Regulatory subunit that interacts with and increases the activity of different structure-specific endonucleases. Has several distinct roles in protecting genome stability by resolving diverse forms of deleterious DNA structures originating from replication and recombination intermediates and from DNA damage. Component of the SLX1-SLX4 structure-specific endonuclease that resolves DNA secondary structures generated during DNA repair and recombination. Has endonuclease activity towards branched DNA substrates, introducing single-strand cuts in duplex DNA close to junctions with ss-DNA. Has a preference for 5'-flap structures, and promotes symmetrical cleavage of static and migrating Holliday junctions (HJs). Resolves HJs by generating two pairs of ligatable, nicked duplex products. Interacts with the structure-specific ERCC4-ERCC1 endonuclease and promotes the cleavage of bubble structures. Interacts with the structure-specific MUS81-EME1 endonuclease and promotes the cleavage of 3'-flap and replication fork-like structures. SLX4 is required for recovery from alkylation-induced DNA damage and is involved in the resolution of DNA double-strand breaks.
Structure-specific endonucleases resolve DNA secondary structures generated during DNA repair and recombination. The yeast 5' flap endonuclease Slx1-Slx4 has received particular attention with the finding that Slx4 has Slx1-independent key functions in genome maintenance. Although Slx1 is a highly conserved protein in eukaryotes, no orthologs of Slx4 were reported other than in fungi. Here we report the identification of Slx4 orthologs in metazoa, including fly MUS312, essential for meiotic recombination, and human BTBD12, an ATM/ATR checkpoint kinase substrate. Human SLX1-SLX4 displays robust Holliday junction resolvase activity in addition to 5' flap endonuclease activity. Depletion of SLX1 and SLX4 results in 53BP1 foci accumulation and H2AX phosphorylation as well as cellular hypersensitivity to MMS. Furthermore, we show that SLX4 binds the XPF(ERCC4) and MUS81 subunits of the XPF-ERCC1 and MUS81-EME1 endonucleases and is required for DNA interstrand crosslink repair. We propose that SLX4 acts as a docking platform for multiple structure-specific endonucleases.
Structure-specific endonucleases mediate cleavage of DNA structures formed during repair of collapsed replication forks and double-strand breaks (DSBs). Here, we identify BTBD12 as the human ortholog of the budding yeast DNA repair factor Slx4p and D. melanogaster MUS312. Human SLX4 forms a multiprotein complex with the ERCC4(XPF)-ERCC1, MUS81-EME1, and SLX1 endonucleases and also associates with MSH2/MSH3 mismatch repair complex, telomere binding complex TERF2(TRF2)-TERF2IP(RAP1), the protein kinase PLK1 and the uncharacterized protein C20orf94. Depletion of SLX4 causes sensitivity to mitomycin C and camptothecin and reduces the efficiency of DSB repair in vivo. SLX4 complexes cleave 3' flap, 5' flap, and replication fork structures; yet unlike other endonucleases associated with SLX4, the SLX1-SLX4 module promotes symmetrical cleavage of static and migrating Holliday junctions (HJs), identifying SLX1-SLX4 as a HJ resolvase. Thus, SLX4 assembles a modular toolkit for repair of specific types of DNA lesions and is critical for cellular responses to replication fork failure.
Budding yeast Slx4 interacts with the structure-specific endonuclease Slx1 to ensure completion of ribosomal DNA replication. Slx4 also interacts with the Rad1-Rad10 endonuclease to control cleavage of 3' flaps during repair of double-strand breaks (DSBs). Here we describe the identification of human SLX4, a scaffold for DNA repair nucleases XPF-ERCC1, MUS81-EME1, and SLX1. SLX4 immunoprecipitates show SLX1-dependent nuclease activity toward Holliday junctions and MUS81-dependent activity toward other branched DNA structures. Furthermore, SLX4 enhances the nuclease activity of SLX1, MUS81, and XPF. Consistent with a role in processing recombination intermediates, cells depleted of SLX4 are hypersensitive to genotoxins that cause DSBs and show defects in the resolution of interstrand crosslink-induced DSBs. Depletion of SLX4 causes a decrease in DSB-induced homologous recombination. These data show that SLX4 is a regulator of structure-specific nucleases and that SLX4 and SLX1 are important regulators of genome stability in human cells.
