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Joint study on the search for phytochrome-binding protein

寻找光敏色素结合蛋白的联合研究

基本信息

批准号：
07044206
负责人：
WADA Masamitsu
金额：
$ 9.54万
依托单位：
TOKYO METROPOLITAN UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07044206/
关键词：
Phytochrome protein kinase fern Lhcb moss protonema branching シダコケ藻類裸子植物

项目摘要

We have cloned 4 phytochrome genes and 3 cDNAs of them from fern Adiantum capillus-veneris. One of the sequences has a quite unique structure, i.e.N-terminus half of the gene has a conventional phytochrome structure, but C-terminus half has a structure of typical protein kinase. We also cloned and sequenced 5 genes and their cDNAs of blue light receptors. One of them has a predicted trans-membrane segment, indicating the protein encoded by this gene might localize in the plasma membrane and mediate chloroplast photoorientaion of apical swelling of protonemata. The photoreceptive site of these phenomena were found to be localized in the plasma membrane. We think that almost all photoreceptors involving the photomorphogenesis in fern are now in our hands. We are now characterizing which photoreceptor mediates which photoresponses, and we hope that we will dissolve signal transduction pathways of these photoreceptors in the near future.Red light induced gene expression was revealed in the first time in spore germination. Gene expression of light harvesting chlorophyll binding protein (Lhcb) was controlled by phytochrome, and red/farred photoreversibility was shown.Side branch formation in protonemata of the moss Ceratodon purpureus was found to be mediated by phytochrome. The frequency of red-light-induced branch formation differed between cells of differeny ages. The position of branching within the cell depended on the high absorption of red light. An aphototropic mutant ptr 116 which is deficient of biosynthesis of phytochrome chromophore, showed no branch formation by red light but was rescued by supplement of biliverdin, a precursor of phytochrome chromophore, in the culture medium.

我们从铁线蕨中克隆了4个光敏色素基因和3个cDNA。其中一个序列具有非常独特的结构，即基因的N-末端一半具有常规的光敏色素结构，而C-末端一半具有典型的蛋白激酶结构。我们还克隆了5个蓝光受体基因及其cDNA序列。其中一个基因具有一个预测的跨膜片段，表明该基因编码的蛋白质可能定位于质膜，并介导叶绿体光定向的原丝体顶端肿胀。发现这些现象的光感受位点位于质膜上。我们认为，几乎所有涉及蕨类植物光形态建成的光感受器现在都掌握在我们手中。我们目前正在研究哪些光感受器介导哪些光反应，希望在不久的将来能够解开这些光感受器的信号转导途径。首次在孢子萌发过程中发现红光诱导的基因表达。光敏色素控制捕光叶绿素结合蛋白（Lhcb）基因的表达，并具有红光/远红光光可逆性，研究发现光敏色素介导了象鼻草（Ceratodon purpureus）原丝体侧分支的形成。不同年龄的细胞红光诱导分支形成的频率不同。细胞内分支的位置取决于对红光的高吸收。一株光敏色素发色团生物合成缺陷的隐光突变株ptr 116在红光下不形成分支，但在培养基中添加光敏色素发色团前体胆绿素后，该突变株被拯救。