The histidine kinase-related domain participates in phytochrome B function but is dispensable
The histidine kinase-related domain participates in phytochrome B function but is dispensable
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DOI：
10.1073/pnas.140520097
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发表时间：
2000-07-05
影响因子：
11.1
通讯作者：
Reed, JW
中科院分区：
文献类型：
--
作者：
Krall, L;Reed, JW
光敏色素是控制许多植物光反应的光感受器。光敏色素具有两个羧基末端结构域，称为PAS重复结构域和组氨酸激酶相关结构域。这些结构域各自与细菌组氨酸激酶结构域相关，并且生物化学研究表明光敏色素是光调节激酶。PAS重复结构域对于适当的光敏色素功能是重要的，并且可以与推定的信号传导伙伴相互作用。我们已经在拟南芥中发现了几个新的光敏色素B突变体，它们表达phyB蛋白，其中三个影响组氨酸激酶相关结构域。组氨酸激酶相关结构域中的点突变导致与无效突变体相似的表型，表明该结构域对phyB信号传导很重要。然而，去除大部分组氨酸激酶相关结构域的截短导致具有部分活性的phyB分子，表明该结构域是不稳定的。这些结果表明，光敏色素进化模块的方式。我们讨论了光敏色素信号中组氨酸激酶相关结构域的可能功能。
Phytochromes are photoreceptors that control many plant light responses. Phytochromes have two carboxyl-terminal structural domains called the PAS repeat domain and the histidine kinase-related domain. These domains are each related to bacterial histidine kinase domains, and biochemical studies suggest that phytochromes are light-regulated kinases, The PAS repeat domain is important for proper phytochrome function and can interact with putative signaling partners. We have characterized several new phytochrome B mutants in Arabidopsis that express phyB protein, three of which affect the histidine kinase-related domain. Point mutations in the histidine kinase-related domain cause phenotypes similar to those of null mutants, indicating that this domain is important for phyB signaling, However, a truncation that removes most of the histidine kinase-related domain results in a phyB molecule with partial activity, suggesting that this domain is dispensable. These results suggest that phytochromes evolved in modular fashion. We discuss possible functions of the histidine kinase-related domain in phytochrome signaling.