Rapid, nongenomic actions of retinoic acid on phosphatidylinositol-3-kinase signaling pathway mediated by the retinoic acid receptor
Rapid, nongenomic actions of retinoic acid on phosphatidylinositol-3-kinase signaling pathway mediated by the retinoic acid receptor
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DOI：
10.1210/me.2007-0062
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发表时间：
2007-10-01
影响因子：
--
通讯作者：
Barettino, Domingo
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文献类型：
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作者：
Masia, Susana;Alvarez, Susana;Barettino, Domingo
视黄酸（RA）处理SH-SY 5 Y神经母细胞瘤细胞导致磷脂酰肌醇-3-激酶（PI 3 K）信号通路的激活，并且这种激活是RA诱导分化所必需的。在这里，我们表明，RA激活PI 3 K和ERK 1/ 2 MAPK信号通路通过一个快速的，非基因组机制，不需要新的基因转录或新合成的蛋白质。基于小鼠胚胎成纤维细胞-RAR（α-β-γ）（L-/L-）无效细胞的激活、丧失和获得功能实验的药理学特征，以及配体RAR和PI 3 K活性之间的物理关联，RA对PI 3 K的激活似乎涉及经典的核受体视黄酸受体（RAR）。RAR与PI 3 K的两个亚基的关联受到配体的差异调节。在SH-SY 5 Y细胞中进行的免疫沉淀实验显示RAR α和PI 3 K的调节亚基p85之间稳定的结合，与RA的存在无关。与此相反，配体管理增加了协会的p110，催化亚基的PI 3 K，这个复杂的。RAR的细胞内定位被证明与PI 3 K激活有关。将c-Src肉豆蔻基化结构域融合至RAR α的N末端的嵌合RAR（Myr-RAR α）靶向质膜。将Myr-RAR α转染至小鼠胚胎成纤维细胞- RAR（α β γ）（L-/L-）无效细胞和COS- 7细胞导致PI 3 K信号传导途径的强烈激活，尽管两者都在RA不存在以及存在的情况下.我们的研究结果支持一种机制，其中配体结合RAR将发挥重要作用的组装和细胞内的位置的信号复合物，涉及RAR和PI 3 K的亚基。
Retinoic acid ( RA) treatment of SH- SY5Y neuroblastoma cells results in activation of phosphatidylinositol-3- kinase ( PI3K) signaling pathway, and this activation is required for RA- induced differentiation. Here we show that RA activates PI3K and ERK1/ 2 MAPK signaling pathways through a rapid, nongenomic mechanism that does not require new gene transcription or newly synthesized proteins. Activation of PI3K by RA appears to involve the classical nuclear receptor, retinoic acid receptor ( RAR), on the basis of the pharmacological profile of the activation, loss, and gain of function experiments with mouse embryo fibroblast-RAR(alpha beta gamma)(L-/L-) null cells, and the physical association between liganded RAR and PI3K activity. The association of RAR with the two subunits of PI3K was differentially regulated by the ligand. Immunoprecipitation experiments performed in SH- SY5Y cells showed stable association between RAR alpha and p85, the regulatory subunit of PI3K, independently of the presence of RA. In contrast, ligand administration increased the association of p110, the catalytic subunit of PI3K, to this complex. The intracellular localization of RAR proved to be relevant for PI3K activation. A chimerical RAR fusing c- Src myristylation domain to the N terminus of RAR alpha ( Myr-RAR alpha) was targeted to plasma membrane. Transfection of Myr- RAR alpha to mouse embryo fibroblast- RAR(alpha beta gamma)(L-/L-) null cells and COS- 7 cells results in strong activation of the PI3K signaling pathway, although both in the absence as well in the presence of RA. Our results support a mechanism in which ligand binding to RAR would play a major role in the assembly and intracellular location of a signaling complex involving RAR and the subunits of PI3K.