The Experts below are selected from a list of 138 Experts worldwide ranked by ideXlab platform
Masatsune Kainosho - One of the best experts on this subject based on the ideXlab platform.
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Alternative SAIL-Trp for robust aromatic signal assignment and determination of the χ_2 conformation by intra-residue NOEs
Journal of Biomolecular NMR, 2011Co-Authors: Yohei Miyanoiri, Tsutomu Terauchi, Kosuke Okuma, Mitsuhiro Takeda, Masatsune KainoshoAbstract:Tryptophan (Trp) residues are frequently found in the hydrophobic cores of Proteins, and therefore, their side-chain conformations, especially the precise locations of the bulky indole rings, are critical for determining structures by NMR. However, when analyzing [U–^13C,^15N]-Proteins, the observation and assignment of the ring signals are often hampered by excessive overlaps and tight spin couplings. These difficulties have been greatly alleviated by using stereo-array isotope labeled (SAIL) Proteins, which are composed of isotope-labeled amino acids optimized for unambiguous side-chain NMR assignment, exclusively through the ^13C–^13C and ^13C–^1H spin coupling networks (Kainosho et al. in Nature 440:52–57, 2006 ). In this paper, we propose an alternative type of SAIL-Trp with the [ζ2,ζ3-^2H_2; δ1,ε3,η2-^13C_3; ε1-^15N]-indole ring ([^12C _γ, ^ 12 C_ε2] SAIL-Trp), which provides a more robust way to correlate the ^1H_β, ^1H_α, and ^1H_N to the ^1H_δ1 and ^1H_ε3 through the intra-residue NOEs. The assignment of the ^1H_δ1/^13C_δ1 and ^1H_ε3/^13C_ε3 signals can thus be transferred to the ^1H_ε1/^15N_ε1 and ^1H_η2/^13C_η2 signals, as with the previous type of SAIL-Trp, which has an extra ^13C at the C_γ of the ring. By taking advantage of the stereospecific deuteration of one of the prochiral β-methylene protons, which was ^1H_β2 in this experiment, one can determine the side-chain conformation of the Trp residue including the χ_2 angle, which is especially important for Trp residues, as they can adopt three preferred conformations. We demonstrated the usefulness of [^12C_γ,^12C_ε2] SAIL-Trp for the 12 kDa DNA binding domain of mouse c-Myb Protein (Myb-R2R3), which contains six Trp residues.
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alternative sail trp for robust aromatic signal assignment and determination of the χ 2 conformation by intra residue noes
Journal of Biomolecular NMR, 2011Co-Authors: Yohei Miyanoiri, Tsutomu Terauchi, Kosuke Okuma, Masatsune Kainosho, Mitsuhiro TakedaAbstract:Tryptophan (Trp) residues are frequently found in the hydrophobic cores of Proteins, and therefore, their side-chain conformations, especially the precise locations of the bulky indole rings, are critical for determining structures by NMR. However, when analyzing [U–13C,15N]-Proteins, the observation and assignment of the ring signals are often hampered by excessive overlaps and tight spin couplings. These difficulties have been greatly alleviated by using stereo-array isotope labeled (SAIL) Proteins, which are composed of isotope-labeled amino acids optimized for unambiguous side-chain NMR assignment, exclusively through the 13C–13C and 13C–1H spin coupling networks (Kainosho et al. in Nature 440:52–57, 2006). In this paper, we propose an alternative type of SAIL-Trp with the [ζ2,ζ3-2H2; δ1,e3,η2-13C3; e1-15N]-indole ring ([12C γ, 12 Ce2] SAIL-Trp), which provides a more robust way to correlate the 1Hβ, 1Hα, and 1HN to the 1Hδ1 and 1He3 through the intra-residue NOEs. The assignment of the 1Hδ1/13Cδ1 and 1He3/13Ce3 signals can thus be transferred to the 1He1/15Ne1 and 1Hη2/13Cη2 signals, as with the previous type of SAIL-Trp, which has an extra 13C at the Cγ of the ring. By taking advantage of the stereospecific deuteration of one of the prochiral β-methylene protons, which was 1Hβ2 in this experiment, one can determine the side-chain conformation of the Trp residue including the χ2 angle, which is especially important for Trp residues, as they can adopt three preferred conformations. We demonstrated the usefulness of [12Cγ,12Ce2] SAIL-Trp for the 12 kDa DNA binding domain of mouse c-Myb Protein (Myb-R2R3), which contains six Trp residues.
