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Muriel W Lambert - One of the best experts on this subject based on the ideXlab platform.
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the Fanconi Anemia Protein fancg binds to the ercc1 xpf endonuclease via its tetratricopeptide repeats and the central domain of ercc1
Biochemistry, 2010Co-Authors: Chuan Wang, Muriel W LambertAbstract:There is evidence that Fanconi Anemia (FA) Proteins play an important role in the repair of DNA interstrand cross-links (ICLs), but the precise mechanism by which this occurs is not clear. One of the critical steps in the ICL repair process involves unhooking of the cross-link from DNA by incisions on one strand on either side of the ICL and its subsequent removal. The ERCC1-XPF endonuclease is involved in this unhooking step and in the removal of the cross-link. We have previously shown that several of the FA Proteins are needed to produce incisions created by ERCC1-XPF at sites of ICLs. To more clearly establish a link between FA Proteins and the incision step(s) mediated by ERCC1-XPF, we undertook yeast two-hybrid analysis to determine whether FANCA, FANCC, FANCF, and FANCG directly interact with ERCC1 and XPF and, if so, to determine the sites of interaction. One of these FA Proteins, FANCG, was found to have a strong affinity for ERCC1 and a moderate affinity for XPF. FANCG has been shown to contain ...
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the Fanconi Anemia Protein fancg binds to the ercc1 xpf endonuclease via its tetratricopeptide repeats and the central domain of ercc1
Biochemistry, 2010Co-Authors: Chuan Wang, Muriel W LambertAbstract:There is evidence that Fanconi Anemia (FA) Proteins play an important role in the repair of DNA interstrand cross-links (ICLs), but the precise mechanism by which this occurs is not clear. One of the critical steps in the ICL repair process involves unhooking of the cross-link from DNA by incisions on one strand on either side of the ICL and its subsequent removal. The ERCC1-XPF endonuclease is involved in this unhooking step and in the removal of the cross-link. We have previously shown that several of the FA Proteins are needed to produce incisions created by ERCC1-XPF at sites of ICLs. To more clearly establish a link between FA Proteins and the incision step(s) mediated by ERCC1-XPF, we undertook yeast two-hybrid analysis to determine whether FANCA, FANCC, FANCF, and FANCG directly interact with ERCC1 and XPF and, if so, to determine the sites of interaction. One of these FA Proteins, FANCG, was found to have a strong affinity for ERCC1 and a moderate affinity for XPF. FANCG has been shown to contain seven tetratricopeptide repeat (TPR) motifs, which are motifs that mediate Protein-Protein interactions. Mapping the sites of interaction of FANCG with ERCC1, using site-directed mutagenesis, demonstrated that TPRs 1, 3, 5, and 6 are needed for binding of FANCG to ERCC1. ERCC1, in turn, was shown to interact with FANCG via its central domain, which is different from the region of ERCC1 that binds to XPF. This binding between FANCG and the ERCC1-XPF endonuclease, combined with our previous studies which show that FANCG is involved in the incision step mediated by ERCC1-XPF, establishes a link between an FA Protein and the critical unhooking step of the ICL repair process.
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the sh3 domain of αii spectrin is a target for the Fanconi Anemia Protein fancg
Biochemistry, 2009Co-Authors: Joel A. Lefferts, Melissa Baralt, Chuan Wang, Deepa Sridharan, Muriel W LambertAbstract:The structural Protein nonerythroid α spectrin (αIISp) plays a role in the repair of DNA interstrand cross-links and is deficient in cells from patients with Fanconi Anemia (FA), in which there is a defect in ability to repair such cross-links. We have proposed a model in which αIISp, whose stability is dependent on FA Proteins, acts as a scaffold to aid in recruitment of repair Proteins to sites of damage. In order to get a clearer understanding of the proposed role of FA Proteins in maintaining stability of αIISp, yeast two-hybrid analysis was carried out to determine whether FA Proteins directly interact with αIISp and, if so, to map the sites of interaction. Four overlapping regions of αIISp were constructed. FANCG interacted with one of these regions and specifically with the SH3 domain in this region of αIISp. The site of interaction in FANCG was mapped to a motif that binds to SH3 domains and contains a consensus sequence with preference for the SH3 domain of αIISp. This site of interaction was con...
