Background The bromodomain(BRD) proteins play a pivotal role in regulating gene expression by recognizing acetylated lysine residues and acting as chromatin-associated post-translational modification-inducing proteins...Background The bromodomain(BRD) proteins play a pivotal role in regulating gene expression by recognizing acetylated lysine residues and acting as chromatin-associated post-translational modification-inducing proteins. Although BRD proteins have been extensively studied in mammals, they have also been characterized in plants like Arabidopsis thaliana and Oryza sativa, where they regulate stress-responsive genes related to drought, salinity, and cold. However, their roles in cotton species remain unexplored.Results In this genome-wide comparative analysis, 145 BRD genes were identified in the tetraploid species(Gossypium hirsutum and G. barbadense), compared with 82 BRD genes in their diploid progenitors(G. arboreum and G. raimondii), indicating that polyploidization significantly influenced BRD gene evolution. Gene duplication analysis revealed 78.85% of duplications were segmental and 21.15% were tandem among 104 in-paralogous gene pairs, contributing to BRD gene expansion. Gene structure, motif, and domain analyses demonstrated that most genes were intron-less and conserved throughout evolution. Syntenic analysis revealed a greater number of orthologous gene pairs in the Dt sub-genome than in the At sub-genome. The abundance of regulatory, hormonal, and defense-related cis-regulatory elements in the promoter region suggests that BRD genes play a role in both biotic and abiotic stress responses. Protein-protein interaction analysis indicated that global transcription factor group E(GTE) transcription factors regulate BRD genes. Expression analysis revealed that BRD genes are predominantly involved in ovule development, with some genes displaying specific expression patterns under heat, cold, and salt stress. Furthermore, qRT-PCR analysis demonstrated significant differential expression of BRD genes between the tolerant and sensitive genotype, underscoring their potential role in mediating drought and salinity stress responses.Conclusions This study provides valuable insights into the evolution of BRD genes across species and their roles in abiotic stress tolerance, highlighting their potential in breeding programs to develop drought and salinity tolerant cotton varieties.展开更多
BACKGROUND:Hepatic ischemia-reperfusion(I/R)injury is a major challenge in liver surgery and transplantation.Bromodomain protein 4(BRD4)has emerged as a promising target due to its role in oxidative stress and inflamm...BACKGROUND:Hepatic ischemia-reperfusion(I/R)injury is a major challenge in liver surgery and transplantation.Bromodomain protein 4(BRD4)has emerged as a promising target due to its role in oxidative stress and inflammation.JQ-1,a specific BRD4 inhibitor,has shown protective effects on organs suffering I/R injury.This study aims to investigate the expression of BRD4 in liver tissues after I/R injury and to explore its role in this process using JQ-1 both in vivo and in vitro.METHODS:Our study established a mouse model of hepatic I/R injury and investigated the protective effect of JQ-1.We compared the histological features,BRD4 expression,and liver enzyme levels between JQ-1-treated and untreated groups.Additionally,the antioxidant properties of JQ-1 were analyzed in RAW 264.7 cells by evaluating cytokine expression,NLRP3 inflammasome activity,and reactive oxygen species production.RESULTS:BRD4 was abundantly expressed in liver tissues after hepatic I/R injury,while JQ-1 treatment had antioxidant and hepatoprotective effects.JQ-1 also suppressed pro-inflammatory cytokine release in vitro.Furthermore,we clarified the mechanism by which JQ-1 enhances liver injury recovery through Kupffer cells by blocking the NOD-like receptor thermal protein domain-associated protein 3(NLRP3)/caspase-1 pathway.CONCLUSION:JQ-1 has potential as a pre-clinical emergency therapy for hepatic I/R injury.Its ability to inhibit BRD4 and modulate the inflammatory response in Kupffer cells offers a promising avenue for future clinical intervention.展开更多