DNA recombination and repair pathways require structure-specific endonucleases to process DNA structures that include forks, flaps, and Holliday junctions. Previously, we determined that the Drosophila MEI-9-ERCC1 endonuclease interacts with the MUS312 protein to produce meiotic crossovers, and that MUS312 has a MEI-9-independent role in interstrand crosslink (ICL) repair. The importance of MUS312 to pathways crucial for maintaining genomic stability in Drosophila prompted us to search for orthologs in other organisms. Based on sequence, expression pattern, conserved protein-protein interactions, and ICL repair function, we determined that the mammalian ortholog of MUS312 is BTBD12. Orthology between these proteins and S. cerevisiae Slx4 helped identify a conserved interaction with a second structure-specific endonuclease, SLX1. Genetic and biochemical evidence described here and in related papers suggest that MUS312 and BTBD12 direct Holliday junction resolution by at least two distinct endonucleases in different recombination and repair contexts.
Catalysis of the cleavage of a 3' flap structure in DNA, but not other DNA structures; processes the 3' ends of Okazaki fragments in lagging strand DNA synthesis.
Budding yeast Slx4 interacts with the structure-specific endonuclease Slx1 to ensure completion of ribosomal DNA replication. Slx4 also interacts with the Rad1-Rad10 endonuclease to control cleavage of 3' flaps during repair of double-strand breaks (DSBs). Here we describe the identification of human SLX4, a scaffold for DNA repair nucleases XPF-ERCC1, MUS81-EME1, and SLX1. SLX4 immunoprecipitates show SLX1-dependent nuclease activity toward Holliday junctions and MUS81-dependent activity toward other branched DNA structures. Furthermore, SLX4 enhances the nuclease activity of SLX1, MUS81, and XPF. Consistent with a role in processing recombination intermediates, cells depleted of SLX4 are hypersensitive to genotoxins that cause DSBs and show defects in the resolution of interstrand crosslink-induced DSBs. Depletion of SLX4 causes a decrease in DSB-induced homologous recombination. These data show that SLX4 is a regulator of structure-specific nucleases and that SLX4 and SLX1 are important regulators of genome stability in human cells.
Structure-specific endonucleases mediate cleavage of DNA structures formed during repair of collapsed replication forks and double-strand breaks (DSBs). Here, we identify BTBD12 as the human ortholog of the budding yeast DNA repair factor Slx4p and D. melanogaster MUS312. Human SLX4 forms a multiprotein complex with the ERCC4(XPF)-ERCC1, MUS81-EME1, and SLX1 endonucleases and also associates with MSH2/MSH3 mismatch repair complex, telomere binding complex TERF2(TRF2)-TERF2IP(RAP1), the protein kinase PLK1 and the uncharacterized protein C20orf94. Depletion of SLX4 causes sensitivity to mitomycin C and camptothecin and reduces the efficiency of DSB repair in vivo. SLX4 complexes cleave 3' flap, 5' flap, and replication fork structures; yet unlike other endonucleases associated with SLX4, the SLX1-SLX4 module promotes symmetrical cleavage of static and migrating Holliday junctions (HJs), identifying SLX1-SLX4 as a HJ resolvase. Thus, SLX4 assembles a modular toolkit for repair of specific types of DNA lesions and is critical for cellular responses to replication fork failure.
Catalysis of the cleavage of a 5' flap structure in DNA, but not other DNA structures; processes the 5' ends of Okazaki fragments in lagging strand DNA synthesis.
Structure-specific endonucleases mediate cleavage of DNA structures formed during repair of collapsed replication forks and double-strand breaks (DSBs). Here, we identify BTBD12 as the human ortholog of the budding yeast DNA repair factor Slx4p and D. melanogaster MUS312. Human SLX4 forms a multiprotein complex with the ERCC4(XPF)-ERCC1, MUS81-EME1, and SLX1 endonucleases and also associates with MSH2/MSH3 mismatch repair complex, telomere binding complex TERF2(TRF2)-TERF2IP(RAP1), the protein kinase PLK1 and the uncharacterized protein C20orf94. Depletion of SLX4 causes sensitivity to mitomycin C and camptothecin and reduces the efficiency of DSB repair in vivo. SLX4 complexes cleave 3' flap, 5' flap, and replication fork structures; yet unlike other endonucleases associated with SLX4, the SLX1-SLX4 module promotes symmetrical cleavage of static and migrating Holliday junctions (HJs), identifying SLX1-SLX4 as a HJ resolvase. Thus, SLX4 assembles a modular toolkit for repair of specific types of DNA lesions and is critical for cellular responses to replication fork failure.
