SMYD(SET and MYND domain containing,SMYD)是一类含有SET功能域的蛋白,在染色体的调节、基因的表达、细胞生长周期的控制、细胞的分裂、分化及发育等方面具有重要作用.目前已知在果蝇、脊椎动物中均含有Smyd基因,且这些基因的进化、...SMYD(SET and MYND domain containing,SMYD)是一类含有SET功能域的蛋白,在染色体的调节、基因的表达、细胞生长周期的控制、细胞的分裂、分化及发育等方面具有重要作用.目前已知在果蝇、脊椎动物中均含有Smyd基因,且这些基因的进化、表达及功能均有很多研究,但关于脊索动物SMYD家族基因的研究则很少.本文对头索动物文昌鱼的基因组进行搜索,发现文昌鱼有6个可能的Smyd基因.对Smyd基因在染色体上的位置分析结果显示:文昌鱼Smyd相关基因同其他已经研究过的物种如爪蟾、小鼠、人等一样,均是散在分布于不同的染色体上.对这些基因的功能域的分析结果显示:文昌鱼的3个Smyd基因,斑马鱼的2个Smyd基因和人的4个Smyd基因除了含有SET功能域之外,还有另外一个SCOP功能域.基因结构的分析表明:脊椎动物的基因结构比较保守,但无脊椎动物及脊索动物的基因结构则保守性较差.而系统进化分析的结果则显示,文昌鱼Smyd相关的6个基因中只有两个与其他物种同源性较高,其余四个则相对较低.本文旨在对文昌鱼SMYD家族基因进行初步的系统进化分析,但脊索动物文昌鱼的Smyd基因在体内到底执行什么样的功能,其功能又是如何实现的,都有待于进一步研究.展开更多
Lysine methylation of histones and non-histones plays a pivotal role in diverse cellular processes.The SMYD(SET and MYND domain)family methyltransferases can methylate various histone and non-histone substrates in mam...Lysine methylation of histones and non-histones plays a pivotal role in diverse cellular processes.The SMYD(SET and MYND domain)family methyltransferases can methylate various histone and non-histone substrates in mammalian systems,implicated in HSP90 methylation,myofilament organization,cancer inhibition,and gene transcription regulation.To resolve controversies concerning SMYD's substrates and functions,we studied SMYD1(TTHERM_00578660),the only homologue of SMYD in the unicellular eukaryote Tetrahymena thermophila.We epitope-tagged SMYD1,and analyzed its localization and interactome.We also characterized △SMYD1 cells,focusing on the replication and transcription phenotype.Our results show that:(1)SMYD1 is present in both cytoplasm and transcriptionally active macronucleus and shuttles between cytoplasm and macronucleus,suggesting its potential association with both histone and non-histone substrates;(2)SMYD1 is involved in DNA replication and regulates transcription of metabolism-related genes;(3)HSP90 is a potential substrate for SMYD1 and it may regulate target selection of HSP90,leading to pleiotropic effects in both the cytoplasm and the nucleus.展开更多
The SMYD(SET and MYND domain)family of lysine methyltransferases(KMTs)plays pivotal roles in various cellular processes,including gene expression regulation and DNA damage response.Initially identified as genuine hist...The SMYD(SET and MYND domain)family of lysine methyltransferases(KMTs)plays pivotal roles in various cellular processes,including gene expression regulation and DNA damage response.Initially identified as genuine histone methyltransferases,specific members of this family have recently been shown to methylate non-histone proteins such as p53,VEGFR,and the retinoblastoma tumor suppressor(pRb).To gain further functional insights into this family of KMTs,we generated the protein interaction network for three different human SMYD proteins(SMYD2,SMYD3,and SMYD5).Characterization of each SMYD protein network revealed that they associate with both shared and unique sets of proteins.Among those,we found that HSP90 and several of its co-chaperones interact specifically with the tetratrico peptide repeat(TPR)-containing SMYD2 and SMYD3.Moreover,using proteomic and biochemical techniques,we provide evidence that SMYD2 methylates K209 and K615 on HSP90 nucleotide-binding and dimerization domains,respectively.In addition,we found that each methylation site displays unique reactivity in regard to the presence of HSP90 co-chaperones,pH,and demethylation by the lysine amine oxidase LSD1,suggesting that alternative mechanisms control HSP90 methylation by SMYD2.Altogether,this study highlights the ability of SMYD proteins to form unique protein complexes that may underlie their various biological functions and the SMYD2-mediated methylation of the key molecular chaperone HSP90.展开更多
