ABSTRACT
MYB transcription factors, one of the largest transcription factor families in plants, play an important role in signal transduction, plant growth and plant resistance. In this study a full-length cDNA of the PnMYB1R1 gene was cloned from Panax notoginseng. Sequence analysis, prokaryotic expression and purification, subcellular location, transcriptional activity analysis, tissue-specific analysis and expression analysis under different abiotic stresses was performed. The open reading frame (ORF) of PnMYB1R gene was 738 bp, encoding a protein of 245 amino acids with a predicted molecular mass (MW) of 27.0 kD. The sequence analysis and polygenetic analysis indicated that the PnMYB1R1 protein contains a conserved R3 domain, belonging to TRF-like protein in 1R-MYB-type transcription factors. The recombinant PnMYB1R1 protein was expressed in Escherichia coli BL21(DE3) cells using the prokaryotic expression vector pET28a-PnMYB1R1 and was purified. Subcellular localization analysis showed that PnMYB1R1 was localized in the nucleus. Transcriptional activity analysis indicated that the PnMYB1R1 transcription factor has transcriptional activation activity. Expression analysis indicated that PnMYB1R1 was primarily expressed in roots, followed by stems and leaves, and then rootlets. The expression level of PnMYB1R1 in root, stems, leaves and rootlets was influenced by salt, low temperature and drought treatment, while the abundance of PnMYB1R1 was significantly induced by salt stress in these tissues. These results provide valuable insights into the role of 1R-MYB transcription factors in plant defense.
ABSTRACT
Objective To construct expression vectors of human ribosomal protein S 3(RPS3) and RPS3Ser209 mutant in orcler to investigate the effect of RPS3Ser209 mutant on NF-κB signaling pathway and DNA binding capacity .Methods The vector RPS3-myc was amplified by polymerase chain reaction ( PCR) from the human liver cDNA and subcloned into pcDNA-3.1myc-HisB.RPS3S209A represented mutant RPS3 expression vectors, in which the designated amino acid was mutated to an alanine residue .Dual luciferase reporter gene assay was used to detect the NF-κB transcription activity in HEK293 cells,immunofluorescence to detect RPS3 location, and EMSA to examine NF-κB DNA-binding activity.Results The expression vectors of RPS3-myc and RPS3S209A-myc were constructed.Compared with wild-type RPS3,the nucleus translocation, transactivation activity of NF-κB and DNA binding ability of RPS3S290A were reduced significantly .Conclu-sion The impact of RPS3 on NF-κB signaling pathway depend on its serine 209.
ABSTRACT
Objective To confirm the interaction betweem NLK and Smad 4 and to explore the effect of NLK on the function of Smad4.Methods Co-immunoprecipitation and GST Pull-down were used to detect the interaction between NLK and Smad4.GST Pull-down was used to map the domain through which Smad 4 interacts with NLK.Luciferase reporter gene assay was used to study the effect of NLK and NLK (KM), the NLK mutant lacking kinase activity , on the transcrip-tion activity of Smad4.In vivo phosphorylation assay was used to detect whether NLK phosphorylated Smad 4 or not.Results The data of Co-immunoprecipitation and GST Pull-down showed that NLK interacted with Smad 4 in vivo and in vitro.The result of GST Pull-down showed that Smad4 interacted with NLK via MH2 domain.The results of luciferase reporter gene assay indicated that both NLK and NLK (KM) inhibited the transcription activity of Smad4.The result of in vivo phospho-rylation assay showed that NLK could not phosphorylate Smad 4 in vivo.Conclusion NLK interacts with Smad4 and inhibits the transcription activity of Smad 4 independent of the kinase activity of NLK .The mechanism through which NLK negatively regulates the transcription of Smad 4 requires further research .
ABSTRACT
In this study, we report the development of a new dual reporter vector system for the analysis of promoter activity. This system employs green fluorescence emitting protein, EGFP, as a reporter, and uses red fluorescence emitting protein, DsRed, as a transfection control in a single vector. The expression of those two proteins can be readily detected via flow cytometry in a single analysis, with no need for any further manipulation after transfection. As this system allows for the simultaneous detection of both the control and reporter proteins in the same cells, only transfected cells which express the control protein, DsRed, can be subjected to promoter activity analysis, via the gating out of all un-transfected cells. This results in a dramatic increase in the promoter activity detection sensitivity. This novel reporter vector system should prove to be a simple and efficient method for the analysis of promoter activity.
Subject(s)
Enzyme Multiplied Immunoassay Technique , Flow Cytometry , Fluorescence , Luminescent Proteins , Proteins , TransfectionABSTRACT
To study the changes in serum immunosuppressive acidic protein (IAP) and T lymphocytes rDNA transcription activity in peripheral blood of patients with pancreatic cancer before and after operation. The level of IAP and T lymphocytes rDNA transcription activity in peripheral blood of 58 patients with pancreatic cancer were measured before and after opreration by one directional immunodiffusion test and a cell image analysis of Ag NORs, respectively, and the results were compared with that of healthy controls. The level of IAP was higher while T lymphocytes rDNA transcription activity was lower before operation compared with healthy controls( P 0 05). The levels of IAP and T lymphocytes rDNA transcription activity were closely related to tumor invasion, metastasis and clinical stages (TNM). Serial determination of the levels of IAP and T lymphocytes rDNA transcription activity might serve as an important index for evalution of tumor invasion and metatasis, and also prognosis for the patients with pancreatic cancer