Gastrointestinal(GI)cancers,including colorectal cancer,pancreatic cancer,liver cancer and gastric cancer,are severe social burdens due to high incidence and mortality rates.Bromodomain and extra-terminal(BET)proteins...Gastrointestinal(GI)cancers,including colorectal cancer,pancreatic cancer,liver cancer and gastric cancer,are severe social burdens due to high incidence and mortality rates.Bromodomain and extra-terminal(BET)proteins are epigenetic readers consisting of four conserved members(BRD2,BRD3,BRD4 and BRDT).BET family perform pivotal roles in tumorigenesis through transcriptional regulation,thereby emerging as potential therapeutic targets.BET inhibitors,disrupting the interaction between BET proteins and acetylated lysines,have been reported to suppress tumor initiation and progression in most of GI cancers.In this review,we will demonstrate how BET proteins participate in the GI cancers progression and highlight the therapeutic potential of targeting BET proteins for GI cancers treatment.展开更多
组蛋白赖氨酸乙酰化的识别是组蛋白乙酰化参与表观遗传调控的关键步骤,乙酰化的组蛋白赖氨酸可以被bromodomains(BRDs)结构域所特异性的识别,从而招募染色质调控因子到特定区域,协同完成基因表达调控。其中作用于bromodomain and extra-...组蛋白赖氨酸乙酰化的识别是组蛋白乙酰化参与表观遗传调控的关键步骤,乙酰化的组蛋白赖氨酸可以被bromodomains(BRDs)结构域所特异性的识别,从而招募染色质调控因子到特定区域,协同完成基因表达调控。其中作用于bromodomain and extra-terminal(BET)蛋白家族的BRD结构域的小分子抑制剂在抗炎和抗肿瘤方面显示出巨大的潜力。本文通过对与BET bromodomain靶点相关的疾病、BET bromodomain结构、BET bromodomain小分子抑制剂的化学结构分类及其构效关系等多方面进行总结,为设计和开发高活性的BET bromodomain小分子抑制剂提供参考依据。展开更多
BACKGROUND The overexpression of the MYC gene plays an important role in the occurrence,development and evolution of colorectal cancer(CRC).Bromodomain and extraterminal domain(BET)inhibitors can decrease the function...BACKGROUND The overexpression of the MYC gene plays an important role in the occurrence,development and evolution of colorectal cancer(CRC).Bromodomain and extraterminal domain(BET)inhibitors can decrease the function BET by recognizing acetylated lysine residues,thereby downregulating the expression of MYC.AIM To investigate the inhibitory effect and mechanism of a BET inhibitor on CRC cells.METHODS The effect of the BET inhibitor JAB-8263 on the proliferation of various CRC cell lines was studied by CellTiter-Glo method and colony formation assay.The effect of JAB-8263 on the cell cycle and apoptosis of CRC cells was studied by propidium iodide staining and Annexin V/propidium iodide flow assay,respectively.The effect of JAB-8263 on the expression of c-MYC,p21 and p16 in CRC cells was detected by western blotting assay.The anti-tumor effect of JAB-8263 on CRC cells in vivo and evaluation of the safety of the compound was predicted by constructing a CRC cell animal tumor model.RESULTS JAB-8263 dose-dependently suppressed CRC cell proliferation and colony formation in vitro.The MYC signaling pathway was dose-dependently inhibited by JAB-8263 in human CRC cell lines.JAB-8263 dose-dependently induced cell cycle arrest and apoptosis in the MC38 cell line.SW837 xenograft model was treated with JAB-8263(0.3 mg/kg for 29 d),and the average tumor volume was significantly decreased compared to the vehicle control group(P<0.001).The MC38 syngeneic murine model was treated with JAB-8263(0.2 mg/kg for 29 d),and the average tumor volume was significantly decreased compared to the vehicle control group(P=0.003).CONCLUSION BET could be a potential effective drug target for suppressing CRC growth,and the BET inhibitor JAB-8263 can effectively suppress c-MYC expression and exert anti-tumor activity in CRC models.展开更多
The Polybromo （PB） protein functions as a key component of the human PBAF chromatin remodeling complex in regulation of gene transcription. PB is made up of modular domains including six bromodomains that are known ...The Polybromo （PB） protein functions as a key component of the human PBAF chromatin remodeling complex in regulation of gene transcription. PB is made up of modular domains including six bromodomains that are known as acetyl-lysine binding domains. However, histone-binding specificity of the bromodomains of PB has remained elusive. In this study, we report biochemical characterization of all six PB bromodomains＇ binding to a suite of lysine-acetylated peptides derived from known acetylation sites on human core histones. We demonstrate that bromodomain 2 of PB preferentially recognizes acetylated lysine 14 of histone H3 （H3K14ac）, a post-translational mark known for gene transcriptional activation. We further describe the molecular basis of the selective H3K14ac recognition of bromodomain 2 by solving the protein structures in both the free and bound forms using X-ray crystallography and NMR, respectively.展开更多