Junn Yanagisawa - One of the best experts on this subject based on the ideXlab platform.
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the nucleolar Protein Myb binding Protein 1a Mybbp1a enhances p53 tetramerization and acetylation in response to nucleolar disruption
Journal of Biological Chemistry, 2014Co-Authors: Wakana Ono, Kensuke Akaogi, Tsuyoshi Waku, Takao Kuroda, Wataru Yokoyama, Yuki Hayashi, Keiji Kimura, Hiroyuki Kishimoto, Ichiaki Ito, Junn YanagisawaAbstract:Tetramerization of p53 is crucial to exert its biological activity, and nucleolar disruption is sufficient to activate p53. We previously demonstrated that nucleolar stress induces translocation of the nucleolar Protein MybBP1A from the nucleolus to the nucleoplasm and enhances p53 activity. However, whether and how MybBP1A regulates p53 tetramerization in response to nucleolar stress remain unclear. In this study, we demonstrated that MybBP1A enhances p53 tetramerization, followed by acetylation under nucleolar stress. We found that MybBP1A has two regions that directly bind to lysine residues of the p53 C-terminal regulatory domain. MybBP1A formed a self-assembled complex that provided a molecular platform for p53 tetramerization and enhanced p300-mediated acetylation of the p53 tetramer. Moreover, our results show that MybBP1A functions to enhance p53 tetramerization that is necessary for p53 activation, followed by cell death with actinomycin D treatment. Thus, we suggest that MybBP1A plays a pivotal role in the cellular stress response.
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Nucleolar Protein, Myb-binding Protein 1A, specifically binds to nonacetylated p53 and efficiently promotes transcriptional activation.
Biochemical and biophysical research communications, 2013Co-Authors: Wakana Ono, Kensuke Akaogi, Tsuyoshi Waku, Takao Kuroda, Wataru Yokoyama, Yuki Hayashi, Keiji Kimura, Hiroyuki Kishimoto, Junn YanagisawaAbstract:Nucleolar dynamics are important for cellular stress response. We previously demonstrated that nucleolar stress induces nucleolar Protein Myb-binding Protein 1A (MybBP1A) translocation from the nucleolus to the nucleoplasm and enhances p53 activity. However, the underlying molecular mechanism is understood to a lesser extent. Here we demonstrate that MybBP1A interacts with lysine residues in the C-terminal regulatory domain region of p53. MybBP1A specifically interacts with nonacetylated p53 and induces p53 acetylation. We propose that MybBP1A dissociates from acetylated p53 because MybBP1A did not interact with acetylated p53 and because MybBP1A was not recruited to the p53 target promoter. Therefore, once p53 is acetylated, MybBP1A dissociates from p53 and interacts with nonacetylated p53, which enables another cycle of p53 activation. Based on our observations, this MybBP1A-p53 binding property can account for efficient p53-activation by MybBP1A under nucleolar stress. Our results support the idea that MybBP1A plays catalytic roles in p53 acetylation and activation.
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MybBP1A suppresses breast cancer tumorigenesis by enhancing the p53 dependent anoikis
BMC cancer, 2013Co-Authors: Kensuke Akaogi, Wakana Ono, Yuki Hayashi, Hiroyuki Kishimoto, Junn YanagisawaAbstract:Background Tumor suppressor p53 is mutated in a wide variety of human cancers and plays a critical role in anoikis, which is essential for preventing tumorigenesis. Recently, we found that a nucleolar Protein, Myb-binding Protein 1a (MybBP1A), was involved in p53 activation. However, the function of MybBP1A in cancer prevention has not been elucidated.
