BACKGROUND Post-translational modifications play key roles in various biological processes.Protein arginine methyltransferases(PRMTs)transfer the methyl group to specific arginine residues.Both PRMT1 and PRMT6 have em...BACKGROUND Post-translational modifications play key roles in various biological processes.Protein arginine methyltransferases(PRMTs)transfer the methyl group to specific arginine residues.Both PRMT1 and PRMT6 have emerges as crucial factors in the development and progression of multiple cancer types.We posit that PRMT1 and PRMT6 might interplay directly or in-directly in multiple ways accounting for shared disease phenotypes.AIM To investigate the mechanism of the interaction between PRMT1 and PRMT6.METHODS Gel electrophoresis autoradiography was performed to test the methyltranferase activity of PRMTs and characterize the kinetics parameters of PRMTs.Liquid chromatography-tandem mass spectrometryanalysis was performed to detect the PRMT6 methylation sites.RESULTS In this study we investigated the interaction between PRMT1 and PRMT6,and PRMT6 was shown to be a novel substrate of PRMT1.We identified specific arginine residues of PRMT6 that are methylated by PRMT1,with R106 being the major methylation site.Combined biochemical and cellular data showed that PRMT1 downregulates the enzymatic activity of PRMT6 in histone H3 methylation.CONCLUSION PRMT6 is methylated by PRMT1 and R106 is a major methylation site induced by PRMT1.PRMT1 methylation suppresses the activity of PRMT6.展开更多
Objective To screen the asymmetric dimethyl arginines (ADMA)-containing proteins which could combine with protein arginine methyltransferase 1 (PRMT1). Methods Western blot was adopted to identify the expression of PR...Objective To screen the asymmetric dimethyl arginines (ADMA)-containing proteins which could combine with protein arginine methyltransferase 1 (PRMT1). Methods Western blot was adopted to identify the expression of PRMT1 and the proteins with ADMA in glioma cell lines and normal brain tissues, and then to detect the changes of ADMA level after knock-down of PRMT1 with RNAi transfection in U87MG cells. Co-Immunoprecipitation (Co-IP), western blot, and sliver staining were employed to screen the candidate binding proteins of PRMT1. Then liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to identify the binding proteins of PRMT1. Results The expression of PRMT1 and some levels of ADMA were higher in glioma cell lines than in normal brain tissues. After knocking down PRMT1, some ADMA levels were found declined. After screening the binding proteins of PRMT1 with Co-IP and LC-MS/MS, 26 candidate binding proteins were identified. Among them, 6 candidate proteins had higher ions scores (>38) and bioinformation analysis predicted that SEC23-IP, ANKHD1-EIF4EBP3 protein, and 1-phosphatidylinositol-3-phosphate 5-kinase isoform 2 had possible methylated aginine sites. Conclusions The high expression of PRMT1 in glioma may induce the change of ADMA levels. Altogether 26 candidate proteins were identified, which contain ADMA and specifically bind with PRMT1.展开更多
Protein arginine methylation is a common post-translational modification involved in the regulation of various cellular functions. Coactivator-associated arginine methyltransferase 1 (CARM1) is a protein arginine meth...Protein arginine methylation is a common post-translational modification involved in the regulation of various cellular functions. Coactivator-associated arginine methyltransferase 1 (CARM1) is a protein arginine methyltransferase that asymmetrically dimethylates histone H3 and non-histone proteins to regulate gene transcription. CARM1 has been found to play important roles in cell differentiation and development, cell cycle progression, autophagy, metabolism, pre-mRNA splicing and transportation, and DNA replication. In this review, we describe the molecular characteristics of CARM1 and summarize its roles in the regulation of cell differentiation and development in mammals.展开更多