FgGCN5,a GCN5 homolog in Fusarium graminearum,plays a critical role in hyphal vegetative growth,asexual and sexual reproduction,deoxynivalenol(DON)biosynthesis and plant infection.For nuclear localized GCN5,four conse...FgGCN5,a GCN5 homolog in Fusarium graminearum,plays a critical role in hyphal vegetative growth,asexual and sexual reproduction,deoxynivalenol(DON)biosynthesis and plant infection.For nuclear localized GCN5,four conserved sequence motifs(I-IV)are presented in the catalytic domain and a bromodomain in the carboxy-terminus.As a lysine acetyltransferase,conserved negatively charged residues are present to neutralize the protons from lysine substrates.However,the role of conserved motifs/domains and residues in FgGCN5 are unclear.Here,we generated deletion mutant strains for each the conserved motifs/domains and a glutamate residue 130(E130)replacement mutant.Deletion of each conserved motif in the catalytic domain and replacement of E130 site resulted in manifold defects in hyphae growth,asexual and sexual development,DON biosynthesis,and plant infection.Phenotypic defects in the mutant strains were similar to deletion mutants.The deletion of the bromodomain led a significant reduction in DON production and virulence,with no effects on hyphae growth,asexual or sexual reproduction.FgGCN5 was further found to localize to the nucleus in conidia and hyphae cells.In conclusion,FgGCN5 encodes a nuclear localized acetyltransferase.The conserved motifs in the catalytic domain and E130 are essential for correct functions of the gene.The conserved bromodomain is impotant for DON production and pathogen virulence.This was the first report to identify the functions of conserved motifs/domains in FgGCN5,which will contribute to our understanding of the mechanism(s)by which FgGCN5 regulates F.graminearum.展开更多
OBJECTIVE To discover a small-molecule bromodomain-containing protein 4(BRD4)inhibitor that induces AMP-activated protein kinase-modulated autophagy-associated cell death in breast cancer and exploreits potential mech...OBJECTIVE To discover a small-molecule bromodomain-containing protein 4(BRD4)inhibitor that induces AMP-activated protein kinase-modulated autophagy-associated cell death in breast cancer and exploreits potential mechanisms.METHODS BRD4 interactors were analyzed by PPI network prediction and The Cancer Genome Atlas(TCGA)analysis.The interaction between BRD4 and AMPK was confirmed by co-immunoprecipitation assay.Novel BRD4 inhibitors were designed and synthesized based upon pharmacophore analysis of BRD4(1),then screened by antiproliferative activity and Alpha Screen of BRD4(1).The selectivity of the best candidate compound 8f was validated by co-crystallization,FRET assay and co-immuno precipitation assay.The mechanisms of 8f were investigated by fluorescence microscopy,electron microscopy,Western blotting,immunocytochemistry,si RNA and GFP-m RFP-LC3 plasmid transfections,as well as immunohistochemistry and immunofluorescence.Potential mechanisms were discovered by i TRAQ-based proteomics analysis and the therapeutic effect of 8f was assessed by xenograft breast cancer mouse and zebrafish models.RESULTS We identified that BRD4 interacted with AMPK,which was remarkably downregulated in breast cancer.We next designed and synthesized 49 candidate compounds,and eventually discovered a selective small-molecule inhibitor of BRD4(8f).Subsequently,8f was discovered to induce autophagyassociated cell death(ACD)by BRD4-AMPK interaction,and thus activating AMPK-m TOR-ULK1-modulated autophagic pathway in breast cancer cells.Interestingly,the i TRAQ-based proteomics analyses revealed that 8f induced ACD pathways,involved in HMGB1,VDAC1/2 and e EF2.Moreover,8f displayed a therapeutic potential on both xenograft breast cancer mouse and zebrafish models.CONCLUSION We discovered a novel small-molecule inhibitor of BRD4 that induces BRD4-AMPK-modulated ACD in breast cancer,which may provide a candidate drug for future cancer therapy.展开更多
