Transcriptional regulation of the CADM1 gene by retinoic acid during the neural differentiation of murine embryonal carcinoma P19 cells
Transcriptional regulation of the CADM1 gene by retinoic acid during the neural differentiation of murine embryonal carcinoma P19 cells
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DOI：
10.1111/j.1365-2443.2011.01525.x
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发表时间：
2011-07-01
期刊：
影响因子：
2.1
通讯作者：
Murakami, Yoshinori
中科院分区：
文献类型：
--
作者：
Ito, Takeshi;Williams-Nate, Yuko;Murakami, Yoshinori
CADM 1是一种多功能细胞粘附分子，主要在神经系统、睾丸和肺中表达。视黄酸（RA）诱导小鼠胚胎癌P19细胞神经分化过程中Cadm 1基因的表达。在这里，我们表明，使用RNAi抑制CADM 1表达干扰了P19细胞聚集，并减少了RA治疗后表达MAP 2的细胞群。未聚集的P19细胞未分化为神经元，表明CADM 1参与了P19在体外的聚集体形成和神经元分化。CADM 1启动子的一系列缺失突变体的荧光素酶测定将RA响应性顺式作用元件定位于翻译起始位点上游的约90-bp片段。该元件含有转录因子Sp1的推定结合位点，命名为Sp1-binding site-1（Sp1 BS-1）。Sp1 BS-1和相邻的Sp1结合位点（Sp1 BS-2和Sp1 BS-3）显示增强的转录活性的RA。此外，染色质免疫沉淀显示RA受体（RAR）α与含有Sp1 BS-1的DNA片段相关，而使用siRNA抑制RAR α表达降低了CADM 1启动子对RA的反应性。这些结果表明，Sp1在RA诱导的CADM 1表达中起着关键作用，可能通过与P19神经分化中的RAR α相互作用。
CADM1 is a multifunctional cell adhesion molecule expressed predominantly in the nerve system, testis and lung. The expression of the Cadm1 gene is induced during the neural differentiation of murine embryonal carcinoma P19 cells by treatment with retinoic acid (RA). Here, we show that the suppression of CADM1 expression using RNAi interfered with P19 cell aggregation and reduced cell populations expressing MAP2 after RA treatment. Nonaggregated P19 cells were not differentiated into neurons, suggesting that CADM1 participates in the aggregate formation and neuronal differentiation of P19 in vitro. A luciferase assay of a series of deletion mutants of the CADM1 promoter localized an RA-responsive cis-acting element to an approximately 90-bp fragment upstream of the translational start site. This element contains a putative binding site for transcription factor Sp1, named Sp1-binding site-1 (Sp1BS-1). Sp1BS-1 and adjacent Sp1-binding sites (Sp1BS-2 and Sp1BS-3) showed enhanced transcriptional activity by RA. Moreover, a chromatin immunoprecipitation showed that RA receptor (RAR)alpha was associated with a DNA fragment containing Sp1BS-1, whereas suppression of RAR alpha expression using siRNA reduced the responsiveness of the CADM1 promoter to RA. These results suggest that Sp1 plays a critical role in RA-induced CADM1 expression through possible interaction with RAR alpha in the neural differentiation of P19.