Volume 25, No 11, Nov 2015

ISSN: 1001-0602 
EISSN: 1748-7838 2018 
impact factor 17.848* 
(Clarivate Analytics, 2019)

Volume 25 Issue 11, November 2015: 1219-1236

ORIGINAL ARTICLES

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

Li-Hua Zhao1,2,*, X Edward Zhou3,*, Wei Yi1,*, Zhongshan Wu1,3,4, Yue Liu1, Yanyong Kang3, Li Hou1,3, Parker W de Waal3, Suling Li1, Yi Jiang1, Adrian Scaffidi5, Gavin R Flematti5, Steven M Smith5,6,7, Vinh Q Lam8, Patrick R Griffin8, Yonghong Wang7, Jiayang Li7, Karsten Melcher1,3 and H Eric Xu1,3

¹VARI-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
²The Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai 200241, China
³Laboratory of Structural Sciences and Laboratory of Structural Biology and Biochemistry, Van Andel Research Institute, Grand Rapids, Michigan, USA
⁴Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
⁵School of Chemistry and Biochemistry, The University of Western Australia, Crawley, WA 6009, Australia
⁶School of Biological Sciences, University of Tasmania Hobart, Hobart, TAS 7001 Australia
⁷State 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
⁸Department of Molecular Therapeutics, Translational Research Institute, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, USA Correspondence: Karsten Melcher, E-mail: Karsten.Melcher@vai.org; H Eric Xu,(Eric.Xu@vai.org)

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 α/β-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 crystallization 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 signaling, in which the hormone, the receptor, and the downstream effectors are systematically destabilized during the signal transduction process.

10.1038/cr.2015.122

FULL TEXT | PDF

Browse 2043