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the Fanconi Anemia Protein fancg binds directly to the sh3 domain of aii spectrin and this interaction may play an important role in the stability of aii spectrin and its function in repair of dna interstrand cross links
Blood, 2008Co-Authors: Joel A. Lefferts, Melissa Baralt, Chuan Wang, Muriel W LambertAbstract:Fanconi Anemia (FA) is a genetic disorder characterized by bone marrow failure, a predisposition to cancer, congenital abnormalities and a cellular hypersensitivity to DNA interstrand cross-linking agents. This hypersensitivity in FA cells correlates with a defect in ability to repair interstrand cross-links. We have shown that the structural Protein, nonerythroid a spectrin (aIISp), plays an important role in the repair of DNA interstrand cross-links and that there is a deficiency in aIISp in FA cells. The reduced levels of aIISp in FA cells are due to reduced stability of this Protein. We propose that the stability of aIISp is dependent upon one or more of the FA Proteins. The present study was undertaken in order to get a clearer understanding of the proposed role of FA Proteins in maintaining the stability of aIISp in the cell and the functional importance of this relationship in the repair of DNA interstrand cross-links and the repair defect in FA cells. For these studies, FA Proteins were examined for their ability to directly interact with aIISp and, if so, to map the sites of interaction. Four overlapping regions of aIISp were constructed and binding of FA Proteins to each of these regions was examined using yeast two-hybrid analysis. Of the Proteins examined, FANCG was found to interact with one of these regions of aIISp and specifically with the SH3 domain within this region. The site of interaction in FANCG was mapped to a SH3 domain binding motif, which contains a consensus sequence with preference for the SH3 domain of aIISp. The sites of interaction in both FANCG and aIISp were confirmed using site-directed mutagenesis. Two FA Proteins that did not contain any SH3 binding motifs, FANCC and FANCF, did not interact with the SH3 domain of aIISp or any of the other regions of aIISp. These results thus demonstrate that one of the FA Proteins, FANCG, contains a class of motifs that has specificity for binding to SH3 domains and binds to the SH3 domain of aIISp via this motif. This binding is important in the DNA repair process and in the FA repair defect, as is shown by our in vivo studies in which FA-G cells, transformed with the FANCG cDNA and stably expressing FANCG, showed normal levels of aIISp and a correction of the defect in ability to repair DNA interstrand cross-links. We therefore propose that the binding of FANCG to aIISp is not only important for the stability of aIISp in cells but also for the role aIISp plays in the DNA repair process. Thus a deficiency in FANCG, such as occurs in FA-G cells, could lead to reduced stability of aIISp which in turn could be an important factor in the defective DNA repair pathway in FA cells.
Alan D Dandrea - One of the best experts on this subject based on the ideXlab platform.
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regulation of the Fanconi Anemia pathway by a sumo like delivery network
Genes & Development, 2011Co-Authors: Kailin Yang, Georgelucian Moldovan, Patrizia Vinciguerra, Junko Murai, Shunichi Takeda, Alan D DandreaAbstract:The USP1/UAF1 complex deubiquitinates the Fanconi Anemia Protein FANCD2, thereby promoting homologous recombination and DNA cross-link repair. How USP1/UAF1 is targeted to the FANCD2/FANCI heterodimer has remained unknown. Here we show that UAF1 contains a tandem repeat of SUMO-like domains in its C terminus (SLD1 and SLD2). SLD2 binds directly to a SUMO-like domain-interacting motif (SIM) on FANCI. Deletion of the SLD2 sequence of UAF1 or mutation of the SIM on FANCI disrupts UAF1/FANCI binding and inhibits FANCD2 deubiquitination and DNA repair. The USP1/UAF1 complex also deubiquitinates PCNA-Ub, and deubiquitination requires the PCNA-binding Protein hELG1. The SLD2 sequence of UAF1 binds to a SIM on hELG1, thus targeting the USP1/UAF1 complex to its PCNA-Ub substrate. We propose that the regulated targeting of USP1/UAF1 to its DNA repair substrates, FANCD2-Ub and PCNA-Ub, by SLD-SIM interactions coordinates homologous recombination and translesion DNA synthesis.
