AIM:To report that Lpcat1 plays an important role in regulating lipopolysaccharide (LPS) inducible gene tran-scription. METHODS:Gene expression in Murine Lung Epithelial MLE-12 cells with LPS treatment or Haemophilus ...AIM:To report that Lpcat1 plays an important role in regulating lipopolysaccharide (LPS) inducible gene tran-scription. METHODS:Gene expression in Murine Lung Epithelial MLE-12 cells with LPS treatment or Haemophilus influenza and Escherichia coli infection was analyzed by employing quantitative Reverse Transcription Polymerase Chain Reaction techniques. Nucleofection was used to deliver Lenti-viral system to express or knock down Lpcat1 in MLE cells. Subcellular protein fractionation and Western blotting were utilized to study Lpcat1 nuclear relocation. RESULTS:Lpcat1 translocates into the nucleus from thecytoplasm in murine lung epithelia (MLE) after LPS treatment. Haemophilus influenza and Escherichia coli , two LPS-containing pathogens that cause pneumonia, triggered Lpcat1 nuclear translocation from the cytoplasm. The LPS inducible gene expression profile was determined by quantitative reverse transcription polymerase chain reaction after silencing Lpcat1 or overexpression of the enzyme in MLE cells. We detected that 17 out of a total 38 screened genes were upregulated, 14 genes were suppressed, and 7 genes remained unchanged in LPS treated cells in comparison to controls. Knockdown of Lpcat1 by shRNA dramatically changed the spectrum of the LPS inducible gene transcription, as 18 genes out of 38 genes were upregulated, of which 20 genes were suppressed or unchanged. Notably, in Lpcat1 overex-pressed cells, 25 genes out of 38 genes were reduced in the setting of LPS treatment.CONCLUSION:These observations suggest that Lpcat1 relocates into the nucleus in response to bacterial infection to differentially regulate gene transcriptional repression.展开更多
Flowering locus C(FLC)is a central transcriptional repressor that controls flowering time.However,how FLC is imported into the nucleus is unknown.Here,we report that Arabidopsis nucleoporins 62(NUP62),NUP58,and NUP54 ...Flowering locus C(FLC)is a central transcriptional repressor that controls flowering time.However,how FLC is imported into the nucleus is unknown.Here,we report that Arabidopsis nucleoporins 62(NUP62),NUP58,and NUP54 composed NUP62-subcomplex modulates FLC nuclear import during floral transition in an importinα-independent manner,via direct interaction.NUP62 recruits FLC to the cytoplasmic filaments and imports it into the nucleus through the NUP62-subcomplex composed central channel.Importinβsupersensitive to ABA and drought 2(SAD2),a carrier protein,is critical for FLC nuclear import and flower transition,which facilitates FLC import into the nucleus mainly through the NUP62-subcomplex.Proteomics,RNAseq,and cell biological analyses indicate that the NUP62-subcomplex mainly mediates the nuclear import of cargos with unconventional nuclear localization sequences(NLSs),such as FLC.Our findings illustrate the mechanisms of the NUP62-subcomplex and SAD2 on FLC nuclear import process and floral transition,and provide insights into the role of NUP62-subcomplex and SAD2 in protein nucleocytoplasmic transport in plants.展开更多
Will China change its nuclear power development goal after the nuclear crisis in Japan? Yu Zhouping, former Head othe Chinese Delegation to the International Atomic Energy Agency (IAEA),and Tian jiashu, Director of th...Will China change its nuclear power development goal after the nuclear crisis in Japan? Yu Zhouping, former Head othe Chinese Delegation to the International Atomic Energy Agency (IAEA),and Tian jiashu, Director of the Nuclea Safety Center under the Ministry of Environmental Protection believe thatChina’s nuclear power展开更多
Nuclear accumulation of active Smad complexes is crucial for transduction of transforming growth factor β （TGF-β）- superfamily signals from transmembrane receptors into the nucleus. It is now clear that the nucleo...Nuclear accumulation of active Smad complexes is crucial for transduction of transforming growth factor β （TGF-β）- superfamily signals from transmembrane receptors into the nucleus. It is now clear that the nucleocytoplasmic distributions of Smads, in both the absence and the presence of a TGF-β-superfamily signal, are not static, but instead the Smads are continuously shuttling between the nucleus and the cytoplasm in both conditions. This article presents the evidence for continuous nucleocytoplasmic shuttling of Smads. It then reviews different mechanisms that have been proposed to mediate Smad nuclear import and export, and discusses how the Smad steady-state distributions in the absence and the presence of a TGF-β-superfamily signal are established. Finally, the biological relevance of continuous nucleocytoplasmic shuttling for signaling by TGF-β superfamily members is discussed.展开更多