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MybBP1A suppresses breast cancer tumorigenesis by enhancing the p53 dependent anoikis
BMC Cancer, 2013Co-Authors: Kensuke Akaogi, Wakana Ono, Yuki Hayashi, Hiroyuki Kishimoto, Junn YanagisawaAbstract:Background Tumor suppressor p53 is mutated in a wide variety of human cancers and plays a critical role in anoikis, which is essential for preventing tumorigenesis. Recently, we found that a nucleolar Protein, Myb-binding Protein 1a (MybBP1A), was involved in p53 activation. However, the function of MybBP1A in cancer prevention has not been elucidated. Methods Relationships between MybBP1A expression levels and breast cancer progression were examined using patient microarray databases and tissue microarrays. Colony formation, xenograft, and anoikis assays were conducted using cells in which MybBP1A was either knocked down or overexpressed. p53 activation and interactions between p53 and MybBP1A were assessed by immunoprecipitation and western blot. Results MybBP1A expression was negatively correlated with breast cancer tumorigenesis. In vivo and in vitro experiments using the breast cancer cell lines MCF-7 and ZR-75-1, which expresses wild type p53, showed that tumorigenesis, colony formation, and anoikis resistance were significantly enhanced by MybBP1A knockdown. We also found that MybBP1A binds to p53 and enhances p53 target gene transcription under anoikis conditions. Conclusions These results suggest that MybBP1A is required for p53 activation during anoikis; therefore, it is involved in suppressing colony formation and the tumorigenesis of breast cancer cells. Collectively, our results suggest that MybBP1A plays a role in tumor prevention in the context of p53 activation.
Tsutomu Terauchi - One of the best experts on this subject based on the ideXlab platform.
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Alternative SAIL-Trp for robust aromatic signal assignment and determination of the χ_2 conformation by intra-residue NOEs
Journal of Biomolecular NMR, 2011Co-Authors: Yohei Miyanoiri, Tsutomu Terauchi, Kosuke Okuma, Mitsuhiro Takeda, Masatsune KainoshoAbstract:Tryptophan (Trp) residues are frequently found in the hydrophobic cores of Proteins, and therefore, their side-chain conformations, especially the precise locations of the bulky indole rings, are critical for determining structures by NMR. However, when analyzing [U–^13C,^15N]-Proteins, the observation and assignment of the ring signals are often hampered by excessive overlaps and tight spin couplings. These difficulties have been greatly alleviated by using stereo-array isotope labeled (SAIL) Proteins, which are composed of isotope-labeled amino acids optimized for unambiguous side-chain NMR assignment, exclusively through the ^13C–^13C and ^13C–^1H spin coupling networks (Kainosho et al. in Nature 440:52–57, 2006 ). In this paper, we propose an alternative type of SAIL-Trp with the [ζ2,ζ3-^2H_2; δ1,ε3,η2-^13C_3; ε1-^15N]-indole ring ([^12C _γ, ^ 12 C_ε2] SAIL-Trp), which provides a more robust way to correlate the ^1H_β, ^1H_α, and ^1H_N to the ^1H_δ1 and ^1H_ε3 through the intra-residue NOEs. The assignment of the ^1H_δ1/^13C_δ1 and ^1H_ε3/^13C_ε3 signals can thus be transferred to the ^1H_ε1/^15N_ε1 and ^1H_η2/^13C_η2 signals, as with the previous type of SAIL-Trp, which has an extra ^13C at the C_γ of the ring. By taking advantage of the stereospecific deuteration of one of the prochiral β-methylene protons, which was ^1H_β2 in this experiment, one can determine the side-chain conformation of the Trp residue including the χ_2 angle, which is especially important for Trp residues, as they can adopt three preferred conformations. We demonstrated the usefulness of [^12C_γ,^12C_ε2] SAIL-Trp for the 12 kDa DNA binding domain of mouse c-Myb Protein (Myb-R2R3), which contains six Trp residues.
