A mutually assured destruction mechanism attenuates light signaling in Arabidopsis

作者：Ni, Weimin; Xu, Shou-Ling; Tepperman, James M.; Stanley, David J.; Maltby, Dave A.; Gross, John D.; Burlingame, Alma L.; Wang, Zhi-Yong; Quail, Peter H.^*

来源：Science, 2014, 344(6188): 1160-1164.

DOI：10.1126/science.1250778

• BHLH TRANSCRIPTION FACTORS
• PHYTOCHROME B
• INDUCED PHOSPHORYLATION
• UBIQUITIN LIGASES
• DEGRADATION
• PIF3
• PROTEINS
• ACTS
• LOOP

After light-induced nuclear translocation, phytochrome photoreceptors interact with and induce rapid phosphorylation and degradation of basic helix-loop-helix transcription factors, such as PHYTOCHROME-INTERACTING FACTOR 3 (PIF3), to regulate gene expression. Concomitantly, this interaction triggers feedback reduction of phytochrome B (phyB) levels. Light-induced phosphorylation of PIF3 is necessary for the degradation of both proteins. We report that this PIF3 phosphorylation induces, and is necessary for, recruitment of LRB [Light-Response Bric-a-Brack/Tramtrack/Broad (BTB)] E3 ubiquitin ligases to the PIF3-phyB complex. The recruited LRBs promote concurrent polyubiqutination and degradation of both PIF3 and phyB in vivo. These data reveal a linked signal-transmission and attenuation mechanism involving mutually assured destruction of the receptor and its immediate signaling partner.

• 出版日期2014-6-6