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fancd2 hurdles the dna interstrand crosslink
Cell, 2009Co-Authors: Georgelucian Moldovan, Alan D DandreaAbstract:Left unrepaired, DNA interstrand crosslinks represent impassable hurdles for DNA replication, and their removal is a complicated stepwise process involving a variety of enzymes. In a recent paper in Science, Knipscheer et al. (2009) demonstrate that the Fanconi Anemia Protein FANCD2 promotes multiple steps of the crosslink repair process.
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brca1 interacts directly with the Fanconi Anemia Protein fanca
Human Molecular Genetics, 2002Co-Authors: Alexandra Folias, Mara Matkovic, Sonja Reid, James Hejna, Alan D Dandrea, Donald A. Bruun, Markus Grompe, Robb E MosesAbstract:Fanconi Anemia (FA) is a rare autosomal recessive disease characterized by skeletal defects, Anemia, chromosomal instability and increased risk of leukemia. At the cellular level FA is characterized by increased sensitivity to agents forming interstrand crosslinks (ICL) in DNA. Six FA genes have been cloned and interactions among individual FANC Proteins have been found. The FANCD2 Protein co-localizes in nuclear foci with the BRCA1 Protein following DNA damage and during S-phase, requiring the FANCA, C, E and G Proteins to do so. This finding may reflect a direct role for the BRCA1 Protein in double strand break (DSB) repair and interaction with the FANC Proteins. Therefore interactions between BRCA1 and the FANC Proteins were investigated. Among the known FANC Proteins, we find evidence for direct interaction only between the FANCA Protein and BRCA1. The evidence rests on three different tests: yeast two-hybrid analysis, coimmunoprecipitation from in vitro synthesis, and coimmunoprecipitation from cell extracts. The amino terminal portion of FANCA and the central part (aa 740–1083) of BRCA1 contain the sites of interaction. The interaction does not depend on DNA damage, thus FANCA and BRCA1 are constitutively interacting. The demonstrated interaction directly connects BRCA1 to the FA pathway of DNA repair.
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s phase specific interaction of the Fanconi Anemia Protein fancd2 with brca1 and rad51
Blood, 2002Co-Authors: Toshiyasu Taniguchi, Irene Garciahiguera, Alan D Dandrea, Markus Grompe, Paul R. Andreassen, Richard C. GregoryAbstract:Fanconi Anemia (FA) is a human autosomal recessive cancer susceptibility disorder characterized by cellular sensitivity to mitomycin C and defective cell-cycle progression. Six FA genes (corresponding to subtypes A, C, D2, E, F, and G) have been cloned, and the encoded FA Proteins interact in a common pathway. DNA damage activates this pathway, leading to monoubiquitination of the downstream FANCD2 Protein and targeting to nuclear foci containing BRCA1. In the current study, we demonstrate that FANCD2 also undergoes monoubiquitination during S phase of the cell cycle. Monoubiquitinated FANCD2 colocalizes with BRCA1 and RAD51 in S-phase–specific nuclear foci. Monoubiquitination of FANCD2 is required for normal cell-cycle progression following cellular exposure to mitomycin C. Our data indicate that the monoubiquitination of FANCD2 is highly regulated, and they suggest that FANCD2/BRCA1 complexes and FANCD2/RAD51 complexes participate in an S-phase–specific cellular process, such as DNA repair by homologous recombination.
