Constitutive activation of LIL-Stat in adult T cell leukemia cells

成人 T 细胞白血病细胞中 LIL-Stat 的组成型激活

基本信息

批准号：
10670976
负责人：
TSUKADA Junichi
金额：
$ 1.98万
依托单位：
University of Occupational and Environmental Health
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10670976/
关键词：
adult T cell leukemia interleukin 1 gene transcription cvtokine STAT Receptor leukemia signal transduction インターロイキン 1 インターロイキン

项目摘要

Binding of many cytokines to their cognate receptors immediately activates Jak tyrosine kinases and their substrates ; namely, STAT (signal transducers and activators of transcription) DNA binding proteins. The activated STAT proteins dimerize and are translocated to the nucleus in order to transactivate genes by binding to variations on the gamma interferon (IFN-γ) activation site (GAS).We have recently demonstrated that both lipopolysaccharide (LPS) and IL-1 immediately activate a common novel STAT factor. This LPS/IL-1 inducible factor (LIL-Stat) binds a GAS-like sequence (TTCCTGAGA) termed LILRE (LPS and IL-1 responsive element) in the human prointerleukin 1β (IL1B) gene and is recognized by an antibody (Ab) raised to the N-terminus of Stat1 (anti-Stat1N Ab), but not by those specific for either the C terminus of Stat1 (anti-Stat1C Ab) or any other GAS-binding STAT.The DNA-binding activity of this protein is inhibited by phosphotyrosine, suggesting that phosphotyrosine mediates the … More obligate dimerization required for STAT DNA binding. Analysis of DNA binding specificity has demonstrated that the LIL-Stat possesses a novel GAS-like binding activity that contrasts with that of other STATs in a requirement for a G residue at position 8. The existence of such a factor relates the signaling pathway for IL-1 and LPS receptors to other cytokine receptors that mediate signaling via the immediate activation of STAT transcriptional factors.In the present study, we investigated LIL-Stat activation status in ATL cells by electrophoretic mobility shift assay (EMSA) using a radiolabeled LILRE probe and ATL cell nuclear extracts. The functional role of LIL-Stat in ATL cells was further assessed by transient transfection studies using LILRE chloramphenicol acetyltransferase (CAT) reporters. As a result, spontaneous DNA binding of LIL-Stat was observed in all ATL cells examined. However, in normal human peripheral lymphocytes, DNA binding of LIL-Stat was detected only after stimulation with IL-1. These results demonstrated that LIL-Stat is constitutively activated in ATL cells. Furthermore, our transient transfection studies using LILRE chloramphenicol acetyltransferase (CAT) reporters argue that LIL-Stat in ATL cells functions as a transcriptional activator through binding to the LILRE in the IL1B gene. Less

许多细胞因子与其同源受体的结合立即激活Jak酪氨酸激酶及其底物。也就是说，STAT（转录的信号换能器和活化剂）DNA结合蛋白。活化的STAT蛋白二聚并易位到细胞核，以通过与伽马干扰素（IFN-γ）激活位点（GAS）的变化结合来反式激活基因。我们最近证明了脂多糖酸（LPS）（LPS）（LPS）和IL-1立即激活了常见的新型统计因子。该LPS/IL-1诱导因子（LIL-STAT）结合了人类Prointerleukin1β（IL1B）基因中称为Lilre（LPS和IL-1响应元件）的气体样序列（TTCCTGAGA），并被抗体（AB）识别为抗体（AB），该抗体（AB）均由abs1（ab）（均为AB）（均不适合AB）（均未）（均为AN-terminus of Absinus of Absinus of Absinus of Absinus of Anti1n），但Anti STAT1N的抗体，但Anti anti STAT1N，但抗体，但Anti and anti STATAT1N，但抗体（ab）却被抗体（ab）的抗体（但（抗STAT1C AB）或任何其他气体结合统计。该蛋白的DNA结合活性受到磷酸酪氨酸的抑制，这表明磷酸酪氨酸介导了STAT DNA结合所需的……更强大的二聚体。 DNA结合特异性的分析表明，LIL-Stat具有一种新型的气体样结合活性，该活性与其他统计数据在第8位的G居住条件中与其他统计数据形成鲜明对比。存在此类因素与IL-1和LPS受体的信号传导途径的存在相关，该信号传导途径与其他细胞受到介导的细胞介导的统计激活因素，以介导其他细胞的信号。电泳迁移率转移评估（EMSA）使用放射标记的Lilre探针和ATL细胞核提取物。通过使用Lilre氯霉素乙酰基转移酶（CAT）记者，通过短暂转染研究进一步评估LIL-STAT在ATL细胞中的功能作用。结果，在检查的所有ATL细胞中都观察到了基于赞助者的LIL-Stat的DNA结合。然而，在正常的人外周淋巴细胞中，仅在用IL-1刺激后才检测到LIL-STAT的DNA结合。这些结果表明，LIL-STAT在ATL细胞中始终激活。此外，我们使用Lilre氯霉素乙酰基转移酶（CAT）记者的瞬时翻译研究认为，ATL细胞中的LIL-STAT通过与IL1B基因中的LILRE结合而起作用作为转录激活剂。较少的