Lysine acetylation is one of the most prevalent and important posttranslational modifications(PTMs) in proteins. The process can be recognized by bromodomains(BRDs), which are a class of proteininteraction modules inv...Lysine acetylation is one of the most prevalent and important posttranslational modifications(PTMs) in proteins. The process can be recognized by bromodomains(BRDs), which are a class of proteininteraction modules involved in chromatin remodeling and transcriptional activation. The development of BRD fluorescent probes will be useful for monitoring the activity of BRDs in living cells as well as aiding inhibitor development. Herein we designed a peptide-based probe based on the proximity-induced protein conjugation reaction. The peptide-based probe is capable of covalently and selectively reacting with the unique cysteine residue in the bromodomain through proximity effect. Our experimental data showed that the probe displayed noticeable fluorescence response upon addition of BRD4(1). In-gel fluorescence scanning demonstrated that BRD4(1) can be covalently labelled by the probe. Moreover, the probe was shown to selectively detect BRD4(1) over other proteins. We envision that the probe developed in this study will provide a useful tool to further investigate the biological roles of BRDs.展开更多
文摘Background The bromodomain(BRD) proteins play a pivotal role in regulating gene expression by recognizing acetylated lysine residues and acting as chromatin-associated post-translational modification-inducing proteins. Although BRD proteins have been extensively studied in mammals, they have also been characterized in plants like Arabidopsis thaliana and Oryza sativa, where they regulate stress-responsive genes related to drought, salinity, and cold. However, their roles in cotton species remain unexplored.Results In this genome-wide comparative analysis, 145 BRD genes were identified in the tetraploid species(Gossypium hirsutum and G. barbadense), compared with 82 BRD genes in their diploid progenitors(G. arboreum and G. raimondii), indicating that polyploidization significantly influenced BRD gene evolution. Gene duplication analysis revealed 78.85% of duplications were segmental and 21.15% were tandem among 104 in-paralogous gene pairs, contributing to BRD gene expansion. Gene structure, motif, and domain analyses demonstrated that most genes were intron-less and conserved throughout evolution. Syntenic analysis revealed a greater number of orthologous gene pairs in the Dt sub-genome than in the At sub-genome. The abundance of regulatory, hormonal, and defense-related cis-regulatory elements in the promoter region suggests that BRD genes play a role in both biotic and abiotic stress responses. Protein-protein interaction analysis indicated that global transcription factor group E(GTE) transcription factors regulate BRD genes. Expression analysis revealed that BRD genes are predominantly involved in ovule development, with some genes displaying specific expression patterns under heat, cold, and salt stress. Furthermore, qRT-PCR analysis demonstrated significant differential expression of BRD genes between the tolerant and sensitive genotype, underscoring their potential role in mediating drought and salinity stress responses.Conclusions This study provides valuable insights into the evolution of BRD genes across species and their roles in abiotic stress tolerance, highlighting their potential in breeding programs to develop drought and salinity tolerant cotton varieties.
文摘BACKGROUND:Hepatic ischemia-reperfusion(I/R)injury is a major challenge in liver surgery and transplantation.Bromodomain protein 4(BRD4)has emerged as a promising target due to its role in oxidative stress and inflammation.JQ-1,a specific BRD4 inhibitor,has shown protective effects on organs suffering I/R injury.This study aims to investigate the expression of BRD4 in liver tissues after I/R injury and to explore its role in this process using JQ-1 both in vivo and in vitro.METHODS:Our study established a mouse model of hepatic I/R injury and investigated the protective effect of JQ-1.We compared the histological features,BRD4 expression,and liver enzyme levels between JQ-1-treated and untreated groups.Additionally,the antioxidant properties of JQ-1 were analyzed in RAW 264.7 cells by evaluating cytokine expression,NLRP3 inflammasome activity,and reactive oxygen species production.RESULTS:BRD4 was abundantly expressed in liver tissues after hepatic I/R injury,while JQ-1 treatment had antioxidant and hepatoprotective effects.JQ-1 also suppressed pro-inflammatory cytokine release in vitro.Furthermore,we clarified the mechanism by which JQ-1 enhances liver injury recovery through Kupffer cells by blocking the NOD-like receptor thermal protein domain-associated protein 3(NLRP3)/caspase-1 pathway.CONCLUSION:JQ-1 has potential as a pre-clinical emergency therapy for hepatic I/R injury.Its ability to inhibit BRD4 and modulate the inflammatory response in Kupffer cells offers a promising avenue for future clinical intervention.
