Destabilization of strigolactone receptor DWARF14 by binding of ligand and E3-1igase signaling effector DWARF3  

作　　者：Li-Hua Zhao X Edward Zhou Wei Yi Zhongshan Wu Yue Liu Yanyong Kang Li Hou Parker W de Waal Suling Li Yi Jiang Adrian Scaffidi Gavin R Flematti Steven M Smith Vinh Q Lam Patrick R Griffin YonghongWang Jiayang Li Karsten Melcher H Eric Xu 

机构地区：[1]VARI-SIMM Center, Center for Structure and Function of Drug Targets, Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203,China [2]The Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai 200241 [3]Laboratory of Structural Sciences and Laboratory of Structural Biology and Biochemistry, Van Andel Research Institute, Grand Rapids, Michigan, USA [4]Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Hubei 430074, China [5]School of Chemistry and Biochemistry, The University of Western Australia, Crawley, WA 6009, Australia [6]School of Biological Sciences, University of Tasmania Hobart, Hobart, TAS 7001 Australia [7]State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China [8]Department of Molecular Therapeutics, Translational Research Institute, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, USA

出　　处：《Cell Research》2015年第11期1219-1236,共18页细胞研究（英文版）

基　　金：the Van Andel Research institute, Amway （China）, the National Natural Science Foundation of China （NSFC 31300245 and NSFC 91217311）, the Ministry of Science and Technology of China （2012ZX09301001, 2012CB910403,2013CB910600, XDB08020303, and 2013ZX09507001）, and the National Institute of Health （USA; DK071662 to HEX, and GM102545 and GM104212 to KM）. We thank staff members of the Life Science Collaborative Access Team of the Advanced Pho- ton Source （APS） for assistance in data collection at the beam lines of sector 21, which is in part funded by the Michigan Economic Development Corporation and the Michigan Technology Tri-Cor- ridor （085P1000817）. Use of APS was supported by the Office of Science of the US Department of Energy, under contract no DE- AC02-06CH 11357.

摘　　要：Strigolactones （SLs） are endogenous hormones and exuded signaling molecules in plant responses to low levels of mineral nutrients. Key mediators of the SL signaling pathway in rice include the a/p-fold hydrolase DWARF 14 （D14） and the F-box component DWARF 3 （D3） of the ubiquitin ligase SCFD3 that mediate ligand-dependent degradation of downstream signaling repressors. One perplexing feature is that D14 not only functions as the SL receptor but is also an active enzyme that slowly hydrolyzes diverse natural and synthetic SLs including GR24, preventing the crystal- lization of a binary complex of D14 with an intact SL as well as the ternary D14/SL/D3 complex. Here we overcome these barriers to derive a structural model of D14 bound to intact GR24 and identify the interface that is required for GR24-mediated D14-D3 interaction. The mode of GR24-mediated signaling, including ligand recognition, hydrolysis by D14, and ligand-mediated D14-D3 interaction, is conserved in structurally diverse SLs. More importantly, D14 is destabilized upon the binding of ligands and D3, thus revealing an unusual mechanism of SL recognition and sig- naling, in which the hormone, the receptor, and the downstream effectors are systematically destabilized during the signal transduction process.

关 键 词：STRIGOLACTONES D14 D3 GR24 receptor/co-receptor 

分 类 号：Q26[生物学—细胞生物学] Q578