Identification of mRNA binding proteins that regulate the stability of LDL receptor mRNA through AU-rich elements
Identification of mRNA binding proteins that regulate the stability of LDL receptor mRNA through AU-rich elements
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DOI：
10.1194/jlr.m800375-jlr200
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发表时间：
2009-05-01
影响因子：
6.5
通讯作者：
Liu, Jingwen
中科院分区：
文献类型：
--
作者：
Li, Hai;Chen, Wei;Liu, Jingwen
人低密度脂蛋白受体（LDL receptor，LDLR）mRNA的3'非翻译区（3' untranslated region，UTR）含有3个富含AU的元件（AU-rich elements，战神），它们负责mRNA的快速更新并介导小檗碱（BBR）诱导的稳定化。然而，在稳态水平或BBR处理后，参与调节LDLR mRNA稳定性的特异性RNA结合蛋白的特性尚不清楚。通过进行小干扰RNA文库筛选、生物素化RNA下拉、质谱分析和功能测定，我们现在确定异质核核糖核蛋白D（hnRNP D）、hnRNP I和KH型剪接调节蛋白（KSRP）是肝细胞中LDLR mRNA稳定性的关键调节剂。我们发现hnRNP D、I和KSRP与LDLR 3' UTR的战神相互作用具有序列特异性。沉默这些蛋白的表达增加了LDLR mRNA和蛋白水平。我们进一步证明，BBR诱导的mRNA稳定化涉及hnRNP I和KSRP，因为它们的细胞消耗消除了BBR效应，并且BBR处理减少了hnRNP I和KSRP与LDLR mRNA 3' UTR的结合。这些新发现表明LDLR mRNA稳定性受一组ARE结合蛋白（包括hnRNP D、hnRNP I和KSRP）控制。jlr我们的结果表明，干扰使ARE结合蛋白不稳定以与LDLR-ARE基序相互作用的能力可能是通过化合物如BBR和可能的其他化合物调节LDLR表达的机制。Li，H.，W. Chen，Y. Zhou，P. Abidi，O.夏普，W。H.罗宾逊，F. B。Kraemer，and J. Liu.通过富含AU的元件调节LDL受体mRNA稳定性的mRNA结合蛋白的鉴定。J. Lipid Res. 2009. 50：820-831。
The 3' untranslated region (UTR) of human LDL receptor ( LDLR) mRNA contains three AU-rich elements (AREs) responsible for rapid mRNA turnover and mediates the stabilization induced by berberine (BBR). However, the identities of the specific RNA binding proteins involved in the regulation of LDLR mRNA stability at the steady state level or upon BBR treatment are unknown. By conducting small interfering RNA library screenings, biotinylated RNA pull-down, mass spectrometry analysis, and functional assays, we now identify heterogeneous nuclear ribonucleoprotein D ( hnRNP D), hnRNP I, and KH-type splicing regulatory protein (KSRP) as key modulators of LDLR mRNA stability in liver cells. We show that hnRNP D, I, and KSRP interact with AREs of the LDLR 3' UTR with sequence specificity. Silencing the expression of these proteins increased LDLR mRNA and protein levels. We further demonstrate that BBR-induced mRNA stabilization involves hnRNP I and KSRP, as their cellular depletions abolished the BBR effect and BBR treatment reduced the binding of hnRNP I and KSRP to the LDLR mRNA 3' UTR. These new findings demonstrate that LDLR mRNA stability is controlled by a group of ARE binding proteins, including hnRNP D, hnRNP I, and KSRP. jlr Our results suggest that interference with the ability of destabilizing ARE binding proteins to interact with LDLR-ARE motifs is likely a mechanism for regulating LDLR expression by compounds such as BBR and perhaps others.-Li, H., W. Chen, Y. Zhou, P. Abidi, O. Sharpe, W. H. Robinson, F. B. Kraemer, and J. Liu. Identification of mRNA binding proteins that regulate the stability of LDL receptor mRNA through AU-rich elements. J. Lipid Res. 2009. 50: 820-831.