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RUP2 facilitates UVR8 redimerization via two interfaces

Authors :
Lixia Wang
Yidong Wang
Hongfei Chang
Hui Ren
Xinquan Wu
Jia Wen
Zeyuan Guan
Ling Ma
Liang Qiu
Junjie Yan
Delin Zhang
Xi Huang
Ping Yin
Source :
Plant Communications, Vol 4, Iss 1, Pp 100428- (2023)
Publication Year :
2023
Publisher :
Elsevier, 2023.

Abstract

The plant UV-B photoreceptor UV RESISTANCE LOCUS 8 (UVR8) exists as a homodimer in its inactive ground state. Upon UV-B exposure, UVR8 monomerizes and interacts with a downstream key regulator, the CONSTITUTIVE PHOTOMORPHOGENIC 1/SUPPRESSOR OF PHYA (COP1/SPA) E3 ubiquitin ligase complex, to initiate UV-B signaling. Two WD40 proteins, REPRESSOR OF UV-B PHOTOMORPHOGENESIS 1 (RUP1) and RUP2 directly interact with monomeric UVR8 and facilitate UVR8 ground state reversion, completing the UVR8 photocycle. Here, we reconstituted the RUP-mediated UVR8 redimerization process in vitro and reported the structure of the RUP2-UVR8W285A complex (2.0 Å). RUP2 and UVR8W285A formed a heterodimer via two distinct interfaces, designated Interface 1 and 2. The previously characterized Interface 1 is found between the RUP2 WD40 domain and the UVR8 C27 subregion. The newly identified Interface 2 is formed through interactions between the RUP2 WD40 domain and the UVR8 core domain. Disruption of Interface 2 impaired UV-B induced photomorphogenic development in Arabidopsis thaliana. Further biochemical analysis indicated that both interfaces are important for RUP2-UVR8 interactions and RUP2-mediated facilitation of UVR8 redimerization. Our findings suggest that the two-interface-interaction mode is adopted by both RUP2 and COP1 when they interact with UVR8, marking a step forward in understanding the molecular basis that underpins the interactions between UVR8 and its photocycle regulators.

Details

Language :
English
ISSN :
25903462
Volume :
4
Issue :
1
Database :
Directory of Open Access Journals
Journal :
Plant Communications
Publication Type :
Academic Journal
Accession number :
edsdoj.626f5d9bc24a4dcd9c900bf25415968a
Document Type :
article
Full Text :
https://doi.org/10.1016/j.xplc.2022.100428