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alternative sail trp for robust aromatic signal assignment and determination of the χ 2 conformation by intra residue noes
Journal of Biomolecular NMR, 2011Co-Authors: Yohei Miyanoiri, Tsutomu Terauchi, Kosuke Okuma, Masatsune Kainosho, Mitsuhiro TakedaAbstract:Tryptophan (Trp) residues are frequently found in the hydrophobic cores of Proteins, and therefore, their side-chain conformations, especially the precise locations of the bulky indole rings, are critical for determining structures by NMR. However, when analyzing [U–13C,15N]-Proteins, the observation and assignment of the ring signals are often hampered by excessive overlaps and tight spin couplings. These difficulties have been greatly alleviated by using stereo-array isotope labeled (SAIL) Proteins, which are composed of isotope-labeled amino acids optimized for unambiguous side-chain NMR assignment, exclusively through the 13C–13C and 13C–1H spin coupling networks (Kainosho et al. in Nature 440:52–57, 2006). In this paper, we propose an alternative type of SAIL-Trp with the [ζ2,ζ3-2H2; δ1,e3,η2-13C3; e1-15N]-indole ring ([12C γ, 12 Ce2] SAIL-Trp), which provides a more robust way to correlate the 1Hβ, 1Hα, and 1HN to the 1Hδ1 and 1He3 through the intra-residue NOEs. The assignment of the 1Hδ1/13Cδ1 and 1He3/13Ce3 signals can thus be transferred to the 1He1/15Ne1 and 1Hη2/13Cη2 signals, as with the previous type of SAIL-Trp, which has an extra 13C at the Cγ of the ring. By taking advantage of the stereospecific deuteration of one of the prochiral β-methylene protons, which was 1Hβ2 in this experiment, one can determine the side-chain conformation of the Trp residue including the χ2 angle, which is especially important for Trp residues, as they can adopt three preferred conformations. We demonstrated the usefulness of [12Cγ,12Ce2] SAIL-Trp for the 12 kDa DNA binding domain of mouse c-Myb Protein (Myb-R2R3), which contains six Trp residues.
Kosuke Okuma - One of the best experts on this subject based on the ideXlab platform.
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Alternative SAIL-Trp for robust aromatic signal assignment and determination of the χ_2 conformation by intra-residue NOEs
Journal of Biomolecular NMR, 2011Co-Authors: Yohei Miyanoiri, Tsutomu Terauchi, Kosuke Okuma, Mitsuhiro Takeda, Masatsune KainoshoAbstract:Tryptophan (Trp) residues are frequently found in the hydrophobic cores of Proteins, and therefore, their side-chain conformations, especially the precise locations of the bulky indole rings, are critical for determining structures by NMR. However, when analyzing [U–^13C,^15N]-Proteins, the observation and assignment of the ring signals are often hampered by excessive overlaps and tight spin couplings. These difficulties have been greatly alleviated by using stereo-array isotope labeled (SAIL) Proteins, which are composed of isotope-labeled amino acids optimized for unambiguous side-chain NMR assignment, exclusively through the ^13C–^13C and ^13C–^1H spin coupling networks (Kainosho et al. in Nature 440:52–57, 2006 ). In this paper, we propose an alternative type of SAIL-Trp with the [ζ2,ζ3-^2H_2; δ1,ε3,η2-^13C_3; ε1-^15N]-indole ring ([^12C _γ, ^ 12 C_ε2] SAIL-Trp), which provides a more robust way to correlate the ^1H_β, ^1H_α, and ^1H_N to the ^1H_δ1 and ^1H_ε3 through the intra-residue NOEs. The assignment of the ^1H_δ1/^13C_δ1 and ^1H_ε3/^13C_ε3 signals can thus be transferred to the ^1H_ε1/^15N_ε1 and ^1H_η2/^13C_η2 signals, as with the previous type of SAIL-Trp, which has an extra ^13C at the C_γ of the ring. By taking advantage of the stereospecific deuteration of one of the prochiral β-methylene protons, which was ^1H_β2 in this experiment, one can determine the side-chain conformation of the Trp residue including the χ_2 angle, which is especially important for Trp residues, as they can adopt three preferred conformations. We demonstrated the usefulness of [^12C_γ,^12C_ε2] SAIL-Trp for the 12 kDa DNA binding domain of mouse c-Myb Protein (Myb-R2R3), which contains six Trp residues.
