Transporter-Mediated Nuclear Entry of Jasmonoyl-lsoleucine Is Essential for Jasmonate Signaling  

作　　者：Qingqing Li Jian Zheng Shuaizhang Li Guanrong Huang Stephen J. Skilling Lijian Wang Ling Li Mengya Li Lixing Yuan Pei Liu 

机构地区：[1]Department of Ecology [2]Department of Plant Nutrition College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, P. R. China

出　　处：《Molecular Plant》2017年第5期695-708,共14页分子植物（英文版）

摘　　要：To control gene expression by directly responding to hormone concentrations, both animal and plant cells have exploited comparable mechanisms to sense small-molecule hormones in nucleus. Whether nuclear entry of these hormones is actively transported or passively diffused, as conventionally postulated, through the nuclear pore complex, remains enigmatic. Here, we identified and characterized a jasmonate transporter in Arabidopsis thaliana, AtJAT1/AtABCG16, which exhibits an unexpected dual localization at the nuclear envelope and plasma membrane. We show that AtJAT1/AtABCG16 controls the cytoplasmic and nuclear partition of jasmonate phytohormones by mediating both cellular efflux of jasmonic acid （JA） and nuclear influx of jasmonoyl-isoleucine （JA-Ile）, and is essential for maintaining a critical nuclear JA-Ile concentration to activate JA signaling. These results illustrate that transporter-mediated nuclear entry of small hormone molecules is a new mechanism to regulate nuclear hormone signaling. Our findings provide an avenue to develop pharmaceutical agents targeting the nuclear entry of small molecules.To control gene expression by directly responding to hormone concentrations, both animal and plant cells have exploited comparable mechanisms to sense small-molecule hormones in nucleus. Whether nuclear entry of these hormones is actively transported or passively diffused, as conventionally postulated, through the nuclear pore complex, remains enigmatic. Here, we identified and characterized a jasmonate transporter in Arabidopsis thaliana, AtJAT1/AtABCG16, which exhibits an unexpected dual localization at the nuclear envelope and plasma membrane. We show that AtJAT1/AtABCG16 controls the cytoplasmic and nuclear partition of jasmonate phytohormones by mediating both cellular efflux of jasmonic acid （JA） and nuclear influx of jasmonoyl-isoleucine （JA-Ile）, and is essential for maintaining a critical nuclear JA-Ile concentration to activate JA signaling. These results illustrate that transporter-mediated nuclear entry of small hormone molecules is a new mechanism to regulate nuclear hormone signaling. Our findings provide an avenue to develop pharmaceutical agents targeting the nuclear entry of small molecules.

关 键 词：jasmonate transporter jasmonic acid jasmonoyl-isoleucine nuclear import AtJAT1/AtABCG16 

分 类 号：Q94[生物学—植物学]