Arabidopsis Ferritin 1 (AtFer1) Gene Regulation by the Phosphate Starvation Response 1 (AtPHR1) Transcription Factor Reveals a Direct Molecular Link between Iron and Phosphate Homeostasis
Arabidopsis Ferritin 1 (AtFer1) Gene Regulation by the Phosphate Starvation Response 1 (AtPHR1) Transcription Factor Reveals a Direct Molecular Link between Iron and Phosphate Homeostasis
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DOI：
10.1074/jbc.m113.482281
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发表时间：
2013-08-02
影响因子：
4.8
通讯作者：
Gaymard, Frederic
中科院分区：
文献类型：
--
作者：
Bournier, Marc;Tissot, Nicolas;Gaymard, Frederic
酵母单杂交筛选允许选择Phr1作为与AtFer1铁蛋白基因启动子相互作用的因子。在迁移率改变分析中，Phr1及其同源物PHL1(Phr1-like 1)与AtFer1启动子的元件2相互作用，包含一个P1BS(Phr1结合位点)。在编码Phr1和PHL1基因的功能缺失突变体(Phr1phl1突变体)中，AtFer1对磷饥饿的响应完全丧失，表明这两个转录因子调控磷饥饿时AtFer1的表达。这种调控不涉及AtFer1启动子中存在的铁依赖调控序列(IDR)，而参与铁依赖调控。AtFer1的磷饥饿反应与植物的铁状态无关，而是由磷缺乏特异性地启动的。Perls DAB染色显示，Phr1phl1突变体中铁的组织化学定位发生了强烈的变化，表明Phr1和PHL1都是参与铁稳态调节的主要因素。
A yeast one-hybrid screening allowed the selection of PHR1 as a factor that interacted with the AtFer1 ferritin gene promoter. In mobility shift assays, PHR1 and its close homologue PHL1 (PHR1-like 1) interact with Element 2 of the AtFer1 promoter, containing a P1BS (PHR1 binding site). In a loss of function mutant for genes encoding PHR1 and PHL1 (phr1 phl1 mutant), the response of AtFer1 to phosphate starvation was completely lost, showing that the two transcription factors regulate AtFer1 expression upon phosphate starvation. This regulation does not involve the IDRS (iron-dependent regulatory sequence) present in the AtFer1 promoter and involved in the iron-dependent regulation. The phosphate starvation response of AtFer1 is not linked to the iron status of plants and is specifically initiated by phosphate deficiency. Histochemical localization of iron, visualized by Perls DAB staining, was strongly altered in a phr1 phl1 mutant, revealing that both PHR1 and PHL1 are major factors involved in the regulation of iron homeostasis.