Objective To investigate the regulation effect of protein kinase ERK on the activation of transcription factor STAT3 in response to IL-6 in the Sko-007 human myeloma cell *** Electrophoretic mobility shift assay (EM...
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Objective To investigate the regulation effect of protein kinase ERK on the activation of transcription factor STAT3 in response to IL-6 in the Sko-007 human myeloma cell *** Electrophoretic mobility shift assay (EMSA) and immunoprecipitation (IP) were used to show the activation of STAT3 and ERK in Sko-007 cells in the presence and absence of IL-6. Antisense oligonucloetides of ERK (ERK-AS) were transfected into Sko-007 cells to specifically inhibit the expression and activity of ERK. The changes in the activation of STAT3 in the transfected cells were also exhibited by EMSA. Direct binding between STAT3 and ERK was analyzed by *** Both STAT3 and ERK were activated in Sko-007 cells stimulated with IL-6. ERK-AS inhibited STAT3 activation by IL-6. Moreover, activated ERK could form a complex with STAT3 in Sko-007 *** ERK can bind STAT3 directly and be required for its maximal activation in Sko-007 cells stimulated by IL-6.
Objective To study the selective toxicity of immunotoxin (IT) on T cells in cord blood and simultaneously determine its effect on hematopoietic progenitor cells Methods The percentage of CD 5 and CD 8 T c...
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Objective To study the selective toxicity of immunotoxin (IT) on T cells in cord blood and simultaneously determine its effect on hematopoietic progenitor cells Methods The percentage of CD 5 and CD 8 T cell subsets in cord blood (CB) and bone marrow (BM) as well as peripheral blood (PB) was measured by immunoenzymatic labeling of monoclonal antibodies using immune complexes of alkaline phosphatase and monoclonal anti alkaline phosphatase (APAAP complexes) One way mixed lymphocyte cultures (MLC) were performed to compare the proliferative response of CB with that of PB The proliferative capability of cord blood T cells and T lymphocyte transformation capacity were evaluated in the presence of anti CD 8 or anti CD 5 immunotoxin by one way MLC and colorimetric MTT (tetrazolium) assay, respectively The effect of IT on the growth of hematopoietic progenitor cell of colony forming unit granulocyte and macrophage (CFU GM), burst forming unit erythroid(BFU E), multipotential hemotapoietic progenitors (CFU Mix) from CB were estimated by colony forming assays Results A certain proportion of CD 5 and CD 8 T cells existed in CB The alloproliferative capacity of CB was similar to that of PB CD 5: Ricin at a dosage of 1×10 10 -1×10 8 mmol/L and CD 8: Ricin concentration in the range of 1×10 9 -1×10 8 mmol/L effectively decreased both the proliferative capability of T cells in MLC during CB and T cell transformation Over the dosage of 1×10 10 -1×10 9 mmol/L, both kinds of IT didn't obviously affect the growth of hematopoietic progenitor cells Conclusion CD 5: Ricin and CD 8: Ricin may effectively deplete T cells and may not significantly inhibit the function of hemaptopoietic cells at a specific dosage
STAT3(signal transducers and activators of transcription) 是胞浆中的潜在转录因子,在细胞因子、生长因子等外界信号分子的刺激下发生磷酸化和二聚化进入细胞核,结合在基因特定的启动子上调控转录.目前对STAT3的磷酸化和二聚化都相...
详细信息
STAT3(signal transducers and activators of transcription) 是胞浆中的潜在转录因子,在细胞因子、生长因子等外界信号分子的刺激下发生磷酸化和二聚化进入细胞核,结合在基因特定的启动子上调控转录.目前对STAT3的磷酸化和二聚化都相当清楚,但对其怎样进入细胞核还知之甚少.入核分子一般都有一段碱性氨基酸的核定位序列(NLS),但通过比较STAT家族没有发现经典的核定位序列(NLS).以IL-6为外界信号分子,293T为细胞模型,绿色荧光蛋白GFP为标签分子,研究发现STAT3分子在IL-6刺激前呈胞浆分布,刺激后聚集胞核中是由于构象的改变暴露了核定位序列.通过同源比较和缺失突变发现,位于STAT3 DNA结合域403～426位氨基酸之间的一段富含赖氨酸和精氨酸的碱性氨基酸对STAT3入核起重要作用,具有核定位序列(NLS)的功能.
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