Nguyen-Chi Mai, Morello Dominique
Université de Toulouse, CBD, UMR, 5547, CNRS, IFR 109, 118, route de Narbonne, 31062 Toulouse, France.
Med Sci (Paris). 2008 Mar;24(3):290-6. doi: 10.1051/medsci/2008243290.
Almost 10% of mammalian coding mRNAs contain in their 3' untranslated region a sequence rich in adenine and uridine residues known as AU-rich element (ARE). Many of them encode oncogenes (for instance c-Myc and c-Fos), cell cycle regulators (cyclin D1, A1, B1), cytokines (TNFalpha, IL2) and growth factors (GM-CSF) which are overexpressed in cancer or inflammatory diseases due to increased mRNA stability and/or translation. AREs are recognized by a group of proteins, collectively called AUBPs which display various functions. For instance, HuR/ELAV is mainly known to protect ARE-containing mRNAs from degradation, while AUF1, TTP and KSRP act to destabilize their bound target mRNAs and TIA/TIAR to inhibit their translation. Alterations in ARE sequences or AUBP abundance, cellular localization or activity due to post-translational modifications such as phosphorylation can promote or enhance malignancy or perturb immune homeostasis. Here, c-myc and TNFalpha are chosen as examples to illustrate how altered 3' UTR gene regulation impacts on pathologies.
近10%的哺乳动物编码mRNA在其3'非翻译区含有一段富含腺嘌呤和尿嘧啶残基的序列,称为富含AU元件(ARE)。其中许多编码癌基因(如c-Myc和c-Fos)、细胞周期调节因子(细胞周期蛋白D1、A1、B1)、细胞因子(TNFα、IL2)和生长因子(GM-CSF),由于mRNA稳定性增加和/或翻译增加,它们在癌症或炎症性疾病中过表达。ARE被一组蛋白质识别,这些蛋白质统称为AUBP,具有多种功能。例如,HuR/ELAV主要是保护含ARE的mRNA不被降解,而AUF1、TTP和KSRP则使它们结合的靶mRNA不稳定,TIA/TIAR则抑制其翻译。由于翻译后修饰(如磷酸化)导致的ARE序列或AUBP丰度、细胞定位或活性的改变,可促进或增强恶性肿瘤或扰乱免疫稳态。在这里,选择c-myc和TNFα作为例子来说明3'UTR基因调控改变如何影响病理状态。