Budding yeast Slx4 interacts with the structure-specific endonuclease Slx1 to ensure completion of ribosomal DNA replication. Slx4 also interacts with the Rad1-Rad10 endonuclease to control cleavage of 3' flaps during repair of double-strand breaks (DSBs). Here we describe the identification of human SLX4, a scaffold for DNA repair nucleases XPF-ERCC1, MUS81-EME1, and SLX1. SLX4 immunoprecipitates show SLX1-dependent nuclease activity toward Holliday junctions and MUS81-dependent activity toward other branched DNA structures. Furthermore, SLX4 enhances the nuclease activity of SLX1, MUS81, and XPF. Consistent with a role in processing recombination intermediates, cells depleted of SLX4 are hypersensitive to genotoxins that cause DSBs and show defects in the resolution of interstrand crosslink-induced DSBs. Depletion of SLX4 causes a decrease in DSB-induced homologous recombination. These data show that SLX4 is a regulator of structure-specific nucleases and that SLX4 and SLX1 are important regulators of genome stability in human cells.
Structure-specific endonucleases resolve DNA secondary structures generated during DNA repair and recombination. The yeast 5' flap endonuclease Slx1-Slx4 has received particular attention with the finding that Slx4 has Slx1-independent key functions in genome maintenance. Although Slx1 is a highly conserved protein in eukaryotes, no orthologs of Slx4 were reported other than in fungi. Here we report the identification of Slx4 orthologs in metazoa, including fly MUS312, essential for meiotic recombination, and human BTBD12, an ATM/ATR checkpoint kinase substrate. Human SLX1-SLX4 displays robust Holliday junction resolvase activity in addition to 5' flap endonuclease activity. Depletion of SLX1 and SLX4 results in 53BP1 foci accumulation and H2AX phosphorylation as well as cellular hypersensitivity to MMS. Furthermore, we show that SLX4 binds the XPF(ERCC4) and MUS81 subunits of the XPF-ERCC1 and MUS81-EME1 endonucleases and is required for DNA interstrand crosslink repair. We propose that SLX4 acts as a docking platform for multiple structure-specific endonucleases.
Catalysis of the endonucleolytic cleavage at a junction such as a reciprocal single-stranded crossover between two homologous DNA duplexes (Holliday junction).
Structure-specific endonucleases mediate cleavage of DNA structures formed during repair of collapsed replication forks and double-strand breaks (DSBs). Here, we identify BTBD12 as the human ortholog of the budding yeast DNA repair factor Slx4p and D. melanogaster MUS312. Human SLX4 forms a multiprotein complex with the ERCC4(XPF)-ERCC1, MUS81-EME1, and SLX1 endonucleases and also associates with MSH2/MSH3 mismatch repair complex, telomere binding complex TERF2(TRF2)-TERF2IP(RAP1), the protein kinase PLK1 and the uncharacterized protein C20orf94. Depletion of SLX4 causes sensitivity to mitomycin C and camptothecin and reduces the efficiency of DSB repair in vivo. SLX4 complexes cleave 3' flap, 5' flap, and replication fork structures; yet unlike other endonucleases associated with SLX4, the SLX1-SLX4 module promotes symmetrical cleavage of static and migrating Holliday junctions (HJs), identifying SLX1-SLX4 as a HJ resolvase. Thus, SLX4 assembles a modular toolkit for repair of specific types of DNA lesions and is critical for cellular responses to replication fork failure.