基金Fellowship of the China Postdoctoral Science Foundation,No.2020M682594,and No.2021T140748.
文摘Gastrointestinal(GI)cancers,including colorectal cancer,pancreatic cancer,liver cancer and gastric cancer,are severe social burdens due to high incidence and mortality rates.Bromodomain and extra-terminal(BET)proteins are epigenetic readers consisting of four conserved members(BRD2,BRD3,BRD4 and BRDT).BET family perform pivotal roles in tumorigenesis through transcriptional regulation,thereby emerging as potential therapeutic targets.BET inhibitors,disrupting the interaction between BET proteins and acetylated lysines,have been reported to suppress tumor initiation and progression in most of GI cancers.In this review,we will demonstrate how BET proteins participate in the GI cancers progression and highlight the therapeutic potential of targeting BET proteins for GI cancers treatment.
基金Supported by the National Natural Science Foundation of China,No.81871317.
文摘BACKGROUND The overexpression of the MYC gene plays an important role in the occurrence,development and evolution of colorectal cancer(CRC).Bromodomain and extraterminal domain(BET)inhibitors can decrease the function BET by recognizing acetylated lysine residues,thereby downregulating the expression of MYC.AIM To investigate the inhibitory effect and mechanism of a BET inhibitor on CRC cells.METHODS The effect of the BET inhibitor JAB-8263 on the proliferation of various CRC cell lines was studied by CellTiter-Glo method and colony formation assay.The effect of JAB-8263 on the cell cycle and apoptosis of CRC cells was studied by propidium iodide staining and Annexin V/propidium iodide flow assay,respectively.The effect of JAB-8263 on the expression of c-MYC,p21 and p16 in CRC cells was detected by western blotting assay.The anti-tumor effect of JAB-8263 on CRC cells in vivo and evaluation of the safety of the compound was predicted by constructing a CRC cell animal tumor model.RESULTS JAB-8263 dose-dependently suppressed CRC cell proliferation and colony formation in vitro.The MYC signaling pathway was dose-dependently inhibited by JAB-8263 in human CRC cell lines.JAB-8263 dose-dependently induced cell cycle arrest and apoptosis in the MC38 cell line.SW837 xenograft model was treated with JAB-8263(0.3 mg/kg for 29 d),and the average tumor volume was significantly decreased compared to the vehicle control group(P<0.001).The MC38 syngeneic murine model was treated with JAB-8263(0.2 mg/kg for 29 d),and the average tumor volume was significantly decreased compared to the vehicle control group(P=0.003).CONCLUSION BET could be a potential effective drug target for suppressing CRC growth,and the BET inhibitor JAB-8263 can effectively suppress c-MYC expression and exert anti-tumor activity in CRC models.
文摘The Polybromo （PB） protein functions as a key component of the human PBAF chromatin remodeling complex in regulation of gene transcription. PB is made up of modular domains including six bromodomains that are known as acetyl-lysine binding domains. However, histone-binding specificity of the bromodomains of PB has remained elusive. In this study, we report biochemical characterization of all six PB bromodomains＇ binding to a suite of lysine-acetylated peptides derived from known acetylation sites on human core histones. We demonstrate that bromodomain 2 of PB preferentially recognizes acetylated lysine 14 of histone H3 （H3K14ac）, a post-translational mark known for gene transcriptional activation. We further describe the molecular basis of the selective H3K14ac recognition of bromodomain 2 by solving the protein structures in both the free and bound forms using X-ray crystallography and NMR, respectively.
基金Supported by the open project of the State Key Laboratory of Crop Stress Biology for Arid Areas,Northwest A&F University,China(CSBAA2016001).