Arabidopsis AtPRMT10 is a plant-specific type I protein arginine methyltransferase that can asymmetrically dimethylate arginine 3 of histone H4 with auto-methylation activity.Mutations of AtPRMT10 derepress FLOWERING ...Arabidopsis AtPRMT10 is a plant-specific type I protein arginine methyltransferase that can asymmetrically dimethylate arginine 3 of histone H4 with auto-methylation activity.Mutations of AtPRMT10 derepress FLOWERING LOCUS C(FLC)expression resulting in a late-flowering phenotype.Here,to further investigate the biochemical characteristics of AtPRMT10,we analyzed a series of mutated forms of the AtPRMT10 protein.We demon-strate that the conserved“VLD”residues and“double-E loop”are essential for enzymatic activity of AtPRMT10.In addition,we show that Arg54 and Cys259 of AtPRMT10,two residues unreported in animals,are also important for its enzymatic activity.We find that Arg13 of AtPRMT10 is the auto-methylation site.However,substitution of Arg13 to Lys13 does not affect its enzymatic activity.In vivo complementation assays reveal that plants expressing AtPRMT10 with VLD-AAA,E143Q or E152Q mutations retain high levels of FLC expression and fail to rescue the late-flowering phenotype of atprmt10 plants.Taken together,we conclude that the methyltransferase activity of AtPRMT10 is essential for repressing FLC expression and promoting flowering in Arabidopsis.展开更多
BACKGROUND Immunotherapy targeting programmed death-1(PD-1)or programmed deathligand-1(PD-L1)has been shown to be effective in a variety of malignancies but has poor efficacy in pancreatic ductal adenocarcinoma(PDAC)....BACKGROUND Immunotherapy targeting programmed death-1(PD-1)or programmed deathligand-1(PD-L1)has been shown to be effective in a variety of malignancies but has poor efficacy in pancreatic ductal adenocarcinoma(PDAC).Studies have shown that PD-L1 expression in tumors is an important indicator of the efficacy of immunotherapy.Tumor cells usually evade chemotherapy and host immune surveillance by epigenetic changes.Protein arginine methylation is a common posttranslational modification.Protein arginine methyltransferase(PRMT)1 is deregulated in a wide variety of cancer types,whose biological role in tumor immunity is undefined.AIM To investigate the combined effects and underlying mechanisms of anti-PD-L1 and type I PRMT inhibitor in pancreatic cancer in vivo.METHODS PT1001B is a novel type I PRMT inhibitor with strong activity and good selectivity.A mouse model of subcutaneous Panc02-derived tumors was used to evaluate drug efficacy,toxic and side effects,and tumor growth in vivo.By flow cytometry,we determined the expression of key immune checkpoint proteins,detected the apoptosis in tumor tissues,and analyzed the immune cells.Immunohistochemistry staining for cellular proliferation-associated nuclear protein Ki67,TUNEL assay,and PRMT1/PD-L1 immunofluorescence were used to elucidate the underlying molecular mechanism of the antitumor effect.RESULTS Cultured Panc02 cells did not express PD-L1 in vitro,but tumor cells derived from Panc02 transplanted tumors expressed PD-L1.The therapeutic efficacy of anti-PD-L1 mAb was significantly enhanced by the addition of PT1001B as measured by tumor volume(1054.00±61.37 mm3 vs 555.80±74.42 mm3,P<0.01)and tumor weight(0.83±0.06 g vs 0.38±0.02 g,P<0.05).PT1001B improved antitumor immunity by inhibiting PD-L1 expression on tumor cells(32.74%±5.89%vs 17.95%±1.92%,P<0.05).The combination therapy upregulated tumorinfiltrating CD8+T lymphocytes(23.75%±3.20%vs 73.34%±4.35%,P<0.01)and decreased PD-1+leukocytes(35.77%±3.30%vs 6.48%±1.08%,P<0.001)in tumor tissue compared to the control.In addition,PT1001B amplified the inhibitory effect of anti-PD-L1 on tumor cell proliferation and enhanced the induction of tumor cell apoptosis.PRMT1 downregulation was correlated with PD-L1 downregulation.CONCLUSION PT1001B enhances antitumor immunity and combining it with anti-PD-L1 checkpoint inhibitors provides a potential strategy to overcome anti-PD-L1 resistance in PDAC.展开更多