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convergence of the Fanconi Anemia and ataxia telangiectasia signaling pathways
Cell, 2002Co-Authors: Toshiyasu Taniguchi, Irene Garciahiguera, Paul R. Andreassen, Richard C. Gregory, Seongtae Kim, William S Lane, Michael B Kastan, Alan D DandreaAbstract:Fanconi Anemia (FA) and ataxia telangiectasia (AT) are clinically distinct autosomal recessive disorders characterized by spontaneous chromosome breakage and hematological cancers. FA cells are hypersensitive to mitomycin C (MMC), while AT cells are hypersensitive to ionizing radiation (IR). Here, we identify the Fanconi Anemia Protein, FANCD2, as a link between the FA and ATM damage response pathways. ATM phosphorylates FANCD2 on serine 222 in vitro. This site is also phosphorylated in vivo in an ATM-dependent manner following IR. Phosphorylation of FANCD2 is required for activation of an S phase checkpoint. The ATM-dependent phosphorylation of FANCD2 on S222 and the FA pathway-dependent monoubiquitination of FANCD2 on K561 are independent posttranslational modifications regulating discrete cellular signaling pathways. Biallelic disruption of FANCD2 results in both MMC and IR hypersensitivity.
Chuan Wang - One of the best experts on this subject based on the ideXlab platform.
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the Fanconi Anemia Protein fancg binds to the ercc1 xpf endonuclease via its tetratricopeptide repeats and the central domain of ercc1
Biochemistry, 2010Co-Authors: Chuan Wang, Muriel W LambertAbstract:There is evidence that Fanconi Anemia (FA) Proteins play an important role in the repair of DNA interstrand cross-links (ICLs), but the precise mechanism by which this occurs is not clear. One of the critical steps in the ICL repair process involves unhooking of the cross-link from DNA by incisions on one strand on either side of the ICL and its subsequent removal. The ERCC1-XPF endonuclease is involved in this unhooking step and in the removal of the cross-link. We have previously shown that several of the FA Proteins are needed to produce incisions created by ERCC1-XPF at sites of ICLs. To more clearly establish a link between FA Proteins and the incision step(s) mediated by ERCC1-XPF, we undertook yeast two-hybrid analysis to determine whether FANCA, FANCC, FANCF, and FANCG directly interact with ERCC1 and XPF and, if so, to determine the sites of interaction. One of these FA Proteins, FANCG, was found to have a strong affinity for ERCC1 and a moderate affinity for XPF. FANCG has been shown to contain ...
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the Fanconi Anemia Protein fancg binds to the ercc1 xpf endonuclease via its tetratricopeptide repeats and the central domain of ercc1
Biochemistry, 2010Co-Authors: Chuan Wang, Muriel W LambertAbstract:There is evidence that Fanconi Anemia (FA) Proteins play an important role in the repair of DNA interstrand cross-links (ICLs), but the precise mechanism by which this occurs is not clear. One of the critical steps in the ICL repair process involves unhooking of the cross-link from DNA by incisions on one strand on either side of the ICL and its subsequent removal. The ERCC1-XPF endonuclease is involved in this unhooking step and in the removal of the cross-link. We have previously shown that several of the FA Proteins are needed to produce incisions created by ERCC1-XPF at sites of ICLs. To more clearly establish a link between FA Proteins and the incision step(s) mediated by ERCC1-XPF, we undertook yeast two-hybrid analysis to determine whether FANCA, FANCC, FANCF, and FANCG directly interact with ERCC1 and XPF and, if so, to determine the sites of interaction. One of these FA Proteins, FANCG, was found to have a strong affinity for ERCC1 and a moderate affinity for XPF. FANCG has been shown to contain seven tetratricopeptide repeat (TPR) motifs, which are motifs that mediate Protein-Protein interactions. Mapping the sites of interaction of FANCG with ERCC1, using site-directed mutagenesis, demonstrated that TPRs 1, 3, 5, and 6 are needed for binding of FANCG to ERCC1. ERCC1, in turn, was shown to interact with FANCG via its central domain, which is different from the region of ERCC1 that binds to XPF. This binding between FANCG and the ERCC1-XPF endonuclease, combined with our previous studies which show that FANCG is involved in the incision step mediated by ERCC1-XPF, establishes a link between an FA Protein and the critical unhooking step of the ICL repair process.
