PMID- 23277547 OWN - NLM STAT- MEDLINE DCOM- 20130314 LR - 20211021 IS - 1091-6490 (Electronic) IS - 0027-8424 (Print) IS - 0027-8424 (Linking) VI - 110 IP - 3 DP - 2013 Jan 15 TI - Reversion of the Arabidopsis UV-B photoreceptor UVR8 to the homodimeric ground state. PG - 1113-8 LID - 10.1073/pnas.1214237110 [doi] AB - Plants require the UV-B photoreceptor UV resistance locus 8 (UVR8) for acclimation and survival in sunlight. Upon UV-B perception, UVR8 switches instantaneously from a homodimeric to monomeric configuration, which leads to interaction with the key signaling protein constitutively photomorphogenic 1 (COP1) and induction of UV-B-protective responses. Here, we show that UVR8 monomerization is reversible in vivo, restoring the homodimeric ground state. We also demonstrate that the UVR8-interacting proteins repressor of UV-B photomorphogenesis (RUP)1 and RUP2 mediate UVR8 redimerization independently of COP1. UVR8 redimerization consequently disrupts the UVR8-COP1 interaction, which halts signaling. Our results identify a key role of RUP1- and RUP2-mediated UVR8 redimerization in photoreceptor inactivation, a crucial process that regenerates reactivatable UVR8 homodimers. FAU - Heijde, Marc AU - Heijde M AD - Department of Botany and Plant Biology, Sciences III, University of Geneva, CH-1211 Geneva 4, Switzerland. FAU - Ulm, Roman AU - Ulm R LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20121231 PL - United States TA - Proc Natl Acad Sci U S A JT - Proceedings of the National Academy of Sciences of the United States of America JID - 7505876 RN - 0 (Arabidopsis Proteins) RN - 0 (Chromosomal Proteins, Non-Histone) RN - 0 (Photoreceptors, Plant) RN - 0 (Repressor Proteins) RN - 0 (Uvr8 protein, Arabidopsis) RN - EC 2.3.2.27 (AT2G32950 protein, Arabidopsis) RN - EC 2.3.2.27 (Ubiquitin-Protein Ligases) SB - IM MH - Arabidopsis/genetics/*metabolism/radiation effects MH - Arabidopsis Proteins/*chemistry/genetics/metabolism MH - Chromosomal Proteins, Non-Histone/*chemistry/genetics/metabolism MH - Genes, Plant MH - Mutation MH - Photoreceptors, Plant/*chemistry/genetics/metabolism MH - Protein Multimerization/radiation effects MH - Protein Structure, Quaternary/radiation effects MH - Repressor Proteins/genetics/metabolism MH - Signal Transduction/radiation effects MH - Ubiquitin-Protein Ligases/genetics/metabolism MH - Ultraviolet Rays PMC - PMC3549095 COIS- The authors declare no conflict of interest. EDAT- 2013/01/02 06:00 MHDA- 2013/03/15 06:00 PMCR- 2013/07/15 CRDT- 2013/01/02 06:00 PHST- 2013/01/02 06:00 [entrez] PHST- 2013/01/02 06:00 [pubmed] PHST- 2013/03/15 06:00 [medline] PHST- 2013/07/15 00:00 [pmc-release] AID - 1214237110 [pii] AID - 201214237 [pii] AID - 10.1073/pnas.1214237110 [doi] PST - ppublish SO - Proc Natl Acad Sci U S A. 2013 Jan 15;110(3):1113-8. doi: 10.1073/pnas.1214237110. Epub 2012 Dec 31.