目的 探讨外周血单核细胞DNA甲基化转移酶1(DNMT1)及血清白介素-6(IL-6)在糖尿病肾脏病(DKD)中的表达及临床意义。方法 选取150例DKD患者(DKD组)及50例同期健康体检者(对照组)。比较2组IL-6、DNMT1、总胆固醇、三酰甘油、高密度脂蛋白...目的 探讨外周血单核细胞DNA甲基化转移酶1(DNMT1)及血清白介素-6(IL-6)在糖尿病肾脏病(DKD)中的表达及临床意义。方法 选取150例DKD患者(DKD组)及50例同期健康体检者(对照组)。比较2组IL-6、DNMT1、总胆固醇、三酰甘油、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)、血肌酐、空腹血糖、肾小球滤过率估计值(e GFR)、24 h尿白蛋白排泄率(24 h UAER)的差异。Pearson相关分析IL-6、DNMT1与其他临床指标的相关性。多因素Logistic回归分析DKD发生的影响因素。受试者工作特征(ROC)曲线分析24 h UAER、IL-6、DNMT1及联合检测对DKD的诊断价值。结果 与对照组比较,DKD组的空腹血糖、IL-6、DNMT1、血肌酐、24 h UAER、LDL-C、糖化血红蛋白水平升高,而eGFR、HDL-C水平降低(均P<0.05)。DKD组的IL-6与DNMT1呈正相关(r=0.560,P<0.05);且IL-6、DNMT1与24 h UAER呈正相关(r分别为0.551和0.570,P<0.05)。24 h UAER、IL-6及DNMT1升高是影响DKD发生的独立危险因素(P<0.05)。24 h UAER、IL-6、DNMT1联合检测诊断DKD的曲线下面积优于单一指标检测。结论 DKD患者DNMT1、IL-6水平升高,24 h UAER、DNMT1、IL-6联合检测可作为临床诊断DKD的良好指标。展开更多
AIM:To explore the relationship between DNA methyltransferase 1 (DNMT1) and hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) and its biological significance in primary HCC.METHODS: We carried out an immu...AIM:To explore the relationship between DNA methyltransferase 1 (DNMT1) and hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) and its biological significance in primary HCC.METHODS: We carried out an immunohistochemical examination of DNMT1 in both HCC and paired non-neoplastic liver tissues from Chinese subjects. DNMT1 mRNA was further examined in HCC cell lines by real-time PCR. We inhibited DNMT1 using siRNA and detected the effect of depletion of DNMT1 on cell proliferation ability and cell apoptosis in the HCC cell line SMMC-7721.RESULTS: DNMT1 protein expression was increased in HCCs compared to histologically normal non-neoplastic liver tissues and the incidence of DNMT1 immunoreactivity in HCCs correlated signifi cantly with poor tumor differentiation (P=0.014). There were more cases with DNMT1 overexpression in HCC with HBV (42.85%) than in HCC without HBV (28.57%). However, no signif icant difference in DNMT1 expression was found in HBV-positive and HBV-negative cases in the Chinese HCC group. There was a trend that DNMT1 RNA expression increased more in HCC cell lines than in pericarcinoma cell lines and normal liver cell lines. In addition, we inhibited DNMT1 using siRNA in the SMMC-7721 HCC cell line and found depletion of DNMT1 suppressed cells growth independent of expression of proliferating cell nuclear antigen (PCNA), even in HCC cell lines where DNMT1 was stably decreased.CONCLUSION: The f indings implied that DNMT1 plays a key role in HBV-related hepatocellular tumorigenesis. Depletion of DNMT1 mediates growth suppression in SMMC-7721 cells.展开更多
基金Supported by National Institutes of Health,No.5R01GM126154 and No.1R35GM149230。
文摘BACKGROUND Post-translational modifications play key roles in various biological processes.Protein arginine methyltransferases(PRMTs)transfer the methyl group to specific arginine residues.Both PRMT1 and PRMT6 have emerges as crucial factors in the development and progression of multiple cancer types.We posit that PRMT1 and PRMT6 might interplay directly or in-directly in multiple ways accounting for shared disease phenotypes.AIM To investigate the mechanism of the interaction between PRMT1 and PRMT6.METHODS Gel electrophoresis autoradiography was performed to test the methyltranferase activity of PRMTs and characterize the kinetics parameters of PRMTs.Liquid chromatography-tandem mass spectrometryanalysis was performed to detect the PRMT6 methylation sites.RESULTS In this study we investigated the interaction between PRMT1 and PRMT6,and PRMT6 was shown to be a novel substrate of PRMT1.We identified specific arginine residues of PRMT6 that are methylated by PRMT1,with R106 being the major methylation site.Combined biochemical and cellular data showed that PRMT1 downregulates the enzymatic activity of PRMT6 in histone H3 methylation.CONCLUSION PRMT6 is methylated by PRMT1 and R106 is a major methylation site induced by PRMT1.PRMT1 methylation suppresses the activity of PRMT6.