Budding yeast Slx4 interacts with the structure-specific endonuclease Slx1 to ensure completion of ribosomal DNA replication. Slx4 also interacts with the Rad1-Rad10 endonuclease to control cleavage of 3' flaps during repair of double-strand breaks (DSBs). Here we describe the identification of human SLX4, a scaffold for DNA repair nucleases XPF-ERCC1, MUS81-EME1, and SLX1. SLX4 immunoprecipitates show SLX1-dependent nuclease activity toward Holliday junctions and MUS81-dependent activity toward other branched DNA structures. Furthermore, SLX4 enhances the nuclease activity of SLX1, MUS81, and XPF. Consistent with a role in processing recombination intermediates, cells depleted of SLX4 are hypersensitive to genotoxins that cause DSBs and show defects in the resolution of interstrand crosslink-induced DSBs. Depletion of SLX4 causes a decrease in DSB-induced homologous recombination. These data show that SLX4 is a regulator of structure-specific nucleases and that SLX4 and SLX1 are important regulators of genome stability in human cells.
Structure-specific endonucleases resolve DNA secondary structures generated during DNA repair and recombination. The yeast 5' flap endonuclease Slx1-Slx4 has received particular attention with the finding that Slx4 has Slx1-independent key functions in genome maintenance. Although Slx1 is a highly conserved protein in eukaryotes, no orthologs of Slx4 were reported other than in fungi. Here we report the identification of Slx4 orthologs in metazoa, including fly MUS312, essential for meiotic recombination, and human BTBD12, an ATM/ATR checkpoint kinase substrate. Human SLX1-SLX4 displays robust Holliday junction resolvase activity in addition to 5' flap endonuclease activity. Depletion of SLX1 and SLX4 results in 53BP1 foci accumulation and H2AX phosphorylation as well as cellular hypersensitivity to MMS. Furthermore, we show that SLX4 binds the XPF(ERCC4) and MUS81 subunits of the XPF-ERCC1 and MUS81-EME1 endonucleases and is required for DNA interstrand crosslink repair. We propose that SLX4 acts as a docking platform for multiple structure-specific endonucleases.
Structure-specific endonucleases mediate cleavage of DNA structures formed during repair of collapsed replication forks and double-strand breaks (DSBs). Here, we identify BTBD12 as the human ortholog of the budding yeast DNA repair factor Slx4p and D. melanogaster MUS312. Human SLX4 forms a multiprotein complex with the ERCC4(XPF)-ERCC1, MUS81-EME1, and SLX1 endonucleases and also associates with MSH2/MSH3 mismatch repair complex, telomere binding complex TERF2(TRF2)-TERF2IP(RAP1), the protein kinase PLK1 and the uncharacterized protein C20orf94. Depletion of SLX4 causes sensitivity to mitomycin C and camptothecin and reduces the efficiency of DSB repair in vivo. SLX4 complexes cleave 3' flap, 5' flap, and replication fork structures; yet unlike other endonucleases associated with SLX4, the SLX1-SLX4 module promotes symmetrical cleavage of static and migrating Holliday junctions (HJs), identifying SLX1-SLX4 as a HJ resolvase. Thus, SLX4 assembles a modular toolkit for repair of specific types of DNA lesions and is critical for cellular responses to replication fork failure.
Interacting selectively and non-covalently with any protein or protein complex (a complex of two or more proteins that may include other nonprotein molecules).
Evidence
1:
Inferred from Physical InteractionUniProtKB
Structure-specific endonucleases resolve DNA secondary structures generated during DNA repair and recombination. The yeast 5' flap endonuclease Slx1-Slx4 has received particular attention with the finding that Slx4 has Slx1-independent key functions in genome maintenance. Although Slx1 is a highly conserved protein in eukaryotes, no orthologs of Slx4 were reported other than in fungi. Here we report the identification of Slx4 orthologs in metazoa, including fly MUS312, essential for meiotic recombination, and human BTBD12, an ATM/ATR checkpoint kinase substrate. Human SLX1-SLX4 displays robust Holliday junction resolvase activity in addition to 5' flap endonuclease activity. Depletion of SLX1 and SLX4 results in 53BP1 foci accumulation and H2AX phosphorylation as well as cellular hypersensitivity to MMS. Furthermore, we show that SLX4 binds the XPF(ERCC4) and MUS81 subunits of the XPF-ERCC1 and MUS81-EME1 endonucleases and is required for DNA interstrand crosslink repair. We propose that SLX4 acts as a docking platform for multiple structure-specific endonucleases.
