs (8), a putative protein-protein interaction domain first identified in the protein encoded by the breast cancer susceptibility gene BRCA1 (9, 10). The single BRCT motif of DNA ligase III␣ mediates complex formation with the DNA repair protein XRCC1, linking this species of DNA ligase with base excision repair and the repair of DNA single-strand breaks (11,12). Similarly, the region of DNA ligase IV containing tandem BRCT motifs is involved in complex formation with the DNA repair protein XRCC4,implicating DNA ligase IV in non-homologous end joining (NHEJ) 1 and V(D)J recombination (13, 14). Human individuals with mutations in either the LIG1 (15) or LIG4 gene (16) have been identified. The initial symptoms of the individual with DNA ligase I deficiency were recurrent infections caused by severe combined immunodeficiency (17). Cell lines established from this patient exhibited defects in Okazaki fragment joining and sensitivity to a wide range of DNA-damaging agents, a phenotype consistent with the predicted role of DNA ligase I in DNA replication and excision repair (18,19). When the DNA ligase I-deficient cells were activated for V(D)J recombination by ectopic expression of the RAG proteins, there was no apparent defect in this type of recombination (20,21). However, studies with cell-free extracts suggest that DNA ligase I contributes to the completion of V(D)J recombination (22).The individual with a mutated LIG4 gene presented with leukemia. Unfortunately, attempts to treat this disease with chemotherapy and then ionizing radiation caused a severe reaction (16,23). The extreme radiosensitivity of cell lines established from this individual is consistent with the predicted role of DNA ligase IV in the repair of DNA double-strand breaks by NHEJ. Surprisingly, the DNA ligase IV-deficient individual did not appear to be immunodefi...

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Mutations in the DNA ligase I gene of an individual with immunodeficiencies and cellular hypersensitivity to DNA-damaging agents

Cited by 262 publications

References 41 publications

CTG/CAG Repeat Instability Is Modulated by the Levels of Human DNA Ligase I and Its Interaction with Proliferating Cell Nuclear Antigen

CTG/CAG Repeat Instability Is Modulated by the Levels of Human DNA Ligase I and Its Interaction with Proliferating Cell Nuclear Antigen

Improving the Fidelity of Thermus Thermophilus DNA Ligase

Interactions of the DNA Ligase IV-XRCC4 Complex with DNA Ends and the DNA-dependent Protein Kinase

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