共 54 条
Phosphorylation by CK2 Enhances the Rapid Light-induced Degradation of Phytochrome Interacting Factor 1 in Arabidopsis
被引:85
作者:
Bu, Qingyun
Zhu, Ling
Dennis, Michael D.
[2
]
Yu, Lu
Lu, Sheen X.
[4
]
Person, Maria D.
[3
]
Tobin, Elaine M.
[4
]
Browning, Karen S.
[2
,3
]
Huq, Enamul
[1
,3
]
机构:
[1] Univ Texas Austin, Sect Mol Cell & Dev Biol, Biol Labs 311 A6700, Austin, TX 78712 USA
[2] Univ Texas Austin, Dept Chem & Biochem, Austin, TX 78712 USA
[3] Univ Texas Austin, Inst Cellular & Mol Biol, Austin, TX 78712 USA
[4] Univ Calif Los Angeles, Dept Mol Cell & Dev Biol, Los Angeles, CA 90095 USA
基金:
美国国家科学基金会;
美国国家卫生研究院;
关键词:
PROTEIN-KINASE CK2;
TRANSLATION INITIATION-FACTORS;
REGULATED GENE-EXPRESSION;
TRANSCRIPTION FACTORS;
MEDIATED DEGRADATION;
OSCILLATOR FUNCTION;
SIGNALING NETWORKS;
RED-LIGHT;
PHOTOMORPHOGENESIS;
SEEDLINGS;
D O I:
10.1074/jbc.M110.186882
中图分类号:
Q5 [生物化学];
Q7 [分子生物学];
学科分类号:
071010 ;
081704 ;
摘要:
The phytochrome family of sensory photoreceptors interacts with phytochrome interacting factors (PIFs), repressors of photomorphogenesis, in response to environmental light signals and induces rapid phosphorylation and degradation of PIFs to promote photomorphogenesis. However, the kinase that phosphorylates PIFs is still unknown. Here we show that CK2 directly phosphorylates PIF1 at multiple sites. alpha 1 and alpha 2 subunits individually phosphorylated PIF1 weakly in vitro. However, each of four beta subunits strongly stimulated phosphorylation of PIF1 by alpha 1 or alpha 2. Mapping of the phosphorylation sites identified seven Ser/Thr residues scattered throughout PIF1. Ser/Thr to Ala scanning mutations at all seven sites eliminated CK2-mediated phosphorylation of PIF1 in vitro. Moreover, the rate of degradation of the Ser/Thr to Ala mutant PIF1 was significantly reduced compared with wild-type PIF1 in transgenic plants. In addition, hypocotyl lengths of the mutant PIF1 transgenic plants were much longer than the wild-type PIF1 transgenic plants under light, suggesting that the mutant PIF1 is suppressing photomorphogenesis. Taken together, these data suggest that CK2-mediated phosphorylation enhances the light-induced degradation of PIF1 to promote photomorphogenesis.
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页码:12066 / 12074
页数:9
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