B cell activating factor (BAFF) gene promoter activity depends upon co-activator, p300
B cell activating factor (BAFF) gene promoter activity depends upon co-activator, p300
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DOI：
10.1016/j.imbio.2007.06.002
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发表时间：
2007-01-01
期刊：
影响因子：
2.8
通讯作者：
Park, Hyunsung
中科院分区：
文献类型：
--
作者：
Moon, Eun-Yi;Park, Hyunsung
B细胞活化因子（BAFF）在成熟B细胞的生成和维持中起着关键作用。我们先前已经描述了Toll样受体4（TLR 4）激动剂脂多糖（LPS）通过活性氧（ROS）产生和NF-κ B激活增加小鼠BAFF（mBAFF）转录物表达。在此，我们研究了mBAFF的表达是否可以通过NF-κ B B和p300（各种转录因子的共激活因子）的协同作用通过启动子激活来调节。我们将mBAFF启动子克隆到pGL 3-basic表达载体中，并对其NF-κ B结合基序进行了计算机分析。由于NF-κ B结合基序的存在，2.0 kb mBAFF启动子的活性高于1.0和0.5 kb mBAFF启动子。当用LPS刺激Raw 264.7小鼠巨噬细胞时，2.0 kb mBAFF启动子活性呈时间依赖性增加。产生ROS的血清剥夺（0.5%FBS）和外源性H2 O2处理也增强mBAFF启动子活性，这被众所周知的ROS清除剂N-乙酰基-L-半胱氨酸（NAC）降低。LPS和血清饥饿的ROS产生增加NF-κ B活化。mBAFF启动子活性通过与p65和/或共激活因子p300共转染而增强。它被显性负性（DN）p300抑制。染色质免疫沉淀法（ChIP）检测p300与BAFF启动子的结合。数据表明，mBAFF的表达可以通过NF-κ B B激活的启动子激活来调节，这可能依赖于与辅激活因子p300的合作。（0 2007 Elsevier GmbH. All rights reserved.
B-cell activating factor (BAFF) plays a critical role for mature B cell generation and maintenance. We have previously described that mouse BAFF (mBAFF) transcript expression was increased by toll-like receptor 4 (TLR4) agonist, lipopolysaccharide (LPS), through reactive oxygen species (ROS) production and NF-kappa B activation. Here, we investigated whether mBAFF expression could be regulated by promoter activation through the cooperation of NF-kappa B and p300, co-activator to various transcription factors. We cloned mBAFF promoter into luciferase-expressing pGL3-basic vector and computer-analyzed its NF-kappa B binding motif. Due to the existence of NF-kappa B binding motifs, activity in 2.0 kb mBAFF promoter was higher than that in 1.0 or 0.5 kb mBAFF promoter. When Raw 264.7 murine macrophages were stimulated with LPS, 2.0 kb mBAFF promoter activity was increased time dependently. Serum deprivation (0.5% FBS) producing ROS and exogenous H2O2 treatment also enhanced mBAFF promoter activity, which was reduced by N-acetyl-L-eysteine (NAC), a well-known ROS scavenger. LPS and serum-starved ROS production increased NF-kappa B activation. mBAFF promoter activity was augmented by co-transfection with p65 and/or co-activator, p300. It was inhibited by dominant negative (DN) p300. Binding of p300 to BAFF promoter was detected by chromatin immunoprecipitation (ChIP) assay. Data suggest that mBAFF expression could be regulated by promoter activation through NF-kappa B activation, which might be dependent on the cooperation with co-activator, p300. (0 2007 Elsevier GmbH. All rights reserved.