Missense mutations define a restricted segment in the C-terminal domain of phytochrome A critical to its regulatory activity.
Missense mutations define a restricted segment in the C-terminal domain of phytochrome A critical to its regulatory activity.
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DOI：
10.1105/tpc.7.9.1433
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发表时间：
1995-09
期刊：
影响因子：
--
通讯作者：
Yong Xu;B. Parks;T. W. Short;P. Quail
中科院分区：
文献类型：
--
作者：
Yong Xu;B. Parks;T. W. Short;P. Quail
光敏色素家族的光感受器具有双重分子功能：感光，涉及光信号感知，和调节，涉及信号传递到下游转导组件。为了确定特定的光敏色素A（phyA）的调节活性所需的残基，我们进行了遗传筛选，以确定拟南芥突变体产生野生型水平的生物缺陷，但光化学活性和二聚体phyA分子。在鉴定的八个这样的突变体中，六个含有错义突变（包括在相同残基甘氨酸727中的三个），所述错义突变聚集在多肽的C-末端结构域中的限制性片段内。定量光生物学分析显示，不同等位基因之间保留不同程度的部分活性--这一结果与突变位置的保守程度一致。加上额外的数据，这些结果表明，这里确定的光感受器子域是至关重要的phyA和phyB的调节活性。
The phytochrome family of photoreceptors has dual molecular functions: photosensory, involving light signal perception, and regulatory, involving signal transfer to downstream transduction components. To define residues necessary specifically for the regulatory activity of phytochrome A (phyA), we undertook a genetic screen to identify Arabidopsis mutants producing wild-type levels of biologically defective but photochemically active and dimeric phyA molecules. Of eight such mutants identified, six contain missense mutations (including three in the same residue, glycine 727) clustered within a restricted segment in the C-terminal domain of the polypeptide. Quantitative photobiological analysis revealed retention of varying degrees of partial activity among the different alleles--a result consistent with the extent of conservation at the position mutated. Together with additional data, these results indicate that the photoreceptor subdomain identified here is critical to the regulatory activity of both phyA and phyB.