文章基本信息

标题：The Arabidopsis double-stranded RNA-binding protein HYL1 plays a role in microRNA-mediated gene regulation
本地全文：下载
作者：Meng-Hsuan Han ; Saiprasad Goud ; Liang Song 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2004
卷号：101
期号：4
页码：1093-1098
DOI：10.1073/pnas.0307969100
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The Arabidopsis HYL1 gene encodes a nuclear double-stranded RNA-binding protein. A knockout mutation of the hyl1 gene is recessive and pleiotropic, causing developmental abnormalities, increasing sensitivity to abscisic acid, and reducing sensitivity to auxin and cytokinin. We report that levels of several microRNAs (miRNAs; miR159, -167, and -171) are reduced in homozygous mutant plants, and levels of two of three tested target mRNAs are elevated. Conversely, the miRNA levels are elevated in plants expressing a HYL1 cDNA from a strong promoter, and the corresponding target RNAs are reduced. These changes result from alterations in the stability of the target RNAs. However, double-stranded RNA-induced posttranscriptional gene silencing is unaffected by the hyl1 mutation. One-third to one-half of the cellular HYL1 protein is in a macromolecular complex, and a GFP-HYL1 fusion protein is found predominantly in the nucleus, although it is observed in both nucleus and cytoplasm in some cells. Within nuclei, HYL1 is associated with subnuclear bodies and ring-like structures. These observations provide evidence that the HYL1 protein is part of a nuclear macromolecular complex that is involved in miRNA-mediated gene regulation. Because hyl1 mutants show marked abnormalities in hormone responses, these results further suggest that miRNA-mediated changes in mRNA stability play a vital role in plant hormone signaling.