Evidence
2:
Inferred from Physical InteractionUniProtKB
DNA recombination and repair pathways require structure-specific endonucleases to process DNA structures that include forks, flaps, and Holliday junctions. Previously, we determined that the Drosophila MEI-9-ERCC1 endonuclease interacts with the MUS312 protein to produce meiotic crossovers, and that MUS312 has a MEI-9-independent role in interstrand crosslink (ICL) repair. The importance of MUS312 to pathways crucial for maintaining genomic stability in Drosophila prompted us to search for orthologs in other organisms. Based on sequence, expression pattern, conserved protein-protein interactions, and ICL repair function, we determined that the mammalian ortholog of MUS312 is BTBD12. Orthology between these proteins and S. cerevisiae Slx4 helped identify a conserved interaction with a second structure-specific endonuclease, SLX1. Genetic and biochemical evidence described here and in related papers suggest that MUS312 and BTBD12 direct Holliday junction resolution by at least two distinct endonucleases in different recombination and repair contexts.
Evidence
3:
Inferred from Physical InteractionUniProtKB
Structure-specific endonucleases mediate cleavage of DNA structures formed during repair of collapsed replication forks and double-strand breaks (DSBs). Here, we identify BTBD12 as the human ortholog of the budding yeast DNA repair factor Slx4p and D. melanogaster MUS312. Human SLX4 forms a multiprotein complex with the ERCC4(XPF)-ERCC1, MUS81-EME1, and SLX1 endonucleases and also associates with MSH2/MSH3 mismatch repair complex, telomere binding complex TERF2(TRF2)-TERF2IP(RAP1), the protein kinase PLK1 and the uncharacterized protein C20orf94. Depletion of SLX4 causes sensitivity to mitomycin C and camptothecin and reduces the efficiency of DSB repair in vivo. SLX4 complexes cleave 3' flap, 5' flap, and replication fork structures; yet unlike other endonucleases associated with SLX4, the SLX1-SLX4 module promotes symmetrical cleavage of static and migrating Holliday junctions (HJs), identifying SLX1-SLX4 as a HJ resolvase. Thus, SLX4 assembles a modular toolkit for repair of specific types of DNA lesions and is critical for cellular responses to replication fork failure.
Evidence
4:
Inferred from Physical InteractionUniProtKB
Budding yeast Slx4 interacts with the structure-specific endonuclease Slx1 to ensure completion of ribosomal DNA replication. Slx4 also interacts with the Rad1-Rad10 endonuclease to control cleavage of 3' flaps during repair of double-strand breaks (DSBs). Here we describe the identification of human SLX4, a scaffold for DNA repair nucleases XPF-ERCC1, MUS81-EME1, and SLX1. SLX4 immunoprecipitates show SLX1-dependent nuclease activity toward Holliday junctions and MUS81-dependent activity toward other branched DNA structures. Furthermore, SLX4 enhances the nuclease activity of SLX1, MUS81, and XPF. Consistent with a role in processing recombination intermediates, cells depleted of SLX4 are hypersensitive to genotoxins that cause DSBs and show defects in the resolution of interstrand crosslink-induced DSBs. Depletion of SLX4 causes a decrease in DSB-induced homologous recombination. These data show that SLX4 is a regulator of structure-specific nucleases and that SLX4 and SLX1 are important regulators of genome stability in human cells.
DNA double-strand break processing involved in repair via single-strand annealingdefinition[GO:0010792]
The 5' to 3' exonucleolytic resection of the DNA at the site of the break to form a 3' single-strand DNA overhang that results in the repair of a double strand break via single-strand annealing.
Evidence
1:
Inferred from Mutant PhenotypeUniProtKB
Budding yeast Slx4 interacts with the structure-specific endonuclease Slx1 to ensure completion of ribosomal DNA replication. Slx4 also interacts with the Rad1-Rad10 endonuclease to control cleavage of 3' flaps during repair of double-strand breaks (DSBs). Here we describe the identification of human SLX4, a scaffold for DNA repair nucleases XPF-ERCC1, MUS81-EME1, and SLX1. SLX4 immunoprecipitates show SLX1-dependent nuclease activity toward Holliday junctions and MUS81-dependent activity toward other branched DNA structures. Furthermore, SLX4 enhances the nuclease activity of SLX1, MUS81, and XPF. Consistent with a role in processing recombination intermediates, cells depleted of SLX4 are hypersensitive to genotoxins that cause DSBs and show defects in the resolution of interstrand crosslink-induced DSBs. Depletion of SLX4 causes a decrease in DSB-induced homologous recombination. These data show that SLX4 is a regulator of structure-specific nucleases and that SLX4 and SLX1 are important regulators of genome stability in human cells.
