Chimeric proteins between cry1 and cry2 Arabidopsis blue light photoreceptors indicate overlapping functions and varying protein stability
Chimeric proteins between cry1 and cry2 Arabidopsis blue light photoreceptors indicate overlapping functions and varying protein stability
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DOI：
10.1105/tpc.10.2.197
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发表时间：
1998-02-01
期刊：
影响因子：
11.6
通讯作者：
Cashmore, AR
中科院分区：
文献类型：
--
作者：
Ahmad, M;Jarillo, JA;Cashmore, AR
来自拟南芥的一种蓝光（隐色素）光感受器cry1最近被发现，并被证明介导许多蓝光依赖性表型。与光敏色素类似，隐花色素光感受器由一个同源基因家族编码，在n端发色团结合区域内具有相当大的氨基酸序列相似性。拟南芥隐色素基因家族的两个成员（CRY1和CRY2）在功能上重叠，但它们的蛋白质稳定性不同：CRY2在激活光感受器的光影响下（绿色、蓝色和紫外线）会迅速降解，但CRY1不会。在这里，我们通过在转基因植物中过表达cry1和cry2融合构建体，证明它们的结构域在功能上是可互换的。杂交受体蛋白介导类似cry1的功能，包括抑制下胚轴伸长和蓝光依赖性花青素积累；活性的差异似乎与不同的蛋白质稳定性有关。由于cry2在弱光条件下积累水平较高，因此在光照受限的野生型植物中可能具有更大的意义。
A blue light (cryptochrome) photoreceptor from Arabidopsis, cry1, has been identified recently and shown to mediate a number of blue light-dependent phenotypes. Similar to phytochrome, the cryptochrome photoreceptors are encoded by a gene family of homologous members with considerable amino acid sequence similarity within the N-terminal chromophore binding domain. The two members of the Arabidopsis cryptochrome gene family (CRY1 and CRY2) overlap in function, but their proteins differ in stability: cry2 is rapidly degraded under light fluences (green, blue, and UV) that activate the photoreceptor, but cry1 is not. Here, we demonstrate by overexpression in transgenic plants of cry1 and cry2 fusion constructs that their domains are functionally interchangeable. Hybrid receptor proteins mediate functions similar to cry1 and include inhibition of hypocotyl elongation and blue light-dependent anthocyanin accumulation; differences in activity appear to be correlated with differing protein stability. Because cry2 accumulates to high levels under low-light intensities, it may have greater significance in wild-type plants under conditions when light is limited.