基金Supported by National Natural Science Foundation of China(30825023)
文摘Objective To screen the asymmetric dimethyl arginines (ADMA)-containing proteins which could combine with protein arginine methyltransferase 1 (PRMT1). Methods Western blot was adopted to identify the expression of PRMT1 and the proteins with ADMA in glioma cell lines and normal brain tissues, and then to detect the changes of ADMA level after knock-down of PRMT1 with RNAi transfection in U87MG cells. Co-Immunoprecipitation (Co-IP), western blot, and sliver staining were employed to screen the candidate binding proteins of PRMT1. Then liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to identify the binding proteins of PRMT1. Results The expression of PRMT1 and some levels of ADMA were higher in glioma cell lines than in normal brain tissues. After knocking down PRMT1, some ADMA levels were found declined. After screening the binding proteins of PRMT1 with Co-IP and LC-MS/MS, 26 candidate binding proteins were identified. Among them, 6 candidate proteins had higher ions scores (>38) and bioinformation analysis predicted that SEC23-IP, ANKHD1-EIF4EBP3 protein, and 1-phosphatidylinositol-3-phosphate 5-kinase isoform 2 had possible methylated aginine sites. Conclusions The high expression of PRMT1 in glioma may induce the change of ADMA levels. Altogether 26 candidate proteins were identified, which contain ADMA and specifically bind with PRMT1.
基金supported by Funding for Top-notch Personnel from Shandong First Medical University and Taishan Scholars Program(No.ts 2019097).
文摘Protein arginine methylation is a common post-translational modification involved in the regulation of various cellular functions. Coactivator-associated arginine methyltransferase 1 (CARM1) is a protein arginine methyltransferase that asymmetrically dimethylates histone H3 and non-histone proteins to regulate gene transcription. CARM1 has been found to play important roles in cell differentiation and development, cell cycle progression, autophagy, metabolism, pre-mRNA splicing and transportation, and DNA replication. In this review, we describe the molecular characteristics of CARM1 and summarize its roles in the regulation of cell differentiation and development in mammals.
基金supported by the National Basic Research Program of China(Nos.2011CB915400 and 2009CB941500 to X.C.)the National Natural Science Foundation of China(Grant Nos.30930048 and 30921061 to X.C.,and 90919033 to C.L.)the Chinese Academy of Sciences(No.KSCX2-EW-Q-24-02 to C.L.)。
文摘Arabidopsis AtPRMT10 is a plant-specific type I protein arginine methyltransferase that can asymmetrically dimethylate arginine 3 of histone H4 with auto-methylation activity.Mutations of AtPRMT10 derepress FLOWERING LOCUS C(FLC)expression resulting in a late-flowering phenotype.Here,to further investigate the biochemical characteristics of AtPRMT10,we analyzed a series of mutated forms of the AtPRMT10 protein.We demon-strate that the conserved“VLD”residues and“double-E loop”are essential for enzymatic activity of AtPRMT10.In addition,we show that Arg54 and Cys259 of AtPRMT10,two residues unreported in animals,are also important for its enzymatic activity.We find that Arg13 of AtPRMT10 is the auto-methylation site.However,substitution of Arg13 to Lys13 does not affect its enzymatic activity.In vivo complementation assays reveal that plants expressing AtPRMT10 with VLD-AAA,E143Q or E152Q mutations retain high levels of FLC expression and fail to rescue the late-flowering phenotype of atprmt10 plants.Taken together,we conclude that the methyltransferase activity of AtPRMT10 is essential for repressing FLC expression and promoting flowering in Arabidopsis.
基金This study was supported by grants from the Natural Science Foundation of Huzhou City，the Public Welfare Technical Applied Research Project of Huzhou City （No.2013GY 19 No.2013（3Z14）.Conflict of Interest：None declared
基金Supported by the National Natural Science Foundation of China,No. 81472844
文摘BACKGROUND Immunotherapy targeting programmed death-1(PD-1)or programmed deathligand-1(PD-L1)has been shown to be effective in a variety of malignancies but has poor efficacy in pancreatic ductal adenocarcinoma(PDAC).Studies have shown that PD-L1 expression in tumors is an important indicator of the efficacy of immunotherapy.Tumor cells usually evade chemotherapy and host immune surveillance by epigenetic changes.Protein arginine methylation is a common posttranslational modification.Protein arginine methyltransferase(PRMT)1 is deregulated in a wide variety of cancer types,whose biological role in tumor immunity is undefined.AIM To investigate the combined effects and underlying mechanisms of anti-PD-L1 and type I PRMT inhibitor in pancreatic cancer in vivo.METHODS PT1001B is a novel type I PRMT inhibitor with strong activity and good selectivity.A mouse model of subcutaneous Panc02-derived tumors was used to evaluate drug efficacy,toxic and side effects,and tumor growth in vivo.By flow cytometry,we determined the expression of key immune checkpoint proteins,detected the apoptosis in tumor tissues,and analyzed the immune cells.Immunohistochemistry staining for cellular proliferation-associated nuclear protein Ki67,TUNEL assay,and PRMT1/PD-L1 immunofluorescence were used to elucidate the underlying molecular mechanism of the antitumor effect.RESULTS Cultured Panc02 cells did not express PD-L1 in vitro,but tumor cells derived from Panc02 transplanted tumors expressed PD-L1.The therapeutic efficacy of anti-PD-L1 mAb was significantly enhanced by the addition of PT1001B as measured by tumor volume(1054.00±61.37 mm3 vs 555.80±74.42 mm3,P<0.01)and tumor weight(0.83±0.06 g vs 0.38±0.02 g,P<0.05).PT1001B improved antitumor immunity by inhibiting PD-L1 expression on tumor cells(32.74%±5.89%vs 17.95%±1.92%,P<0.05).The combination therapy upregulated tumorinfiltrating CD8+T lymphocytes(23.75%±3.20%vs 73.34%±4.35%,P<0.01)and decreased PD-1+leukocytes(35.77%±3.30%vs 6.48%±1.08%,P<0.001)in tumor tissue compared to the control.In addition,PT1001B amplified the inhibitory effect of anti-PD-L1 on tumor cell proliferation and enhanced the induction of tumor cell apoptosis.PRMT1 downregulation was correlated with PD-L1 downregulation.CONCLUSION PT1001B enhances antitumor immunity and combining it with anti-PD-L1 checkpoint inhibitors provides a potential strategy to overcome anti-PD-L1 resistance in PDAC.