The process of restoring DNA after damage. Genomes are subject to damage by chemical and physical agents in the environment (e.g. UV and ionizing radiations, chemical mutagens, fungal and bacterial toxins, etc.) and by free radicals or alkylating agents endogenously generated in metabolism. DNA is also damaged because of errors during its replication. A variety of different DNA repair pathways have been reported that include direct reversal, base excision repair, nucleotide excision repair, photoreactivation, bypass, double-strand break repair pathway, and mismatch repair pathway.
Evidence
1:
Inferred from Mutant PhenotypeUniProtKB
DNA recombination and repair pathways require structure-specific endonucleases to process DNA structures that include forks, flaps, and Holliday junctions. Previously, we determined that the Drosophila MEI-9-ERCC1 endonuclease interacts with the MUS312 protein to produce meiotic crossovers, and that MUS312 has a MEI-9-independent role in interstrand crosslink (ICL) repair. The importance of MUS312 to pathways crucial for maintaining genomic stability in Drosophila prompted us to search for orthologs in other organisms. Based on sequence, expression pattern, conserved protein-protein interactions, and ICL repair function, we determined that the mammalian ortholog of MUS312 is BTBD12. Orthology between these proteins and S. cerevisiae Slx4 helped identify a conserved interaction with a second structure-specific endonuclease, SLX1. Genetic and biochemical evidence described here and in related papers suggest that MUS312 and BTBD12 direct Holliday junction resolution by at least two distinct endonucleases in different recombination and repair contexts.
The error-free repair of a double-strand break in DNA in which the broken DNA molecule is repaired using homologous sequences. A strand in the broken DNA searches for a homologous region in an intact chromosome to serve as the template for DNA synthesis. The restoration of two intact DNA molecules results in the exchange, reciprocal or nonreciprocal, of genetic material between the intact DNA molecule and the broken DNA molecule.
Evidence
1:
Inferred from Mutant PhenotypeUniProtKB
Budding yeast Slx4 interacts with the structure-specific endonuclease Slx1 to ensure completion of ribosomal DNA replication. Slx4 also interacts with the Rad1-Rad10 endonuclease to control cleavage of 3' flaps during repair of double-strand breaks (DSBs). Here we describe the identification of human SLX4, a scaffold for DNA repair nucleases XPF-ERCC1, MUS81-EME1, and SLX1. SLX4 immunoprecipitates show SLX1-dependent nuclease activity toward Holliday junctions and MUS81-dependent activity toward other branched DNA structures. Furthermore, SLX4 enhances the nuclease activity of SLX1, MUS81, and XPF. Consistent with a role in processing recombination intermediates, cells depleted of SLX4 are hypersensitive to genotoxins that cause DSBs and show defects in the resolution of interstrand crosslink-induced DSBs. Depletion of SLX4 causes a decrease in DSB-induced homologous recombination. These data show that SLX4 is a regulator of structure-specific nucleases and that SLX4 and SLX1 are important regulators of genome stability in human cells.
Evidence
2:
Inferred from Mutant PhenotypeUniProtKB
Structure-specific endonucleases mediate cleavage of DNA structures formed during repair of collapsed replication forks and double-strand breaks (DSBs). Here, we identify BTBD12 as the human ortholog of the budding yeast DNA repair factor Slx4p and D. melanogaster MUS312. Human SLX4 forms a multiprotein complex with the ERCC4(XPF)-ERCC1, MUS81-EME1, and SLX1 endonucleases and also associates with MSH2/MSH3 mismatch repair complex, telomere binding complex TERF2(TRF2)-TERF2IP(RAP1), the protein kinase PLK1 and the uncharacterized protein C20orf94. Depletion of SLX4 causes sensitivity to mitomycin C and camptothecin and reduces the efficiency of DSB repair in vivo. SLX4 complexes cleave 3' flap, 5' flap, and replication fork structures; yet unlike other endonucleases associated with SLX4, the SLX1-SLX4 module promotes symmetrical cleavage of static and migrating Holliday junctions (HJs), identifying SLX1-SLX4 as a HJ resolvase. Thus, SLX4 assembles a modular toolkit for repair of specific types of DNA lesions and is critical for cellular responses to replication fork failure.