AIM： To investigate the role of SMYD3 in hepatocellular carcinoma （HCC） development and progression and to verify whether its regulation activity was through RIZ1 inactivation. METHODS： Expression of SMYD3 in HCC ...AIM： To investigate the role of SMYD3 in hepatocellular carcinoma （HCC） development and progression and to verify whether its regulation activity was through RIZ1 inactivation. METHODS： Expression of SMYD3 in HCC cell lines and tissues were measured; silencing of SMYD3 by RNA interference （RNAi） was effectuated, hepatoma cell proliferation, migration and apoptosis were tested, with RIZl CpG promoter methylation, and corresponding mRNA expression were investigated. RESULTS： SMYD3 over-expression in HCC was associated with RIZl hypermethylation and mRNA down-expression. Suppression of SMYD3 expression de- methylated RIZl CpG promoter （P 〈 0.01） and increased RIZl mRNA expression （P 〈 0.01）. Consequently, SMYD3 down-expression with RIZl de-methylation strongly inhibited hepatoma cell growth （MTT inhibitory rates： Pgenesil-1-s1 60.95%± 7.97%, Pgenesil-1-s2 72.14% ± 9.68% vs Pgenesil-1-hk 6.89% ± 4.12%, P 〈 0.01） and migration （Pgenesil-1-s1 4.24% ± 1.58%, Pgenesil- 1-s1 4.87% ± 0.73% vs Pgenesil-1 19.03% ± 4.63%, Pgenesil-1-hk 19.95% ±5.21%, P 〈 0.01） and induced apoptosis （FCM subG1 phase Pgenesil-1-s1 19.07% ＋ 1.78%, Pgenesil-1-s2 17.68% ± 2.36% vs Pgenesil-1 0.47% ± 0.12%, Pgenesil-1-hk 1.46% ± 0.28%, P 〈 0.01. TUNEL-positive cells： Pgenesil-1-s1 40.24%± 5.18%, Pgenesil-1-s2 38.48% ± 4.65% vs Pgenesil-1 2.1B% - 1.34%, Pgenesil-1-hk 2.84%± 1.22%, P 〈 0.01） in HepG2 cells. CONCLUSION： These results demonstrate that SMYD3plays a critical role in the carcinogenesis and progression of HCC, The proliferation, migration induction and apoptosis inhibition activities of SMYD3 may be mediated through RIZl CpG promoter hypermethylation.展开更多
目的:观察SMYD3(SET and MYND-domain containing3)基因沉默后c-Myc的表达及对HepG2细胞凋亡的影响.方法:构建针对SMYD3的shRNA干扰质粒Pgenesil-1-s1、Pgenesil-1-s2和阴性对照质粒Pgenesil-1-hk,同时设空白对照组,采用Lipofectamine2...目的:观察SMYD3(SET and MYND-domain containing3)基因沉默后c-Myc的表达及对HepG2细胞凋亡的影响.方法:构建针对SMYD3的shRNA干扰质粒Pgenesil-1-s1、Pgenesil-1-s2和阴性对照质粒Pgenesil-1-hk,同时设空白对照组,采用Lipofectamine2000脂质体介导转染法转染质粒.转染后24、48、72h,RT-PCR检测HepG2细胞SMYD3和c-Myc的表达情况.流式细胞术法检测各组细胞的凋亡.结果:SMYD3、c-Myc基因在HepG2细胞中强表达.RT-PCR显示Pgenesil-1-s1、Pgenesil-1-s2转染组与阴性对照质粒转染组Pgenesil-1-hk转染24、48、72h后相比,SMYD3基因表达均明显受到抑制(F=67.46,P<0.01;F=176.79,P<0.01;F=175.28,P<0.01),同时c-Myc表达下调(三组之间:F=11.58,P=0.009;F=126.41,P<0.01;F=261.25,P<0.01).Pgenesil-1-s1、Pgenesil-1-s2转染组细胞早期凋亡率与Pgenesil-1-hk转染组(LSD-t=-13.58,-12.62,均P<0.01)、空白组(LSD-t=-18.62,-17.67,均P<0.01)相比有显著性差异.结论:RNA干扰技术特异性沉默HepG2细胞SMYD3基因后,抑制了c-Myc的表达,促进了HepG2细胞的凋亡.展开更多