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the sh3 domain of αii spectrin is a target for the Fanconi Anemia Protein fancg
Biochemistry, 2009Co-Authors: Joel A. Lefferts, Melissa Baralt, Chuan Wang, Deepa Sridharan, Muriel W LambertAbstract:The structural Protein nonerythroid α spectrin (αIISp) plays a role in the repair of DNA interstrand cross-links and is deficient in cells from patients with Fanconi Anemia (FA), in which there is a defect in ability to repair such cross-links. We have proposed a model in which αIISp, whose stability is dependent on FA Proteins, acts as a scaffold to aid in recruitment of repair Proteins to sites of damage. In order to get a clearer understanding of the proposed role of FA Proteins in maintaining stability of αIISp, yeast two-hybrid analysis was carried out to determine whether FA Proteins directly interact with αIISp and, if so, to map the sites of interaction. Four overlapping regions of αIISp were constructed. FANCG interacted with one of these regions and specifically with the SH3 domain in this region of αIISp. The site of interaction in FANCG was mapped to a motif that binds to SH3 domains and contains a consensus sequence with preference for the SH3 domain of αIISp. This site of interaction was con...
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the Fanconi Anemia Protein fancg binds directly to the sh3 domain of aii spectrin and this interaction may play an important role in the stability of aii spectrin and its function in repair of dna interstrand cross links
Blood, 2008Co-Authors: Joel A. Lefferts, Melissa Baralt, Chuan Wang, Muriel W LambertAbstract:Fanconi Anemia (FA) is a genetic disorder characterized by bone marrow failure, a predisposition to cancer, congenital abnormalities and a cellular hypersensitivity to DNA interstrand cross-linking agents. This hypersensitivity in FA cells correlates with a defect in ability to repair interstrand cross-links. We have shown that the structural Protein, nonerythroid a spectrin (aIISp), plays an important role in the repair of DNA interstrand cross-links and that there is a deficiency in aIISp in FA cells. The reduced levels of aIISp in FA cells are due to reduced stability of this Protein. We propose that the stability of aIISp is dependent upon one or more of the FA Proteins. The present study was undertaken in order to get a clearer understanding of the proposed role of FA Proteins in maintaining the stability of aIISp in the cell and the functional importance of this relationship in the repair of DNA interstrand cross-links and the repair defect in FA cells. For these studies, FA Proteins were examined for their ability to directly interact with aIISp and, if so, to map the sites of interaction. Four overlapping regions of aIISp were constructed and binding of FA Proteins to each of these regions was examined using yeast two-hybrid analysis. Of the Proteins examined, FANCG was found to interact with one of these regions of aIISp and specifically with the SH3 domain within this region. The site of interaction in FANCG was mapped to a SH3 domain binding motif, which contains a consensus sequence with preference for the SH3 domain of aIISp. The sites of interaction in both FANCG and aIISp were confirmed using site-directed mutagenesis. Two FA Proteins that did not contain any SH3 binding motifs, FANCC and FANCF, did not interact with the SH3 domain of aIISp or any of the other regions of aIISp. These results thus demonstrate that one of the FA Proteins, FANCG, contains a class of motifs that has specificity for binding to SH3 domains and binds to the SH3 domain of aIISp via this motif. This binding is important in the DNA repair process and in the FA repair defect, as is shown by our in vivo studies in which FA-G cells, transformed with the FANCG cDNA and stably expressing FANCG, showed normal levels of aIISp and a correction of the defect in ability to repair DNA interstrand cross-links. We therefore propose that the binding of FANCG to aIISp is not only important for the stability of aIISp in cells but also for the role aIISp plays in the DNA repair process. Thus a deficiency in FANCG, such as occurs in FA-G cells, could lead to reduced stability of aIISp which in turn could be an important factor in the defective DNA repair pathway in FA cells.
Makoto Futaki - One of the best experts on this subject based on the ideXlab platform.