文摘FgGCN5,a GCN5 homolog in Fusarium graminearum,plays a critical role in hyphal vegetative growth,asexual and sexual reproduction,deoxynivalenol(DON)biosynthesis and plant infection.For nuclear localized GCN5,four conserved sequence motifs(I-IV)are presented in the catalytic domain and a bromodomain in the carboxy-terminus.As a lysine acetyltransferase,conserved negatively charged residues are present to neutralize the protons from lysine substrates.However,the role of conserved motifs/domains and residues in FgGCN5 are unclear.Here,we generated deletion mutant strains for each the conserved motifs/domains and a glutamate residue 130(E130)replacement mutant.Deletion of each conserved motif in the catalytic domain and replacement of E130 site resulted in manifold defects in hyphae growth,asexual and sexual development,DON biosynthesis,and plant infection.Phenotypic defects in the mutant strains were similar to deletion mutants.The deletion of the bromodomain led a significant reduction in DON production and virulence,with no effects on hyphae growth,asexual or sexual reproduction.FgGCN5 was further found to localize to the nucleus in conidia and hyphae cells.In conclusion,FgGCN5 encodes a nuclear localized acetyltransferase.The conserved motifs in the catalytic domain and E130 are essential for correct functions of the gene.The conserved bromodomain is impotant for DON production and pathogen virulence.This was the first report to identify the functions of conserved motifs/domains in FgGCN5,which will contribute to our understanding of the mechanism(s)by which FgGCN5 regulates F.graminearum.
基金supported by National Natural Science Foundation of China(81473091,81673290 and U1603123)
文摘OBJECTIVE To discover a small-molecule bromodomain-containing protein 4(BRD4)inhibitor that induces AMP-activated protein kinase-modulated autophagy-associated cell death in breast cancer and exploreits potential mechanisms.METHODS BRD4 interactors were analyzed by PPI network prediction and The Cancer Genome Atlas(TCGA)analysis.The interaction between BRD4 and AMPK was confirmed by co-immunoprecipitation assay.Novel BRD4 inhibitors were designed and synthesized based upon pharmacophore analysis of BRD4(1),then screened by antiproliferative activity and Alpha Screen of BRD4(1).The selectivity of the best candidate compound 8f was validated by co-crystallization,FRET assay and co-immuno precipitation assay.The mechanisms of 8f were investigated by fluorescence microscopy,electron microscopy,Western blotting,immunocytochemistry,si RNA and GFP-m RFP-LC3 plasmid transfections,as well as immunohistochemistry and immunofluorescence.Potential mechanisms were discovered by i TRAQ-based proteomics analysis and the therapeutic effect of 8f was assessed by xenograft breast cancer mouse and zebrafish models.RESULTS We identified that BRD4 interacted with AMPK,which was remarkably downregulated in breast cancer.We next designed and synthesized 49 candidate compounds,and eventually discovered a selective small-molecule inhibitor of BRD4(8f).Subsequently,8f was discovered to induce autophagyassociated cell death(ACD)by BRD4-AMPK interaction,and thus activating AMPK-m TOR-ULK1-modulated autophagic pathway in breast cancer cells.Interestingly,the i TRAQ-based proteomics analyses revealed that 8f induced ACD pathways,involved in HMGB1,VDAC1/2 and e EF2.Moreover,8f displayed a therapeutic potential on both xenograft breast cancer mouse and zebrafish models.CONCLUSION We discovered a novel small-molecule inhibitor of BRD4 that induces BRD4-AMPK-modulated ACD in breast cancer,which may provide a candidate drug for future cancer therapy.
基金the financial support from the National Natural Science Foundation of China (No. 21572190)the Hong Kong Early Career Scheme Grant (No. 21300714)the City University of Hong Kong Grant (No. 9667147)
文摘Lysine acetylation is one of the most prevalent and important posttranslational modifications(PTMs) in proteins. The process can be recognized by bromodomains(BRDs), which are a class of proteininteraction modules involved in chromatin remodeling and transcriptional activation. The development of BRD fluorescent probes will be useful for monitoring the activity of BRDs in living cells as well as aiding inhibitor development. Herein we designed a peptide-based probe based on the proximity-induced protein conjugation reaction. The peptide-based probe is capable of covalently and selectively reacting with the unique cysteine residue in the bromodomain through proximity effect. Our experimental data showed that the probe displayed noticeable fluorescence response upon addition of BRD4(1). In-gel fluorescence scanning demonstrated that BRD4(1) can be covalently labelled by the probe. Moreover, the probe was shown to selectively detect BRD4(1) over other proteins. We envision that the probe developed in this study will provide a useful tool to further investigate the biological roles of BRDs.