旨在探讨热应激对H9c2心肌细胞构成型HSP70(constitutive or cognate HSPs,Hsc70)出入核及细胞凋亡的影响。以42℃作为热应激模型温度,通过转染Hsc70siRNA抑制Hsc70表达,Western blot检测细胞质和细胞核内Hsc70表达,ELISA检测细胞培养液...旨在探讨热应激对H9c2心肌细胞构成型HSP70(constitutive or cognate HSPs,Hsc70)出入核及细胞凋亡的影响。以42℃作为热应激模型温度,通过转染Hsc70siRNA抑制Hsc70表达,Western blot检测细胞质和细胞核内Hsc70表达,ELISA检测细胞培养液LDH浓度,Annexin V-FITC/PI双染法检测细胞凋亡。结果表明,正常H9c2心肌细胞质Hsc70表达量较高,细胞核中表达量很低,细胞质和细胞核Hsp72表达量非常低。热应激后细胞质Hsc70表达量无显著差异,而细胞核Hsc70热应激30和100min后极显著升高(P<0.01),热应激240min后开始降低;细胞质和细胞核Hsp72热应激后显著升高(P<0.05或P<0.01)。Hsc70抑制表达后,细胞质Hsc70水平显著降低,热应激后Hsc70入核明显减少,但仍然有入核现象;Hsc70抑制表达对细胞质和细胞核Hsp72表达无显著影响。与热应激组相比,热应激+Hsc70siRNA组LDH表达量呈升高趋势,热应激100min两组出现显著差异(P<0.05);Hsc70抑制表达后H9c2细胞在热应激后更容易发生凋亡,而且在热应激30和100min内,两组之间存在显著差异(P<0.05)。结果提示,热应激可诱使Hsc70出入细胞核,Hsc70抑制表达后热应激诱导Hsc70入核显著降低,细胞损伤加重,细胞凋亡升高。展开更多
基金Supported by A United States National Institutes of Health R01 grant HL091916 to Zhao Yan American Heart Association grant 12SDG12040330 to Zou C, in part
文摘AIM:To report that Lpcat1 plays an important role in regulating lipopolysaccharide (LPS) inducible gene tran-scription. METHODS:Gene expression in Murine Lung Epithelial MLE-12 cells with LPS treatment or Haemophilus influenza and Escherichia coli infection was analyzed by employing quantitative Reverse Transcription Polymerase Chain Reaction techniques. Nucleofection was used to deliver Lenti-viral system to express or knock down Lpcat1 in MLE cells. Subcellular protein fractionation and Western blotting were utilized to study Lpcat1 nuclear relocation. RESULTS:Lpcat1 translocates into the nucleus from thecytoplasm in murine lung epithelia (MLE) after LPS treatment. Haemophilus influenza and Escherichia coli , two LPS-containing pathogens that cause pneumonia, triggered Lpcat1 nuclear translocation from the cytoplasm. The LPS inducible gene expression profile was determined by quantitative reverse transcription polymerase chain reaction after silencing Lpcat1 or overexpression of the enzyme in MLE cells. We detected that 17 out of a total 38 screened genes were upregulated, 14 genes were suppressed, and 7 genes remained unchanged in LPS treated cells in comparison to controls. Knockdown of Lpcat1 by shRNA dramatically changed the spectrum of the LPS inducible gene transcription, as 18 genes out of 38 genes were upregulated, of which 20 genes were suppressed or unchanged. Notably, in Lpcat1 overex-pressed cells, 25 genes out of 38 genes were reduced in the setting of LPS treatment.CONCLUSION:These observations suggest that Lpcat1 relocates into the nucleus in response to bacterial infection to differentially regulate gene transcriptional repression.
基金supported by grants from the National Natural Science Foundation(31970730 and 32170721)to H.Hthe Baichuan felowship from College of Life Science and Technology,Huazhong Agricultural University to D.X。
文摘Flowering locus C(FLC)is a central transcriptional repressor that controls flowering time.However,how FLC is imported into the nucleus is unknown.Here,we report that Arabidopsis nucleoporins 62(NUP62),NUP58,and NUP54 composed NUP62-subcomplex modulates FLC nuclear import during floral transition in an importinα-independent manner,via direct interaction.NUP62 recruits FLC to the cytoplasmic filaments and imports it into the nucleus through the NUP62-subcomplex composed central channel.Importinβsupersensitive to ABA and drought 2(SAD2),a carrier protein,is critical for FLC nuclear import and flower transition,which facilitates FLC import into the nucleus mainly through the NUP62-subcomplex.Proteomics,RNAseq,and cell biological analyses indicate that the NUP62-subcomplex mainly mediates the nuclear import of cargos with unconventional nuclear localization sequences(NLSs),such as FLC.Our findings illustrate the mechanisms of the NUP62-subcomplex and SAD2 on FLC nuclear import process and floral transition,and provide insights into the role of NUP62-subcomplex and SAD2 in protein nucleocytoplasmic transport in plants.
文摘Will China change its nuclear power development goal after the nuclear crisis in Japan? Yu Zhouping, former Head othe Chinese Delegation to the International Atomic Energy Agency (IAEA),and Tian jiashu, Director of the Nuclea Safety Center under the Ministry of Environmental Protection believe thatChina’s nuclear power
文摘Nuclear accumulation of active Smad complexes is crucial for transduction of transforming growth factor β （TGF-β）- superfamily signals from transmembrane receptors into the nucleus. It is now clear that the nucleocytoplasmic distributions of Smads, in both the absence and the presence of a TGF-β-superfamily signal, are not static, but instead the Smads are continuously shuttling between the nucleus and the cytoplasm in both conditions. This article presents the evidence for continuous nucleocytoplasmic shuttling of Smads. It then reviews different mechanisms that have been proposed to mediate Smad nuclear import and export, and discusses how the Smad steady-state distributions in the absence and the presence of a TGF-β-superfamily signal are established. Finally, the biological relevance of continuous nucleocytoplasmic shuttling for signaling by TGF-β superfamily members is discussed.
