Membrane-localized ubiquitin ligase ATL15 functions in sugar-responsive growth regulation in Arabidopsis
Membrane-localized ubiquitin ligase ATL15 functions in sugar-responsive growth regulation in Arabidopsis
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DOI：
10.1016/j.bbrc.2017.07.028
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发表时间：
2017-09-09
影响因子：
3.1
通讯作者：
Yamaguchi, Junji
中科院分区：
文献类型：
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作者：
Aoyama, Shoki;Terada, Saki;Yamaguchi, Junji
泛素连接酶通过调节特定泛素化靶点的蛋白质功能，在调节多种细胞过程中发挥重要作用。拟南芥毒素蛋白家族(ATL)是一组植物特有的环型泛素连接酶，通过N-末端跨膜区定位于细胞膜。到目前为止，已在拟南芥基因组中鉴定出91种ATL亚型，其中有几种ATL被报道参与调节植物对环境胁迫的反应。然而，大多数ATL的功能仍不清楚。本研究通过对转录组数据库的分析，确定ATL15是拟南芥中一个糖响应的ATL基因。在糖的存在下，ATL15的表达迅速下调。ATL15蛋白在体外具有泛素连接酶活性，并定位于质膜和内膜室。进一步的遗传分析表明，atI15基因敲除突变体对高糖浓度不敏感，而ATL15过表达则抑制植物生长。此外，在AT115基因敲除突变体和ATL15过表达基因中，内源葡萄糖和淀粉的含量也受到交互影响。这些结果表明，ATL15蛋白作为一种膜定位的泛素连接酶在拟南芥中调节糖反应植物的生长起着重要的作用。(C)2017 Elsevier Inc.保留所有权利。
Ubiquitin ligases play important roles in regulating various cellular processes by modulating the protein function of specific ubiquitination targets. The Arabidopsis Toxicos en Levadura (ATL) family is a group of plant-specific RING-type ubiquitin ligases that localize to membranes via their N-terminal transmembrane-like domains. To date, 91 ATL isoforms have been identified in the Arabidopsis genome, with several ATLs reported to be involved in regulating plant responses to environmental stresses. However, the functions of most ATLs remain unknown. This study, involving transcriptome database analysis, identifies ATL15 as a sugar responsive ATL gene in Arabidopsis. ATL15 expression was rapidly down-regulated in the presence of sugar. The ATL15 protein showed ubiquitin ligase activity in vitro and localized to plasma membrane and endomembrane compartments. Further genetic analyses demonstrated that the atI15 knockout mutants are insensitive to high glucose concentrations, whereas ATL15 overexpression depresses plant growth. In addition, endogenous glucose and starch amounts were reciprocally affected in the at115 knockout mutants and the ATL15 overexpressors. These results suggest that ATL15 protein plays a significant role as a membrane-localized ubiquitin ligase that regulates sugar responsive plant growth in Arabidopsis. (C) 2017 Elsevier Inc. All rights reserved.