Photoexcited CRY2 Interacts with CIB1 to Regulate Transcription and Floral Initiation in Arabidopsis
Photoexcited CRY2 Interacts with CIB1 to Regulate Transcription and Floral Initiation in Arabidopsis
复制标题
DOI：
10.1126/science.1163927
复制
发表时间：
2008-12-05
期刊：
影响因子：
56.9
通讯作者：
Lin, Chentao
中科院分区：
文献类型：
--
作者：
Liu, Hongtao;Yu, Xuhong;Lin, Chentao
隐花色素（CRY）是一类光裂合酶样蓝光受体，在植物和动物体内介导光反应.植物隐花色素如何对蓝光做出反应还不清楚。本文报道了拟南芥CIB 1（隐花色素相互作用碱性-螺旋-环-螺旋）蛋白的鉴定和表征. CIB 1在酵母和拟南芥细胞中以蓝光特异性的方式与CIB 2（隐花色素2）相互作用，并且它与另外的CIB 1相关蛋白一起作用以促进CIB 2依赖的花起始。CIB 1在体外与G盒（CACGTG）结合的亲和力高于其与其他E盒元件（CANNTG）的相互作用。然而，CIB 1刺激FT信使RNA表达，并且它与FT基因的染色质DNA相互作用，所述FT基因具有除G盒之外的各种E盒元件。我们认为隐花色素与CIB 1和CIB 1相关蛋白的蓝光依赖性相互作用代表了植物早期光感受器信号传导机制。
Cryptochromes (CRY) are photolyase- like blue- light receptors that mediate light responses in plants and animals. How plant cryptochromes act in response to blue light is not well understood. We report here the identification and characterization of the Arabidopsis CIB1 ( cryptochrome- interacting basic- helix- loop- helix) protein. CIB1 interacts with CRY2 ( cryptochrome 2) in a blue light- specific manner in yeast and Arabidopsis cells, and it acts together with additional CIB1- related proteins to promote CRY2- dependent floral initiation. CIB1 binds to G box ( CACGTG) in vitro with a higher affinity than its interaction with other E- box elements ( CANNTG). However, CIB1 stimulates FT messenger RNA expression, and it interacts with chromatin DNA of the FT gene that possesses various E- box elements except G box. We propose that the blue light- dependent interaction of cryptochrome( s) with CIB1 and CIB1- related proteins represents an early photoreceptor signaling mechanism in plants.