Propagation strategy of the double-stranded RNA replicon symbiotically in a rice cell.

我们已经从许多作物和野生植物中发现了各种各样的双链RNA（dsRNA）。国际病毒分类学委员会（ICTV）最近承认内多核糖核酸病毒属（Endornavirus）是一个新的属，该属在水稻和蚕豆中含有大的质粒样dsRNA复制体（约14 ~ 17 kbp）。然而，核内RNA病毒的序列信息有限，只有四个dsRNA被完全测序。从大麦（Hordeum vulgare）、菜豆（Phaseolus vulgaris）、甜瓜（Cucumis梅洛）、葫芦（Lagenaria siceraria）、马拉巴尔菠菜（Basella alba）、海草（Zostera marina）和真菌Helicobasidium mompa中的大dsRNA获得RNA依赖性RNA聚合酶区域的部分核苷酸序列。对这7个dsRNA与已知的内核病毒和单链RNA病毒的系统发育分析表明，这些dsRNA是广泛分布于植物和真菌中的内核病毒的新成员。这些双链RNA及其同源序列之间的系统发育关系， ...更多信息 我们比较了携带和不携带dsRNA的水稻培养细胞的总蛋白含量，发现了一些差异。这些结果表明，植物细胞中应该存在一种能够调节dsRNA复制子的宿主蛋白。我们推测宿主蛋白可以特异性结合dsRNA，并且该蛋白应该具有一个保守的dsRNA结合基序（dsRBM）。我们的特点是生物化学10拟南芥dsRBM含有蛋白质。两个Dicer样蛋白（DCL 1和DCL 3），HYL 1/DRB 1和三个HYL 1同源物显示出显着的dsRNA结合活性。此外，我们发现DRB 4与DCL 4特异性相互作用，而HYL 1与DCL 1的相互作用最强。这些结果表明，每个HYL 1/DRB家族蛋白与四个Dicer样蛋白中的一个特异性伴侣相互作用。所呈现的数据表明，HYL 1/DRB蛋白家族的每个成员可以通过体内与Dicer样蛋白的异源二聚化来单独调节Dicer功能。少

We have found various double-stranded RNAs(dsRNAs) from many species of crops and wild plants. The International Committee on Taxonomy of Viruses(ICTV) recently accepted Endornavirus as a new genus, consisting of large (about 14 to 17 kbp) plasmid-like dsRNA replions in rice and broad bean. However, the sequence information of endornaviruses is limited and only four dsRNAs have been sequenced entirely. Partial nucleotide sequences of RNA-dependent RNA polymerase regions were obtained from large dsRNAs in barley (Hordeum vulgare), kidney bean (Phaseolus vulgaris), melon (Cucumis melo), bottle gourd (Lagenaria siceraria), Malabar spinach (Basella alba), seagrass (Zostera marina), and the fungus Helicobasidium mompa. Phylogenetic analyses of these seven dsRNAs with known endornaviruses and single-stranded RNA viruses indicate that these dsRNAs are new members of Endornavirus that are widely distributed over plants and fungi. The phylogenetic relationships between these dsRNAs and their ho … More st plants suggest that ancestors of dsRNA replicons were horizontally transmissible.We compared total protein contents between dsRNA-carrier and dsRNA-free rice cultured cells and detected some differences. These results suggest that a host protein, which can regulate the dsRNA replicons, should exist in a plant cell. We presumed that the host proteins could bind dsRNA specifically and this protein should have a conserved dsRNA-binding motif (dsRBM). We characterized biochemically ten Arabidopsis dsRBM-containing proteins. Two Dicer-like proteins (DCL1 and DCL3), HYL1/DRB1 and the three HYL1 homologs exhibit significant dsRNA-binding activity. Furthermore, 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. 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. Less