The Ubiquitin E3 Ligase PUB17 Positively Regulates Immunity by Targeting a Negative Regulator, KH17, for Degradation  

作　　者：Hazel McLellan Kai Chen Qin He Xintong Wu Petra C.Boevink Zhendong Tian Paul R.J.Birch 

机构地区：[1]Division of Plant Science,School of Life Science,University of Dundee(at JHI),Invergowrie,Dundee DD25DA,UK [2]Key Laboratory of Horticultural Plant Biology(HZAU),Ministry of Education,Key Laboratory of Potato Biology and Biotechnology(HZAU),Ministry of Agriculture and Rural Affairs,Huazhong Agricultural University,Wuhan,Hubei 430070,China [3]Cell and Molecular Science,James Hutton Institute,Invergowrie,Dundee DD25DA,UK

出　　处：《Plant Communications》2020年第4期75-86,共12页植物通讯（英文）

基　　金：support from the Biotechnology and Biological Sciences Research Council(BBSRC)grants BB/P020569/1,BB/N009967/1,and BB/L026880/1;the Scottish Government Rural and Environment Science and Analytical Services Division(RESAS);supported by funding from The National Natural Science Foundation of China(grants 31761143007,31471550).

摘　　要：Ubiquitination is a post-translational modification that regulates many processes in plants.Several ubiquitin E3 ligases act as either positive or negative regulators of immunity by promoting the degradation of different substrates.StPUB17 is an E3 ligase that has previously been shown to positively regulate immunity to bacteria,fungi and oomycetes,including the late blight pathogen Phytophthora infestans.Silencing of StPUB17 promotes pathogen colonization and attenuates Cf4/avr4 cell death.Using yeast-2-hybrid and co-immunoprecipitation we identified the putative K-homology(KH)RNA-binding protein(RBP),StKH17,as a candidate substrate for degradation by StPUB17.StKH17 acts as a negative regulator of immunity that promotes P.infestans infection and suppresses specific immune pathways.A KH RBP domain mutant of StKH17(StKH17GDDG)is no longer able to negatively regulate immunity,indicating that RNA binding is likely required for StKH17 function.As StPUB17 is a known target of the ubiquitin E3 ligase,StPOB1,we reveal an additional step in an E3 ligase regulatory cascade that controls plant defense.

关 键 词：OOMYCETE plant disease late blight E3 ligase KH RNA-binding protein 

分 类 号：S43[农业科学—农业昆虫与害虫防治]