The SINA E3 Ligase OsDIS1 Negatively Regulates Drought Response in Rice
The SINA E3 Ligase OsDIS1 Negatively Regulates Drought Response in Rice
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SINA E3 连接酶 OsDIS1 负调控水稻的干旱反应
DOI：
10.1104/pp.111.180893
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发表时间：
2011-09-01
期刊：
影响因子：
7.4
通讯作者：
Wang, Guo-Liang
中科院分区：
文献类型：
--
作者：
Ning, Yuese;Jantasuriyarat, Chachawan;Wang, Guo-Liang
泛素调节的蛋白质降解是植物中控制广泛生物学过程的重要调节机制。OsDIS 1（Oryza sativa drough-induced SINA protein 1）是一种C3 HC 4环指E3连接酶，在水稻干旱胁迫信号转导中起重要作用。sativa）。干旱处理上调了OsDIS 1的表达。体外泛素化实验表明OsDIS 1具有E3泛素连接酶活性，其RING指的保守区域是该活性所必需的。在烟草叶片和水稻原生质体中的瞬时表达实验表明OsDIS 1主要定位于细胞核中。过量表达OsDIS 1降低了转基因水稻的耐旱性，而RNA干扰沉默OsDIS 1则增强了转基因水稻的耐旱性。基因芯片分析表明，在正常和干旱条件下，OsDIS 1过表达植株中大量的干旱响应基因被诱导或抑制。酵母双杂交筛选结果表明OsDIS 1与OsNek 6（O. sativa NIMA相关激酶6），一种微管蛋白复合物相关的丝氨酸/苏氨酸蛋白激酶。在N.本塞姆氏藻叶片的研究表明OsNek 6被OsDIS 1通过26 S蛋白酶体依赖性途径降解，并且这种降解被OsDIS 1（H71 Y）突变消除，这是其E3连接酶活性所必需的。总之，这些结果表明，OsDIS 1起着负面作用，在干旱胁迫耐受性通过转录调控不同的胁迫相关基因，并可能通过翻译后调控OsNek 6在水稻。
Ubiquitin-regulated protein degradation is a critical regulatory mechanism that controls a wide range of biological processes in plants. Here, we report that OsDIS1 (for Oryza sativa drought-induced SINA protein 1), a C3HC4 RING finger E3 ligase, is involved in drought-stress signal transduction in rice (O. sativa). The expression of OsDIS1 was up-regulated by drought treatment. In vitro ubiquitination assays showed that OsDIS1 possessed E3 ubiquitin ligase activity and that the conserved region of the RING finger was required for the activity. Transient expression assays in Nicotiana benthamiana leaves and rice protoplasts indicated that OsDIS1 was localized predominantly in the nucleus. Overexpression of OsDIS1 reduced drought tolerance in transgenic rice plants, while RNA interference silencing of OsDIS1 enhanced drought tolerance. Microarray analysis revealed that a large number of drought-responsive genes were induced or suppressed in the OsDIS1 overexpression plants under normal and drought conditions. Yeast two-hybrid screening showed that OsDIS1 interacted with OsNek6 (for O. sativa NIMA-related kinase 6), a tubulin complex-related serine/threonine protein kinase. Coexpression assays in N. benthamiana leaves indicated that OsNek6 was degraded by OsDIS1 via the 26S proteasome-dependent pathway and that this degradation was abolished by the OsDIS1(H71Y) mutation, which is essential for its E3 ligase activity. Together, these results demonstrate that OsDIS1 plays a negative role in drought stress tolerance through transcriptional regulation of diverse stress-related genes and possibly through posttranslational regulation of OsNek6 in rice.