ACTIVITY OF THE CHLAMYDOMONAS CHLOROPLAST RBCL GENE PROMOTER IS ENHANCED BY A REMOTE SEQUENCE ELEMENT
ACTIVITY OF THE CHLAMYDOMONAS CHLOROPLAST RBCL GENE PROMOTER IS ENHANCED BY A REMOTE SEQUENCE ELEMENT
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DOI：
10.1073/pnas.91.23.10819
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发表时间：
1994-11-08
影响因子：
11.1
通讯作者：
BOGORAD, L
中科院分区：
文献类型：
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作者：
KLEIN, U;SALVADOR, ML;BOGORAD, L
叶绿体基因rbcL编码核酮糖二磷酸羧化酶大亚基。在莱茵衣藻中，该基因比迄今为止研究的任何其他编码叶绿体基因的蛋白质更活跃地转录。为了描述rbcL基因启动子，嵌合报告基因含有rbcL基因的5'区域的片段融合到细菌uidA基因的编码序列，编码β-葡萄糖醛酸酶，被稳定地引入叶绿体基因组的衣原体的微粒轰击。在体内转基因细胞系中测定内源基因和导入基因的相对转录速率。基本rbcL启动子位于从位置-18至+63延伸的基因区域内，以位置+1作为转录起始位点。仅含有基本启动子的嵌合报告基因的转录活性仅为内源rbcL基因的1-15%，这取决于细胞生长和测试的条件。然而，含有延伸至+170或更远位置的rbcL序列的嵌合基因以与内源基因大约相同的速率转录。缺失位置+170和+126之间的序列，正好在蛋白质编码区内，将转录速率降低到仅用基本启动子的报告基因的转录速率。
The chloroplast gene rbcL encodes the large subunit of ribulose bisphosphate carboxylase. In Chlamydomonas reinhardtii, this gene is transcribed more actively than any other protein encoding chloroplast gene studied to date. To delineate the rbcL gene promoter, chimeric reporter genes containing fragments of the 5' region of the rbcL gene fused to the coding sequence of the bacterial uidA gene, encoding beta-glucuronidase, were stably introduced into the chloroplast genome of Chlamydomonas by microprojectile bombardment. The relative transcription rates of endogenous and introduced genes were determined in transgenic cell lines in vivo. The basic rbcL promoter is located within the region of the gene extending from positions -18 to +63, taking position +1 as the site of initiation of transcription. A chimeric reporter gene containing only the basic promoter is transcribed only 1-15% as actively as the endogenous rbcL gene, depending on the conditions under which cells are grown and tested. However, a chimeric gene containing rbcL sequences extending to position +170 or beyond is transcribed at about the same rate as the endogenous gene. Deletion of the sequence between positions +170 and +126, well within the protein-encoding region, reduces the rate of transcription to that of reporter genes with the basic promoter alone.