Human Dicer C-terminus functions as a 5-lipoxygenase binding domain
Human Dicer C-terminus functions as a 5-lipoxygenase binding domain
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DOI：
10.1016/j.bbagrm.2008.10.002
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发表时间：
2009-02-01
影响因子：
4.7
通讯作者：
Provost, Patrick
中科院分区：
文献类型：
--
作者：
Dincbas-Renqvist, Vildan;Pepin, Genevieve;Provost, Patrick
DICER是一种多结构域核糖核酸酶III，参与绝大多数真核生物中microRNAs(MiRNAs)的生物发生。在人类中，DICER已被证明通过其N-末端结构域与细胞蛋白相互作用。在这里，我们展示了在体外和在培养的人类细胞中，DICER C末端与5-脂氧合酶(5LO)相互作用的能力，5LO是一种参与炎症介质生物合成的酶。酵母菌双杂交和GST结合分析确定了DICER最小的5-脂氧合酶结合域(5LObd)，其C末端140个氨基酸组成了双链RNA(DsRNA)结合域(DsRBD)。当5LO中的色氨酸残基13、75和102被Ala取代后，DICER 5LObd-5LO的结合被破坏，这表明DICER 5LObd可能通过其N端C2样结构域识别5LO。然而，在体外，含有催化活性的5LObd的Disher片段可以增强5LO的酶活性，而人的5LO则改变了Dird的miRNA前体加工活性。我们的结果提供了miRNA介导的基因表达调控与炎症之间的联系，我们的结果表明，表达这种脂氧合酶的白细胞和癌细胞中miRNAs的形成可能受到5LO的调控。(C)2008爱思唯尔B.V.保留所有权利。
Dicer is a multidomain ribonuclease III enzyme involved in the biogenesis of microRNAs (miRNAs) in the vast majority of eukaryotes. In human, Dicer has been shown to interact with cellular proteins via its N-terminal domain. Here, we demonstrate the ability of Dicer C-terminus to interact with 5-lipoxygenase (5LO), an enzyme involved in the biosynthesis of inflammatory mediators, in vitro and in cultured human cells. Yeast two-hybrid and GST binding assays delineated the smallest 5-lipoxygenase binding domain (5LObd) of Dicer to its C-terminal 140 amino acids comprising the double-stranded RNA (dsRNA) binding domain (dsRBD). The Dicer 5LObd-5LO association was disrupted upon Ala substitution of Trp residues 13, 75 and 102 in 5LO, suggesting that the Dicer 5LObd may recognize 5LO via its N-terminal C2-like domain. Whereas a catalytically active 5LObd-containing Dicer fragment was found to enhance 5LO enzymatic activity in vitro, human 5LO modified the miRNA precursor processing activity of Dicer. Providing a link between miRNA-mediated regulation of gene expression and inflammation, our results suggest that the formation of miRNAs may be regulated by 5LO in leukocytes and cancer cells expressing this lipoxygenase. (C) 2008 Elsevier B.V. All rights reserved.