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the fancg Fanconi Anemia Protein interacts with cyp2e1 possible role in protection against oxidative dna damage
Carcinogenesis, 2002Co-Authors: Makoto Futaki, Sachiko Kajigaya, Shinji Watanabe, Takehito Igarashi, Atsushi Tatsuguchi, Jianxiang WangAbstract:: Fanconi Anemia (FA) is a genetic disorder that leads to aplastic Anemia and birth defects and predisposes to cancer. FA cells exhibit characteristic hypersensitivity to DNA cross-linking agents such as mitomycin C (MMC), and FANCG is one of six known FA gene products. By immunocytochemical analysis of transfected cells, we discovered that although FANCG localized to both the nucleus and cytoplasm, there was an increase in cells with predominantly cytoplasmic staining after treatment with MMC. Concurrently, while searching by two-hybrid analysis for Proteins that associate with FANCG, we identified a novel interaction between FANCG and cytochrome P450 2E1 (CYP2E1). A member of the P450 superfamily, CYP2E1 is associated with the production of reactive oxygen intermediates and the bioactivation of carcinogens. High constitutive levels of CYP2E1 were found in a FA-G lymphoblast cell line, whereas complementation of the FA-G line with wild-type FANCG was associated with decreased CYP2E1. These findings suggested that the interaction of FANCG with CYP2E1 might alter redox metabolism and increase DNA oxidation. Using a fluorescent assay, we found a dose-dependent increase in the oxidized DNA base, 8-oxoguanine (8-oxoG), after treatment of mutant FA-G cells with H(2)O(2) or MMC. Conversely, significantly lower levels of 8-oxoG were detected in FANCG-complemented FA-G cells. We conclude that the unknown function of FANCG involves at least transient interaction with cytoplasmic components, possibly including CYP2E1, and propose a role for FANCG in protection against oxidative DNA damage.
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the fancg Fanconi Anemia Protein interacts with cyp2e1 possible role in protection against oxidative dna damage
Carcinogenesis, 2002Co-Authors: Makoto Futaki, Sachiko Kajigaya, Shinji Watanabe, Takehito Igarashi, Atsushi Tatsuguchi, Jianxiang Wang, Johnson M. LiuAbstract:Fanconi Anemia (FA) is a genetic disorder that leads to aplastic Anemia and birth defects and predisposes to cancer. FA cells exhibit characteristic hypersensitivity to DNA cross-linking agents such as mitomycin C (MMC), and FANCG is one of six known FA gene products. By immunocytochemical analysis of transfected cells, we discovered that although FANCG localized to both the nucleus and cytoplasm, there was an increase in cells with predominantly cytoplasmic staining after treatment with MMC. Concurrently, while searching by two-hybrid analysis for Proteins that associate with FANCG, we identified a novel interaction between FANCG and cytochrome P450 2E1 (CYP2E1). A member of the P450 superfamily, CYP2E1 is associated with the production of reactive oxygen intermediates and the bioactivation of carcinogens. High constitutive levels of CYP2E1 were found in a FA-G lymphoblast cell line, whereas complementation of the FA-G line with wild-type FANCG was associated with decreased CYP2E1. These findings suggested that the interaction of FANCG with CYP2E1 might alter redox metabolism and increase DNA oxidation. Using a fluorescent assay, we found a dose-dependent increase in the oxidized DNA base, 8-oxoguanine (8-oxoG), after treatment of mutant FA-G cells with H 2 O 2 or MMC. Conversely, significantly lower levels of 8-oxoG were detected in FANCG-complemented FA-G cells. We conclude that the unknown function of FANCG involves at least transient interaction with cytoplasmic components, possibly including CYP2E1, and propose a role for FANCG in protection against oxidative DNA damage.
