Photoregulatory Signal Transduction

描述（由申请人提供）：隐花色素蓝光光感受器首先在植物拟南芥中描述。这些光感受器在整个植物界广泛分布，如果不是无处不在的话，显然存在于所有高等植物以及蕨类植物和藻类中。隐花色素介导的蓝光信号影响多种植物过程，包括茎伸长、色素产生、基因表达、开花时间和昼夜节律的诱导。隐花色素也被描述用于动物，包括人类，其中它们在昼夜行为节律中发挥重要作用。 黑暗生长的转基因拟南芥植物表达隐花色素的C-末端结构域表现出的功能，通常与光生长的植物，表明隐花色素的信号传导特性驻留在这个C-末端结构域。显然，在黑暗中，天然隐花色素分子中的这种信号潜力受到抑制，这种抑制被光的作用所覆盖。在这里，我们建议定义的因素，是必要的重建在体外的光依赖性信号活性的隐花色素。此外，我们将定义的机制和域的隐花色素蛋白抑制隐花色素信号活性在黑暗中。我们将使用微阵列来识别其表达依赖于隐花色素的基因，我们将进行染色质免疫沉淀研究，以表征隐花色素和其他信号伙伴与染色质的关联。最后，我们将进一步表征拟南芥的新突变体，如隐花色素突变体，选择性缺乏蓝光信号，因此定义新的基因，调节光信号过程。

DESCRIPTION (provided by applicant): The cryptochrome blue light photoreceptors were first described in the plant Arabidopsis. These photoreceptors are widespread, if not ubiquitous, throughout the plant kingdom, apparently present in all higher plants as well as ferns and algae. Cryptochrome-mediated blue light signaling affects a variety of plant processes including stem elongation, pigment production, gene expression, flowering time, and the entrainment of circadian rhythms. Cryptochromes have also been described for animals, including humans, where they play an essential role in circadian behavioral rhythms. Dark-grown transgenic Arabidopsis plants expressing the C-terminal domain of cryptochrome exhibit features that are normally associated with light-grown plants, indicating that the signaling properties of cryptochrome reside within this C-terminal domain. Apparently this signaling potential is repressed in the native cryptochrome molecule in the dark, this repression being overridden by the action of light. Here we propose to define the factors that are necessary to reconstruct in vitro the light-dependent signaling activity of cryptochrome. In addition, we will define the mechanism and the domain of the cryptochrome protein necessary for repressing cryptochrome signaling activity in the dark. We will use microarrays to identify genes whose expression is dependent on cryptochrome and we will perform chromatin immunoprecipitation studies to characterize the association of cryptochrome and other signaling partners with chromatin. Finally, we will further characterize new mutants of Arabidopsis that, like cryptochrome mutants, are selectively deficient in blue light signaling and therefore define new genes that regulate the light signaling process.