Specific interactions between Dicer-like proteins and HYL1/DRB-family dsRNA-binding proteins in Arabidopsis thaliana
Specific interactions between Dicer-like proteins and HYL1/DRB-family dsRNA-binding proteins in Arabidopsis thaliana
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DOI：
10.1007/s11103-004-6853-5
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发表时间：
2005-01-01
影响因子：
5.1
通讯作者：
Fukuhara, T
中科院分区：
文献类型：
--
作者：
Hiraguri, A;Itoh, R;Fukuhara, T
特异性结合双链RNA （dsRNA）的蛋白质参与细胞信号事件和基因表达的调控，并以保守的dsRNA结合基元（dsRBM）为特征。在这里，我们报告了9个这样的基因产物的生化特性，每个都含有一个或两个dsrbm: 4个arabidopsisdicer样蛋白（DCL1-4）， arabidopsisishyl1及其4个同源物（DRB2, DRB4， DRB5和OsDRB1）。DCL1、DCL3、HYL1及4个HYL1同源物均表现出显著的dsrna结合活性，表明这些蛋白参与RNA代谢。含有dsrbm的蛋白（dsrbp）的dsrbm也作为蛋白质相互作用域，同源和异源二聚化对这些蛋白的生物学功能至关重要。我们发现DRB4与DCL4特异性相互作用，而HYL1与DCL1的相互作用最强。这些结果表明，每个HYL1/DRB家族蛋白与四个dicer样蛋白中的一个特定伴侣相互作用。利用GFP融合蛋白进行定位研究表明，DCL1、DCL4、HYL1和DRB4定位于细胞核，而DRB2则存在于细胞质中。HYL1、DRB4、DCL1和DCL4的亚细胞定位进一步强化了HYL1和DCL1、DRB4和DCL4作为复合物存在的概念。目前的数据表明，HYL1/DRB蛋白家族的每个成员都可以通过体内与Dicer样蛋白的异源二聚化单独调节Dicer功能。
Proteins that specifically bind double-stranded RNA (dsRNA) are involved in the regulation of cellular signaling events and gene expression, and are characterized by a conserved dsRNA-binding motif (dsRBM). Here we report the biochemical properties of nine such gene products, each containing one or two dsRBMs: four ArabidopsisDicer-like proteins (DCL1-4), ArabidopsisHYL1 and four of its homologs (DRB2, DRB4, DRB5 and OsDRB1). DCL1, DCL3, HYL1 and the four HYL1 homologs exhibit significant dsRNA-binding activity, indicating that these proteins are involved in RNA metabolism. The dsRBMs from dsRBM-containing proteins (dsRBPs) also function as a protein-protein interaction domain and homo- and heterodimerization are essential for biological functioning of these proteins. We show that DRB4 interacts specifically with DCL4, and HYL1 most strongly interacts with DCL1. These results indicate that each HYL1/DRB family protein interacts with one specific partner among the four Dicer-like proteins. Localization studies using GFP fusion proteins demonstrate that DCL1, DCL4, HYL1 and DRB4 localize in the nucleus, while DRB2 is present in the cytoplasm. Subcellular localizations of HYL1, DRB4, DCL1 and DCL4 further strengthen the notion that HYL1 and DCL1, and DRB4 and DCL4, exist as complexes. The presented data suggest that each member of the HYL1/DRB protein family may individually modulate Dicer function through heterodimerization with a Dicer-like protein in vivo.