The SET-and myeloid-Nervy-DEAF-1(MYND)-domain containing(Smyd)lysine methyltransferases 1–3 share relatively high sequence similarity but exhibit divergence in the substrate specificity.Here we report the crystal str...The SET-and myeloid-Nervy-DEAF-1(MYND)-domain containing(Smyd)lysine methyltransferases 1–3 share relatively high sequence similarity but exhibit divergence in the substrate specificity.Here we report the crystal structure of the full-length human Smyd2 in complex with S-adenosyl-L-homocysteine(AdoHcy).Although the Smyd1–3 enzymes are similar in the overall structure,detailed comparisons demonstrate that they differ substantially in the potential substrate-binding site.The binding site of Smyd3 consists mainly of a deep and narrow pocket,while those of Smyd1 and Smyd2 consist of a comparable pocket and a long groove.In addition,Smyd2,which has lysine methyltransferase activity on histone H3-lysine 36,exhibits substantial differences in the wall of the substrate-binding pocket compared with those of Smyd1 and Smyd3 which have activity specifically on histone H3-lysine 4.The differences in the substrate-binding site might account for the observed divergence in the specificity and methylation state of the substrates.Further modeling study of Smyd2 in complex with a p53 peptide indicates that mono-methylation of p53-Lys372 might result in steric conflict of the methyl group with the surrounding residues of Smyd2,providing a structural explanation for the inhibitory effect of the SET7/9-mediated mono-methylation of p53-Lys372 on the Smyd2-mediated methylation of p53-Lys370.展开更多
文摘SMYD(SET and MYND domain containing,SMYD)是一类含有SET功能域的蛋白,在染色体的调节、基因的表达、细胞生长周期的控制、细胞的分裂、分化及发育等方面具有重要作用.目前已知在果蝇、脊椎动物中均含有Smyd基因,且这些基因的进化、表达及功能均有很多研究,但关于脊索动物SMYD家族基因的研究则很少.本文对头索动物文昌鱼的基因组进行搜索,发现文昌鱼有6个可能的Smyd基因.对Smyd基因在染色体上的位置分析结果显示:文昌鱼Smyd相关基因同其他已经研究过的物种如爪蟾、小鼠、人等一样,均是散在分布于不同的染色体上.对这些基因的功能域的分析结果显示:文昌鱼的3个Smyd基因,斑马鱼的2个Smyd基因和人的4个Smyd基因除了含有SET功能域之外,还有另外一个SCOP功能域.基因结构的分析表明:脊椎动物的基因结构比较保守,但无脊椎动物及脊索动物的基因结构则保守性较差.而系统进化分析的结果则显示,文昌鱼Smyd相关的6个基因中只有两个与其他物种同源性较高,其余四个则相对较低.本文旨在对文昌鱼SMYD家族基因进行初步的系统进化分析,但脊索动物文昌鱼的Smyd基因在体内到底执行什么样的功能,其功能又是如何实现的,都有待于进一步研究.
基金supported by the Natural Science Foundation of Shandong Province(JQ201706 to SG)Fundamental Research Funds for the Central Universities(201841013 to SG)+1 种基金National Science Foundation[MCB 1411565 to YL]National Institutes of Health Foundation[R01 GM087343 to YL].
文摘Lysine methylation of histones and non-histones plays a pivotal role in diverse cellular processes.The SMYD(SET and MYND domain)family methyltransferases can methylate various histone and non-histone substrates in mammalian systems,implicated in HSP90 methylation,myofilament organization,cancer inhibition,and gene transcription regulation.To resolve controversies concerning SMYD's substrates and functions,we studied SMYD1(TTHERM_00578660),the only homologue of SMYD in the unicellular eukaryote Tetrahymena thermophila.We epitope-tagged SMYD1,and analyzed its localization and interactome.We also characterized △SMYD1 cells,focusing on the replication and transcription phenotype.Our results show that:(1)SMYD1 is present in both cytoplasm and transcriptionally active macronucleus and shuttles between cytoplasm and macronucleus,suggesting its potential association with both histone and non-histone substrates;(2)SMYD1 is involved in DNA replication and regulates transcription of metabolism-related genes;(3)HSP90 is a potential substrate for SMYD1 and it may regulate target selection of HSP90,leading to pleiotropic effects in both the cytoplasm and the nucleus.
