Two interacting bZIP proteins are direct targets of COP1-mediated control of light-dependent gene expression in Arabidopsis
Two interacting bZIP proteins are direct targets of COP1-mediated control of light-dependent gene expression in Arabidopsis
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DOI：
10.1101/gad.969702
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发表时间：
2002-05-15
影响因子：
10.5
通讯作者：
Deng, XW
中科院分区：
文献类型：
--
作者：
Holm, M;Ma, LG;Deng, XW
拟南芥COP1在缺乏光的情况下抑制光形态建成。研究表明，在黑暗中，CON直接与bZIP转录因子HY5（光形态发生的正调节因子）相互作用，并促进其蛋白酶体介导的降解。在这里，我们确定了一种新的bZIP蛋白HYH，作为COP1的新靶点。我们确定了HYH和COP 1之间的物理和遗传相互作用，并表明这种相互作用的结果在黑暗中特异性降解的HYH。遗传分析表明，HYH主要参与蓝光调控发育和基因表达，并且HYH的功能与HY5的功能部分重叠。HYH蛋白而不是mRNA的积累依赖于HY5的存在。我们的数据表明，HYH和HYS可以，分别作为异二聚体和同源二聚体，从而介导光调控的重叠以及不同的靶基因的表达。我们认为COP1通过靶向降解细胞核中的多种光形态发生促进转录因子来介导光调控基因表达。
Arabidopsis COP1 acts to repress photomorphogenesis in the absence of light. it was shown that in the dark, CON directly interacts with the bZIP transcription factor HY5, a positive regulator of photomorphogenesis, and promotes its proteasome-mediated degradation. Here we identify a novel bZIP protein HYH, as a new target of COP1. We identify a physical and genetic interaction between HYH and COP1 and show that this interaction results in dark-specific degradation of HYH. Genetic analysis indicates that HYH is predominantly involved in blue-light regulation of development and gene expression, and that the function of HYH in part overlaps with that of HY5. The accumulation of HYH protein, not the mRNA, is dependent on the presence of HY5. Our data suggest that HYH and HYS can, respectively, act as heterodimers and homodimers, thus mediating light-regulated expression of overlapping as well as distinct target genes. We propose that COP1 mediates light control of gene expression through targeted degradation of multiple photomorphogenesis-promoting transcription factors in the nucleus.