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alternative sail trp for robust aromatic signal assignment and determination of the χ 2 conformation by intra residue noes
Journal of Biomolecular NMR, 2011Co-Authors: Yohei Miyanoiri, Tsutomu Terauchi, Kosuke Okuma, Masatsune Kainosho, Mitsuhiro TakedaAbstract:Tryptophan (Trp) residues are frequently found in the hydrophobic cores of Proteins, and therefore, their side-chain conformations, especially the precise locations of the bulky indole rings, are critical for determining structures by NMR. However, when analyzing [U–13C,15N]-Proteins, the observation and assignment of the ring signals are often hampered by excessive overlaps and tight spin couplings. These difficulties have been greatly alleviated by using stereo-array isotope labeled (SAIL) Proteins, which are composed of isotope-labeled amino acids optimized for unambiguous side-chain NMR assignment, exclusively through the 13C–13C and 13C–1H spin coupling networks (Kainosho et al. in Nature 440:52–57, 2006). In this paper, we propose an alternative type of SAIL-Trp with the [ζ2,ζ3-2H2; δ1,e3,η2-13C3; e1-15N]-indole ring ([12C γ, 12 Ce2] SAIL-Trp), which provides a more robust way to correlate the 1Hβ, 1Hα, and 1HN to the 1Hδ1 and 1He3 through the intra-residue NOEs. The assignment of the 1Hδ1/13Cδ1 and 1He3/13Ce3 signals can thus be transferred to the 1He1/15Ne1 and 1Hη2/13Cη2 signals, as with the previous type of SAIL-Trp, which has an extra 13C at the Cγ of the ring. By taking advantage of the stereospecific deuteration of one of the prochiral β-methylene protons, which was 1Hβ2 in this experiment, one can determine the side-chain conformation of the Trp residue including the χ2 angle, which is especially important for Trp residues, as they can adopt three preferred conformations. We demonstrated the usefulness of [12Cγ,12Ce2] SAIL-Trp for the 12 kDa DNA binding domain of mouse c-Myb Protein (Myb-R2R3), which contains six Trp residues.
Kensuke Akaogi - One of the best experts on this subject based on the ideXlab platform.
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the nucleolar Protein Myb binding Protein 1a Mybbp1a enhances p53 tetramerization and acetylation in response to nucleolar disruption
Journal of Biological Chemistry, 2014Co-Authors: Wakana Ono, Kensuke Akaogi, Tsuyoshi Waku, Takao Kuroda, Wataru Yokoyama, Yuki Hayashi, Keiji Kimura, Hiroyuki Kishimoto, Ichiaki Ito, Junn YanagisawaAbstract:Tetramerization of p53 is crucial to exert its biological activity, and nucleolar disruption is sufficient to activate p53. We previously demonstrated that nucleolar stress induces translocation of the nucleolar Protein MybBP1A from the nucleolus to the nucleoplasm and enhances p53 activity. However, whether and how MybBP1A regulates p53 tetramerization in response to nucleolar stress remain unclear. In this study, we demonstrated that MybBP1A enhances p53 tetramerization, followed by acetylation under nucleolar stress. We found that MybBP1A has two regions that directly bind to lysine residues of the p53 C-terminal regulatory domain. MybBP1A formed a self-assembled complex that provided a molecular platform for p53 tetramerization and enhanced p300-mediated acetylation of the p53 tetramer. Moreover, our results show that MybBP1A functions to enhance p53 tetramerization that is necessary for p53 activation, followed by cell death with actinomycin D treatment. Thus, we suggest that MybBP1A plays a pivotal role in the cellular stress response.