基金supported by a Canadian Institutes for Health Research grant (GMX-209406 to J.-F.C.and D.F.).
文摘The SMYD(SET and MYND domain)family of lysine methyltransferases(KMTs)plays pivotal roles in various cellular processes,including gene expression regulation and DNA damage response.Initially identified as genuine histone methyltransferases,specific members of this family have recently been shown to methylate non-histone proteins such as p53,VEGFR,and the retinoblastoma tumor suppressor(pRb).To gain further functional insights into this family of KMTs,we generated the protein interaction network for three different human SMYD proteins(SMYD2,SMYD3,and SMYD5).Characterization of each SMYD protein network revealed that they associate with both shared and unique sets of proteins.Among those,we found that HSP90 and several of its co-chaperones interact specifically with the tetratrico peptide repeat(TPR)-containing SMYD2 and SMYD3.Moreover,using proteomic and biochemical techniques,we provide evidence that SMYD2 methylates K209 and K615 on HSP90 nucleotide-binding and dimerization domains,respectively.In addition,we found that each methylation site displays unique reactivity in regard to the presence of HSP90 co-chaperones,pH,and demethylation by the lysine amine oxidase LSD1,suggesting that alternative mechanisms control HSP90 methylation by SMYD2.Altogether,this study highlights the ability of SMYD proteins to form unique protein complexes that may underlie their various biological functions and the SMYD2-mediated methylation of the key molecular chaperone HSP90.
基金National Natural Science Foundation of China, No 30200273 & 30672067
文摘AIM： To investigate the role of SMYD3 in hepatocellular carcinoma （HCC） development and progression and to verify whether its regulation activity was through RIZ1 inactivation. METHODS： Expression of SMYD3 in HCC cell lines and tissues were measured; silencing of SMYD3 by RNA interference （RNAi） was effectuated, hepatoma cell proliferation, migration and apoptosis were tested, with RIZl CpG promoter methylation, and corresponding mRNA expression were investigated. RESULTS： SMYD3 over-expression in HCC was associated with RIZl hypermethylation and mRNA down-expression. Suppression of SMYD3 expression de- methylated RIZl CpG promoter （P 〈 0.01） and increased RIZl mRNA expression （P 〈 0.01）. Consequently, SMYD3 down-expression with RIZl de-methylation strongly inhibited hepatoma cell growth （MTT inhibitory rates： Pgenesil-1-s1 60.95%± 7.97%, Pgenesil-1-s2 72.14% ± 9.68% vs Pgenesil-1-hk 6.89% ± 4.12%, P 〈 0.01） and migration （Pgenesil-1-s1 4.24% ± 1.58%, Pgenesil- 1-s1 4.87% ± 0.73% vs Pgenesil-1 19.03% ± 4.63%, Pgenesil-1-hk 19.95% ±5.21%, P 〈 0.01） and induced apoptosis （FCM subG1 phase Pgenesil-1-s1 19.07% ＋ 1.78%, Pgenesil-1-s2 17.68% ± 2.36% vs Pgenesil-1 0.47% ± 0.12%, Pgenesil-1-hk 1.46% ± 0.28%, P 〈 0.01. TUNEL-positive cells： Pgenesil-1-s1 40.24%± 5.18%, Pgenesil-1-s2 38.48% ± 4.65% vs Pgenesil-1 2.1B% - 1.34%, Pgenesil-1-hk 2.84%± 1.22%, P 〈 0.01） in HepG2 cells. CONCLUSION： These results demonstrate that SMYD3plays a critical role in the carcinogenesis and progression of HCC, The proliferation, migration induction and apoptosis inhibition activities of SMYD3 may be mediated through RIZl CpG promoter hypermethylation.