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a cytoplasmic serine Protein kinase binds and may regulate the Fanconi Anemia Protein fanca
Blood, 2001Co-Authors: Hiroshi Yagasaki, Irene Garciahiguera, Daiki Adachi, Makoto Futaki, Nii Tetteh, Alan D Dandrea, Shigetaka Asano, Takayuki YamashitaAbstract:Fanconi Anemia (FA) is an autosomal recessive disease with congenital anomalies, bone marrow failure, and susceptibility to leukemia. Patient cells show chromosome instability and hypersensitivity to DNA cross-linking agents. At least 8 complementation groups (A-G) have been identified and 6 FAgenes (for subtypes A, C, D2, E, F, and G) have been cloned. Increasing evidence indicates that a Protein complex assembly of multiple FA Proteins, including FANCA and FANCG, plays a crucial role in the FA pathway. Previously, it was reported that FANCA was phosphorylated in lymphoblasts from normal controls, whereas the phosphorylation was defective in those derived from patients with FA of multiple complementation groups. The present study examined phosphorylation of FANCA ectopically expressed in FANCA− cells. Several patient-derived mutations abrogated in vivo phosphorylation of FANCA in this system, suggesting that FANCA phosphorylation is associated with its function. In vitro phosphorylation studies indicated that a physiologic Protein kinase for FANCA (FANCA-PK) forms a complex with the substrate. Furthermore, at least a part of FANCA-PK as well as phosphorylated FANCA were included in the FANCA/FANCG complex. Thus, FANCA-PK appears to be another component of the FA Protein complex and may regulate function of FANCA. FANCA-PK was characterized as a cytoplasmic serine kinase sensitive to wortmannin. Identification of the Protein kinase is expected to elucidate regulatory mechanisms that control the FA pathway.
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Fanconi Anemia Protein fancg is a phosphoProtein and is upregulated with fanca after tnf α treatment
Biochemical and Biophysical Research Communications, 2001Co-Authors: Makoto Futaki, Shinji Watanabe, Sachiko KajigayaAbstract:Abstract Fanconi Anemia (FA) is a genetic syndrome characterized by bone marrow failure, birth defects, and a predisposition to malignancy. At this time, six FA genes have been identified, and several gene products have been found to interact in a Protein complex. FA cells appear to overexpress the proinflammatory cytokine, tumor necrosis factor-alpha (TNF-α). We therefore examined the effects of TNF-α on the regulation of FA complementation group Proteins, FANCG and FANCA. We found that treatment with TNF-α induced FANCG Protein expression. FANCA was induced concurrently with FANCG, and the FANCA/FANCG complex was increased in the nucleus following TNF-α treatment. Inactivation of inhibitory kappa B kinase-2 modulated the expression of FANCG. We also found that both nuclear and cytoplasmic FANCG fractions were phosphorylated. These results show that FANCG is a phosphoProtein and suggest that the cellular accumulation of FA Proteins is subject to regulation by TNF-α signaling.
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Fanconi Anemia Protein fancg is a phosphoProtein and is upregulated with fanca after tnf alpha treatment
Biochemical and Biophysical Research Communications, 2001Co-Authors: Makoto Futaki, Sachiko Kajigaya, Shinji Watanabe, Johnson M. LiuAbstract:Abstract Fanconi Anemia (FA) is a genetic syndrome characterized by bone marrow failure, birth defects, and a predisposition to malignancy. At this time, six FA genes have been identified, and several gene products have been found to interact in a Protein complex. FA cells appear to overexpress the proinflammatory cytokine, tumor necrosis factor-alpha (TNF-α). We therefore examined the effects of TNF-α on the regulation of FA complementation group Proteins, FANCG and FANCA. We found that treatment with TNF-α induced FANCG Protein expression. FANCA was induced concurrently with FANCG, and the FANCA/FANCG complex was increased in the nucleus following TNF-α treatment. Inactivation of inhibitory kappa B kinase-2 modulated the expression of FANCG. We also found that both nuclear and cytoplasmic FANCG fractions were phosphorylated. These results show that FANCG is a phosphoProtein and suggest that the cellular accumulation of FA Proteins is subject to regulation by TNF-α signaling.
Johnson M. Liu - One of the best experts on this subject based on the ideXlab platform.