文摘目的 探讨外周血单核细胞DNA甲基化转移酶1(DNMT1)及血清白介素-6(IL-6)在糖尿病肾脏病(DKD)中的表达及临床意义。方法 选取150例DKD患者(DKD组)及50例同期健康体检者(对照组)。比较2组IL-6、DNMT1、总胆固醇、三酰甘油、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)、血肌酐、空腹血糖、肾小球滤过率估计值(e GFR)、24 h尿白蛋白排泄率(24 h UAER)的差异。Pearson相关分析IL-6、DNMT1与其他临床指标的相关性。多因素Logistic回归分析DKD发生的影响因素。受试者工作特征(ROC)曲线分析24 h UAER、IL-6、DNMT1及联合检测对DKD的诊断价值。结果 与对照组比较,DKD组的空腹血糖、IL-6、DNMT1、血肌酐、24 h UAER、LDL-C、糖化血红蛋白水平升高,而eGFR、HDL-C水平降低(均P<0.05)。DKD组的IL-6与DNMT1呈正相关(r=0.560,P<0.05);且IL-6、DNMT1与24 h UAER呈正相关(r分别为0.551和0.570,P<0.05)。24 h UAER、IL-6及DNMT1升高是影响DKD发生的独立危险因素(P<0.05)。24 h UAER、IL-6、DNMT1联合检测诊断DKD的曲线下面积优于单一指标检测。结论 DKD患者DNMT1、IL-6水平升高,24 h UAER、DNMT1、IL-6联合检测可作为临床诊断DKD的良好指标。
基金Supported by National Natural Science Foundation of China,No.30470950
文摘AIM:To explore the relationship between DNA methyltransferase 1 (DNMT1) and hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) and its biological significance in primary HCC.METHODS: We carried out an immunohistochemical examination of DNMT1 in both HCC and paired non-neoplastic liver tissues from Chinese subjects. DNMT1 mRNA was further examined in HCC cell lines by real-time PCR. We inhibited DNMT1 using siRNA and detected the effect of depletion of DNMT1 on cell proliferation ability and cell apoptosis in the HCC cell line SMMC-7721.RESULTS: DNMT1 protein expression was increased in HCCs compared to histologically normal non-neoplastic liver tissues and the incidence of DNMT1 immunoreactivity in HCCs correlated signifi cantly with poor tumor differentiation (P=0.014). There were more cases with DNMT1 overexpression in HCC with HBV (42.85%) than in HCC without HBV (28.57%). However, no signif icant difference in DNMT1 expression was found in HBV-positive and HBV-negative cases in the Chinese HCC group. There was a trend that DNMT1 RNA expression increased more in HCC cell lines than in pericarcinoma cell lines and normal liver cell lines. In addition, we inhibited DNMT1 using siRNA in the SMMC-7721 HCC cell line and found depletion of DNMT1 suppressed cells growth independent of expression of proliferating cell nuclear antigen (PCNA), even in HCC cell lines where DNMT1 was stably decreased.CONCLUSION: The f indings implied that DNMT1 plays a key role in HBV-related hepatocellular tumorigenesis. Depletion of DNMT1 mediates growth suppression in SMMC-7721 cells.