文摘目的:观察SMYD3(SET and MYND-domain containing3)基因沉默后c-Myc的表达及对HepG2细胞凋亡的影响.方法:构建针对SMYD3的shRNA干扰质粒Pgenesil-1-s1、Pgenesil-1-s2和阴性对照质粒Pgenesil-1-hk,同时设空白对照组,采用Lipofectamine2000脂质体介导转染法转染质粒.转染后24、48、72h,RT-PCR检测HepG2细胞SMYD3和c-Myc的表达情况.流式细胞术法检测各组细胞的凋亡.结果:SMYD3、c-Myc基因在HepG2细胞中强表达.RT-PCR显示Pgenesil-1-s1、Pgenesil-1-s2转染组与阴性对照质粒转染组Pgenesil-1-hk转染24、48、72h后相比,SMYD3基因表达均明显受到抑制(F=67.46,P<0.01;F=176.79,P<0.01;F=175.28,P<0.01),同时c-Myc表达下调(三组之间:F=11.58,P=0.009;F=126.41,P<0.01;F=261.25,P<0.01).Pgenesil-1-s1、Pgenesil-1-s2转染组细胞早期凋亡率与Pgenesil-1-hk转染组(LSD-t=-13.58,-12.62,均P<0.01)、空白组(LSD-t=-18.62,-17.67,均P<0.01)相比有显著性差异.结论:RNA干扰技术特异性沉默HepG2细胞SMYD3基因后,抑制了c-Myc的表达,促进了HepG2细胞的凋亡.
基金supported by the grants from the Ministry of Science and Technology of China (2007CB914302 and 2011CB966301)the National Natural Science Foundation of China (30730028)+2 种基金the Chinese Academy of Sciences (SIBS2008002)the Science and Technology Commission of Shanghai Municipality (10JC1416500)support of the SA-SIBS scholarship program.
文摘The SET-and myeloid-Nervy-DEAF-1(MYND)-domain containing(Smyd)lysine methyltransferases 1–3 share relatively high sequence similarity but exhibit divergence in the substrate specificity.Here we report the crystal structure of the full-length human Smyd2 in complex with S-adenosyl-L-homocysteine(AdoHcy).Although the Smyd1–3 enzymes are similar in the overall structure,detailed comparisons demonstrate that they differ substantially in the potential substrate-binding site.The binding site of Smyd3 consists mainly of a deep and narrow pocket,while those of Smyd1 and Smyd2 consist of a comparable pocket and a long groove.In addition,Smyd2,which has lysine methyltransferase activity on histone H3-lysine 36,exhibits substantial differences in the wall of the substrate-binding pocket compared with those of Smyd1 and Smyd3 which have activity specifically on histone H3-lysine 4.The differences in the substrate-binding site might account for the observed divergence in the specificity and methylation state of the substrates.Further modeling study of Smyd2 in complex with a p53 peptide indicates that mono-methylation of p53-Lys372 might result in steric conflict of the methyl group with the surrounding residues of Smyd2,providing a structural explanation for the inhibitory effect of the SET7/9-mediated mono-methylation of p53-Lys372 on the Smyd2-mediated methylation of p53-Lys370.
文摘目的:探讨microRNA-377(miR-377)与组蛋白甲基转移酶SMYD3在肝癌中的表达规律及与肝癌的相关性.方法:利用实时定量PCR分别检测不同肝组织及肝细胞系中miR-377表达水平,应用实时定量PCR和Western blot分别检测不同肝组织及肝细胞系中SMYD3 mRNA和蛋白水平的表达情况.通过转染miR-377模拟物上调其在肝癌细胞株HepG2中表达后,应用实时定量PCR、Western blot分别检测转染前后HepG2中SMYD3 mRNA和蛋白表达的变化.结果:MiR-377 mRNA在人肝癌旁组织和肝癌组织中的表达较正常肝脏明显降低(0.331±0.059,0.139±0.064 vs 0.874±0.178,均P<0.05);在HepG2中的表达较L-02明显降低(0.145±0.021vs0.868±0.194,P<0.05).SMYD3 mRNA和蛋白质在人肝癌旁组织和肝癌组织中的表达较正常肝脏明显升高(mRNA:3.836±0.137,5.836±0.965vs1.235±0.332;蛋白:0.381±0.020,0.484±0.030vs0.252±0.015;均P<0.05).SMYD3 mRNA和蛋白质在肝癌细胞系HepG2中的表达较正常肝细胞系L-02明显升高(mRNA:0.845±0.047vs0.348±0.134;蛋白:0.575±0.008vs0.259±0.007,均P<0.05).转染miRNA-377模拟物上调HepG2中miR-377表达后转染组SMYD3 mRNA和蛋白表达较空白组和阴性对照组均明显下降(mRNA:0.125±0.010 vs 0.857±0.163,0.779±0.167;蛋白:0.092±0.026 vs 0.347±0.040,0.383±0.054,均P<0.05).结论:miRNA-377在肝癌中表达明显下调,其靶基因SMYD3表达上调;表达下调的miRNA-377丧失对SMYD3表达的抑制可能是肝癌发生的重要机制.
