A Myb-related transcription factor is involved in the phytochrome regulation of an Arabidopsis Lhcb gene
A Myb-related transcription factor is involved in the phytochrome regulation of an Arabidopsis Lhcb gene
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DOI：
10.1105/tpc.9.4.491
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发表时间：
1997-04-01
期刊：
影响因子：
11.6
通讯作者：
Tobin, EM
中科院分区：
文献类型：
--
作者：
Wang, ZY;Kenigsbuch, D;Tobin, EM
我们已经分离出一种名为CCA1的蛋白质基因。该蛋白可以结合到拟南芥光收获叶绿素a/b蛋白基因Lhcb1*3的启动子区域，这是光敏色素调控所必需的。CCA1蛋白与Lhcb1*3启动子AA(A)/(C)AATCT中的两个不完全重复相互作用，该序列在Lhcb基因中是保守的。CCA1的N端附近有一个区域，与Myb蛋白DNA结合域的重复序列有一定的同源性，这是与Lhcb1*3启动子结合所必需的。在表达CCA1反义RNA的转基因拟南芥中，光敏色素诱导内源性Lhcbl*3基因的表达减少，而编码核酮糖-1,5-二磷酸羧化酶/加氧酶小亚基的另一种光敏色素调控基因rbcS-1A的表达不受影响。因此，CCA1蛋白在短暂的红色光照下作为Lhcb1*3转录的特异性激活因子。当黄化的幼苗转移到光照下时，CCA1 RNA的表达会短暂增加。我们得出结论，CCA1蛋白是光敏色素信号转导途径功能的关键因素，导致拟南芥Lhcb基因转录增加。
We have isolated the gene for a protein designated CCA1. This protein can bind to a region of the promoter of an Arabidopsis light-harvesting chlorophyll a/b protein gene, Lhcb1*3, which is necessary for its regulation by phytochrome. The CCA1 protein interacted with two imperfect repeats in the Lhcb1*3 promoter, AA(A)/(C)AATCT, a sequence that is conserved in Lhcb genes. A region near the N terminus of CCA1, which has some homology to the repeated sequence found in the DNA binding domain of Myb proteins, is required for binding to the Lhcb1*3 promoter. Lines of transgenic Arabidopsis plants expressing antisense RNA for CCA1 showed reduced phytochrome induction of the endogenous Lhcbl*3 gene, whereas expression of another phytochrome-regulated gene, rbcS-1A, which encodes the small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase, was not affected. Thus, the CCA1 protein acts as a specific activator of Lhcb1*3 transcription in response to brief red illumination, The expression of CCA1 RNA was itself transiently increased when etiolated seedlings were transferred to light. We conclude that the CCA1 protein is a key element in the functioning of the phytochrome signal transduction pathway leading to increased transcription of this Lhcb gene in Arabidopsis.