Poly(C) binding protein family is a transcription factor in μ-opioid receptor gene expression
Poly(C) binding protein family is a transcription factor in μ-opioid receptor gene expression
复制标题
DOI：
10.1124/mol.105.012245
复制
发表时间：
2005-09-01
影响因子：
3.6
通讯作者：
Loh, HH
中科院分区：
文献类型：
--
作者：
Kim, SS;Pandey, KK;Loh, HH
小鼠 mu-阿片受体 (MOR) 基因有两个启动子，称为远端启动子和近端启动子。此前，我们的同事报道称，小鼠 MOR 基因的 26 个碱基对 (bp) 顺式作用元件可激活 MOR 基因表达。在这里，我们报告了聚 (C) 结合蛋白 (PCBP) 家族的四个成员的克隆，并表明 MOR 近端启动子中的 26 bp 聚嘧啶片段与这些 PCBP 相互作用并激活 MOR 转录。 PCBP 不仅与单链 DNA 结合，还与双链 DNA 结合。核流失实验和半定量RT-PCR表明PCBPs提高了MOR基因的转录率。此外，我们进行了精细定位，以阐明参与介导 PCBP 诱导的 MOR 启动子活性的核心区域 (-317/-304)。针对多嘧啶延伸段的诱饵寡核苷酸抑制 PCBP 诱导的 MOR 启动子活性，从而再次证实了该元件在调节 MOR 启动子活性中的作用。染色质免疫沉淀测定证实了 PCBP 与体内 MOR 启动子的相互作用。总之，我们证明 PCBP 作为转录因子并正向调节 NMB 细胞中的 MOR 基因表达。
The mouse mu-opioid receptor (MOR) gene has two promoters, referred to as distal and proximal promoter. Previously, our colleagues reported that a 26-base pair (bp) cis-acting element of the mouse MOR gene activates MOR gene expression. Here, we report the cloning of four members of the poly(C) binding protein (PCBP) family and show that the 26-bp polypyrimidine stretch in MOR proximal promoter interacts with these PCBPs and activates MOR transcription. The PCBPs bind not only to single-stranded but also to double-stranded DNA. The nuclear run-off assay and semiquantitative RT-PCR shows that PCBPs enhance the transcription rate of MOR gene. Furthermore, we performed refined mapping to elucidate the core region (-317/-304) involved in mediating the PCBP-induced MOR promoter activity. Decoy oligonucleotides against the polypyrimidine stretch inhibit the PCBP-induced MOR promoter activity, thereby reconfirming the role of this element in regulating MOR promoter activity. Chromatin immunoprecipitation assay confirmed the interaction of PCBPs with MOR promoter in vivo. In conclusion, we demonstrate that PCBPs act as a transcription factor and positively regulate MOR gene expression in NMB cells.