A DNA repair process in which a small region of the strand surrounding the damage is removed from the DNA helix as an oligonucleotide. The small gap left in the DNA helix is filled in by the sequential action of DNA polymerase and DNA ligase. Nucleotide excision repair recognizes a wide range of substrates, including damage caused by UV irradiation (pyrimidine dimers and 6-4 photoproducts) and chemicals (intrastrand cross-links and bulky adducts).
Evidence
1:
Inferred from Mutant PhenotypeUniProtKB
Structure-specific endonucleases resolve DNA secondary structures generated during DNA repair and recombination. The yeast 5' flap endonuclease Slx1-Slx4 has received particular attention with the finding that Slx4 has Slx1-independent key functions in genome maintenance. Although Slx1 is a highly conserved protein in eukaryotes, no orthologs of Slx4 were reported other than in fungi. Here we report the identification of Slx4 orthologs in metazoa, including fly MUS312, essential for meiotic recombination, and human BTBD12, an ATM/ATR checkpoint kinase substrate. Human SLX1-SLX4 displays robust Holliday junction resolvase activity in addition to 5' flap endonuclease activity. Depletion of SLX1 and SLX4 results in 53BP1 foci accumulation and H2AX phosphorylation as well as cellular hypersensitivity to MMS. Furthermore, we show that SLX4 binds the XPF(ERCC4) and MUS81 subunits of the XPF-ERCC1 and MUS81-EME1 endonucleases and is required for DNA interstrand crosslink repair. We propose that SLX4 acts as a docking platform for multiple structure-specific endonucleases.
Structure-specific endonucleases mediate cleavage of DNA structures formed during repair of collapsed replication forks and double-strand breaks (DSBs). Here, we identify BTBD12 as the human ortholog of the budding yeast DNA repair factor Slx4p and D. melanogaster MUS312. Human SLX4 forms a multiprotein complex with the ERCC4(XPF)-ERCC1, MUS81-EME1, and SLX1 endonucleases and also associates with MSH2/MSH3 mismatch repair complex, telomere binding complex TERF2(TRF2)-TERF2IP(RAP1), the protein kinase PLK1 and the uncharacterized protein C20orf94. Depletion of SLX4 causes sensitivity to mitomycin C and camptothecin and reduces the efficiency of DSB repair in vivo. SLX4 complexes cleave 3' flap, 5' flap, and replication fork structures; yet unlike other endonucleases associated with SLX4, the SLX1-SLX4 module promotes symmetrical cleavage of static and migrating Holliday junctions (HJs), identifying SLX1-SLX4 as a HJ resolvase. Thus, SLX4 assembles a modular toolkit for repair of specific types of DNA lesions and is critical for cellular responses to replication fork failure.
Protein induced by DNA damage or protein involved in the response to DNA damage. Drug- or radiation-induced injuries in DNA introduce deviations from its normal double-helical conformation. These changes include structural distortions which interfere with replication and transcription, as well as point mutations which disrupt base pairs and exert damaging effects on future generations through changes in DNA sequence. Response to DNA damage results in either repair or tolerance.
Protein involved in the repair of DNA, the various biochemical processes by which damaged DNA can be restored. DNA repair embraces, for instance, not only the direct reversal of some types of damage (such as the enzymatic photoreactivation of thymine dimers), but also multiple distinct mechanisms for excising damaged base; termed nucleotide excision repair (NER), base excision repair (BER) and mismatch repair (MMR); or mechanisms for repairing double-strand breaks.
A reference proteome is a set of protein sequences derived from a complete proteome which constitutes a defined standard for a particular user community. Reference proteomes are manually defined according to a number of criteria. They cover the proteomes of well- studied model organisms and other proteomes of interest for biomedical and biotechnological research. Reference proteomes have been selected to provide broad coverage of the tree of life, and constitute a representative cross-section of the taxonomic diversity to be found within UniProtKB.