Coordinated transcriptional regulation of Hspa1a gene by multiple transcription factors: crucial roles for HSF-1, NF-Y, NF-κB, and CREB.
Coordinated transcriptional regulation of Hspa1a gene by multiple transcription factors: crucial roles for HSF-1, NF-Y, NF-κB, and CREB.
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DOI：
10.1016/j.jmb.2013.09.008
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发表时间：
2014-01
影响因子：
5.6
通讯作者：
Binu Sasi;Parshuram J Sonawane;Vinayak Gupta;B. S. Sahu;N. Mahapatra
中科院分区：
文献类型：
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作者：
Binu Sasi;Parshuram J Sonawane;Vinayak Gupta;B. S. Sahu;N. Mahapatra
虽然诱导型热休克蛋白70.3（Hsp70.3，也称为Hspa 1a）的转录水平在各种疾病状态下发生改变，但其转录调控仍然不完全清楚。在这里，我们系统地分析了Hspa 1a启动子，以确定主要顺式元件和转录因子，可能会控制组成型/诱导型基因表达。计算分析与体外延伸静脉（启动子-报告基因活性和电泳迁移率变动测定）和体内（染色质免疫沉淀分析）揭示了几种转录因子与Hspa 1a启动子基序的相互作用：HSF-1（热休克因子1）在− 114/− 97 bp和− 788/− 777 bp，NF-Y（核转录因子Y）在− 73/− 58 bp，NF-κB（核因子κ B）在− 133/− 124 bp，CREB（cAMP反应元件结合蛋白）在− 483/− 476 bp。一致的是，siRNA（小干扰RNA）介导的下调这些转录因子中的每一个引起内源性Hspa 1a表达的实质性减少。热休克诱导的Hspa 1a活化受HSF-1和NF-γ/NF-κB的协同调节。TNF-α（tumor necrosis factor-alpha）和forskolin分别以NF-κB和CREB依赖的方式增强Hspa 1 α的表达。NF-κB和CREB在心肌缺血样条件下也能激活心肌成肌细胞中的Hspa 1转录。综上所述，本研究发现了NF-κB和CREB在热休克/缺血样条件下对Hspa 1 α表达的调节作用以及多种转录因子对Hspa 1 α转录活化的协同作用，从而为Hspa 1调节机制提供了新的见解。
Although the transcript level of inducible heat shock protein 70.3 (Hsp70.3, also known as Hspa1a) is altered in various disease states, its transcriptional regulation remains incompletely understood. Here, we systematically analyzed theHspa1apromoter to identify majorciselements and transcription factors that may govern the constitutive/inducible gene expression. Computational analyses coupled with extensivein vitro(promoter–reporter activity and electrophoretic mobility shift assays) andin vivo(chromatin immunoprecipitation assays) revealed interaction of several transcription factors withHspa1apromoter motifs: HSF-1 (heat shock factor 1) at − 114/− 97 bp and − 788/− 777 bp, NF-Y (nuclear transcription factor Y) at − 73/− 58 bp, NF-κB (nuclear factor kappa B) at − 133/− 124 bp, and CREB (cAMP response element binding protein) at − 483/− 476 bp. Consistently, siRNA (small interfering RNA)-mediated down-regulation of each of these transcription factors caused substantial reduction of endogenousHspa1aexpression. Heat-shock-induced activation ofHspa1awas coordinately regulated by HSF-1 and NF-Y/NF-κB. TheHspa1aexpression was augmented by TNF-α (tumor necrosis factor-alpha) and forskolin in NF-κB and CREB-dependent manners, respectively. NF-κB and CREB also activatedHspa1atranscription in cardiac myoblasts upon exposure to ischemia-like conditions. Taken together, this study discovered previously unknown roles for NF-κB and CREB to regulateHspa1aexpression and a coordinated action by several transcription factors forHspa1atransactivation under heat-shock/ischemia-like conditions and thereby provided new insights into the mechanism ofHspa1aregulation.