Mechanisms of signal transduction which controls carbon-dioxide fixation

控制二氧化碳固定的信号转导机制

基本信息

批准号：
09660357
负责人：
FUKUZAWA Hideya
金额：
$ 2.11万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

项目摘要

Several chimeric constructs were generated by fusing series of 5'-upstream region of CAHl to the arylsulfatase reporter gene (ars) driven by βィイD22ィエD2-tublin minimal promoter. Some Chlamydomonas cells transformed with the chimeric constructs expressed the reporter gene in response to changes in the external COィイD22ィエD2 concentration. The 5'-upstream region is divided into two parts ; a part functions as a silencer in high-COィイD22ィエD2 condition and the other part functions as an enhancer in low-COィイD22ィエD2 condition.Seven high-COィイD22ィエD2-requiring mutants, which cannot grow as wild type Chlamydomonas does in air level of COィイD22ィエD2(0.04%), were isolated by gene tagging. It was indicated that these mutants carried lesions in genes related to the carbon concentrating mechanism (CCM) or the signal transduction pathway between sensing changes of environmental COィイD22ィエD2 concentration and induction of CCM-related genes. By using an indexed PAC genomic library, two mutants were complemented. The mutation of a mutant C1, which accumulate less inorganic carbon (Ci) into the cell, was complemented by a PAC clone containing 20-kb of genomic DNA. This suggests that Ci-transport related genes could be encoded within this DNA fragment. Another mutant C16, which does not induce CCM-related genes in low-COィイD22ィエD2, was transformed by a DNA fragment which correspond to the flanking sequences of the NIT1 insertional locus and the transformants recovered the induction of CCM-related genes. The cloned DNA fragment encoded a gene which does not show significant homology with any previously known genes.

通过βIYD22-Tublin最小启动子驱动的芳基硫酸酯酶报告基因（ARS），通过将CAHL的5'上游区域的融合序列与芳基硫酸糖报告基因（ARS）产生。一些用嵌合构建体转化的衣原体细胞，表达了记者基因，以响应外部Coiy D22-D2浓度的变化。 5'上游区域分为两个部分；一个零件在高污染的D22-D2条件下充当消音器，而另一部分则在低coi d22征值的突变体中起增强子的作用。七个高coi d22替代突变体不能随着野生型chlamydomonas的生长而在COI D22-D2-DECIPHER d2（0.04％）的空气中生长，这是野生型的chlamyonas的作用。据表明，这些突变体在与碳浓缩机制（CCM）相关的基因中携带的水平或环境COI D22E D2浓度的灵敏度变化与CCM相关基因诱导之间的信号转移途径。通过使用索引的PAC基因组库，完成了两个突变体。突变体C1的突变由含有20-kb基因组DNA的PAC克隆完成，该突变体C1的无机碳（CI）积累了较少的无机碳（CI）。这表明可以在此DNA片段中编码CI-Transport相关的基因。另一个不影响低COII D22中CCM相关基因的突变体C16是由DNA片段转化的，DNA片段对应于NIT1插入基因座的侧翼序列，转化体恢复了CCM相关基因的诱导。克隆的DNA片段编码了一个基因，该基因与任何先前已知的基因都没有明显的同源性。