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Nucleolar Protein, Myb-binding Protein 1A, specifically binds to nonacetylated p53 and efficiently promotes transcriptional activation.
Biochemical and biophysical research communications, 2013Co-Authors: Wakana Ono, Kensuke Akaogi, Tsuyoshi Waku, Takao Kuroda, Wataru Yokoyama, Yuki Hayashi, Keiji Kimura, Hiroyuki Kishimoto, Junn YanagisawaAbstract:Nucleolar dynamics are important for cellular stress response. We previously demonstrated that nucleolar stress induces nucleolar Protein Myb-binding Protein 1A (MybBP1A) translocation from the nucleolus to the nucleoplasm and enhances p53 activity. However, the underlying molecular mechanism is understood to a lesser extent. Here we demonstrate that MybBP1A interacts with lysine residues in the C-terminal regulatory domain region of p53. MybBP1A specifically interacts with nonacetylated p53 and induces p53 acetylation. We propose that MybBP1A dissociates from acetylated p53 because MybBP1A did not interact with acetylated p53 and because MybBP1A was not recruited to the p53 target promoter. Therefore, once p53 is acetylated, MybBP1A dissociates from p53 and interacts with nonacetylated p53, which enables another cycle of p53 activation. Based on our observations, this MybBP1A-p53 binding property can account for efficient p53-activation by MybBP1A under nucleolar stress. Our results support the idea that MybBP1A plays catalytic roles in p53 acetylation and activation.
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MybBP1A suppresses breast cancer tumorigenesis by enhancing the p53 dependent anoikis
BMC cancer, 2013Co-Authors: Kensuke Akaogi, Wakana Ono, Yuki Hayashi, Hiroyuki Kishimoto, Junn YanagisawaAbstract:Background Tumor suppressor p53 is mutated in a wide variety of human cancers and plays a critical role in anoikis, which is essential for preventing tumorigenesis. Recently, we found that a nucleolar Protein, Myb-binding Protein 1a (MybBP1A), was involved in p53 activation. However, the function of MybBP1A in cancer prevention has not been elucidated.
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MybBP1A suppresses breast cancer tumorigenesis by enhancing the p53 dependent anoikis
BMC Cancer, 2013Co-Authors: Kensuke Akaogi, Wakana Ono, Yuki Hayashi, Hiroyuki Kishimoto, Junn YanagisawaAbstract:Background Tumor suppressor p53 is mutated in a wide variety of human cancers and plays a critical role in anoikis, which is essential for preventing tumorigenesis. Recently, we found that a nucleolar Protein, Myb-binding Protein 1a (MybBP1A), was involved in p53 activation. However, the function of MybBP1A in cancer prevention has not been elucidated. Methods Relationships between MybBP1A expression levels and breast cancer progression were examined using patient microarray databases and tissue microarrays. Colony formation, xenograft, and anoikis assays were conducted using cells in which MybBP1A was either knocked down or overexpressed. p53 activation and interactions between p53 and MybBP1A were assessed by immunoprecipitation and western blot. Results MybBP1A expression was negatively correlated with breast cancer tumorigenesis. In vivo and in vitro experiments using the breast cancer cell lines MCF-7 and ZR-75-1, which expresses wild type p53, showed that tumorigenesis, colony formation, and anoikis resistance were significantly enhanced by MybBP1A knockdown. We also found that MybBP1A binds to p53 and enhances p53 target gene transcription under anoikis conditions. Conclusions These results suggest that MybBP1A is required for p53 activation during anoikis; therefore, it is involved in suppressing colony formation and the tumorigenesis of breast cancer cells. Collectively, our results suggest that MybBP1A plays a role in tumor prevention in the context of p53 activation.