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Fanconi Anemia Protein complex is a novel target of the IKK signalsome
Journal of cellular biochemistry, 2002Co-Authors: Tetsuya Otsuki, Maureen E. Hoatlin, David B. Young, Dennis T. Sasaki, Matthew P. Pando, Anthony M. Manning, Merl F. Hoekstra, Frank Mercurio, Johnson M. LiuAbstract:Fanconi Anemia (FA), a genetic disorder predisposing to aplastic Anemia and cancer, is characterized by hypersensitivity to DNA-damaging agents and oxidative stress. Five of the cloned FA Proteins (FANCA, FANCC, FANCE, FANCF, FANCG) appear to be involved in a common functional pathway that is required for the monoubiquitination of a sixth gene product, FANCD2. Here, we report that FANCA associates with the IκB kinase (IKK) signalsome via interaction with IKK2. Components of the FANCA complex undergo rapid, stimulus-dependent changes in phosphorylation, which are blocked by kinase-inactive IKK2 (IKK2 K > M). When exposed to mitomycin C, cells expressing IKK2 K > M develop a cell cycle abnormality characteristic of FA. Thus, FANCA may function to recruit IKK2, thus providing the cell a means of rapidly responding to stress. J. Cell. Biochem. 86: 613–623, 2002. © 2002 Wiley-Liss, Inc.
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the fancg Fanconi Anemia Protein interacts with cyp2e1 possible role in protection against oxidative dna damage
Carcinogenesis, 2002Co-Authors: Makoto Futaki, Sachiko Kajigaya, Shinji Watanabe, Takehito Igarashi, Atsushi Tatsuguchi, Jianxiang Wang, Johnson M. LiuAbstract:Fanconi Anemia (FA) is a genetic disorder that leads to aplastic Anemia and birth defects and predisposes to cancer. FA cells exhibit characteristic hypersensitivity to DNA cross-linking agents such as mitomycin C (MMC), and FANCG is one of six known FA gene products. By immunocytochemical analysis of transfected cells, we discovered that although FANCG localized to both the nucleus and cytoplasm, there was an increase in cells with predominantly cytoplasmic staining after treatment with MMC. Concurrently, while searching by two-hybrid analysis for Proteins that associate with FANCG, we identified a novel interaction between FANCG and cytochrome P450 2E1 (CYP2E1). A member of the P450 superfamily, CYP2E1 is associated with the production of reactive oxygen intermediates and the bioactivation of carcinogens. High constitutive levels of CYP2E1 were found in a FA-G lymphoblast cell line, whereas complementation of the FA-G line with wild-type FANCG was associated with decreased CYP2E1. These findings suggested that the interaction of FANCG with CYP2E1 might alter redox metabolism and increase DNA oxidation. Using a fluorescent assay, we found a dose-dependent increase in the oxidized DNA base, 8-oxoguanine (8-oxoG), after treatment of mutant FA-G cells with H 2 O 2 or MMC. Conversely, significantly lower levels of 8-oxoG were detected in FANCG-complemented FA-G cells. We conclude that the unknown function of FANCG involves at least transient interaction with cytoplasmic components, possibly including CYP2E1, and propose a role for FANCG in protection against oxidative DNA damage.
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Fanconi Anemia Protein fancg is a phosphoProtein and is upregulated with fanca after tnf alpha treatment
Biochemical and Biophysical Research Communications, 2001Co-Authors: Makoto Futaki, Sachiko Kajigaya, Shinji Watanabe, Johnson M. LiuAbstract:Abstract Fanconi Anemia (FA) is a genetic syndrome characterized by bone marrow failure, birth defects, and a predisposition to malignancy. At this time, six FA genes have been identified, and several gene products have been found to interact in a Protein complex. FA cells appear to overexpress the proinflammatory cytokine, tumor necrosis factor-alpha (TNF-α). We therefore examined the effects of TNF-α on the regulation of FA complementation group Proteins, FANCG and FANCA. We found that treatment with TNF-α induced FANCG Protein expression. FANCA was induced concurrently with FANCG, and the FANCA/FANCG complex was increased in the nucleus following TNF-α treatment. Inactivation of inhibitory kappa B kinase-2 modulated the expression of FANCG. We also found that both nuclear and cytoplasmic FANCG fractions were phosphorylated. These results show that FANCG is a phosphoProtein and suggest that the cellular accumulation of FA Proteins is subject to regulation by TNF-α signaling.
