Record Details

Light-induced phosphorylation and degradation of the negative regulator PIF1 depends upon its direct physical interactions with photoactivated phytochromes

NIPGR Digital Knowledge Repository (NDKR)

View Archive Info
 
 
Field Value
 
Title Light-induced phosphorylation and degradation of the negative regulator PIF1 depends upon its direct physical interactions with photoactivated phytochromes
 
Creator Shen, Hui
Zhu, Ling
Castillon, Alicia
Majee, Manoj
Downie, Bruce
Huq, Enamul
 
Subject phytochrome
photoreceptors
Arabidopsis
Photoactivated
Phosphorylation
Light-Induced
 
Description The phytochrome (phy) family of photoreceptors regulates changes in gene expression in response to red/far-red light
signals in part by physically interacting with constitutively nucleus-localized phy-interacting basic helix-loop-helix transcription factors (PIFs). Here, we show that PIF1, the member with the highest affinity for phys, is strongly sensitive to the
quality and quantity of light. phyA plays a dominant role in regulating the degradation of PIF1 following initial light exposure,
while phyB and phyD and possibly other phys also influence PIF1 degradation after prolonged illumination. PIF1 is rapidly
phosphorylated and ubiquitinated under red and far-red light before being degraded with a half-life of ~1 to 2 min under red
light. Although PIF1 interacts with phyB through a conserved active phyB binding motif, it interacts with phyA through a
novel active phyA binding motif. phy interaction is necessary but not sufficient for the light-induced phosphorylation and
degradation of PIF1. Domain-mapping studies reveal that the phy interaction, light-induced degradation, and transcriptional
activation domains are located at the N-terminal 150–amino acid region of PIF1. Unlike PIF3, PIF1 does not interact with the
two halves of either phyA or phyB separately. Moreover, overexpression of a light-stable truncated form of PIF1 causes
constitutively photomorphogenic phenotypes in the dark. Taken together, these data suggest that removal of the negative
regulators (e.g., PIFs) by light-induced proteolytic degradation might be sufficient to promote photomorphogenesis.
This work was supported by National Science
Foundation Grant MCB-0449646 to B.D. and by National Science
Foundation Grant IBN-0418653 and a set-up fund from the University
of Texas at Austin to E.H.
 
Date 2013-11-12T06:22:07Z
2013-11-12T06:22:07Z
2008
21 May 2008
 
Type Article
 
Identifier Plant Cell, 20(6): 1586-1602
http://hdl.handle.net/123456789/101
 
Language en
 
Publisher American Society of Plant Biologists