Regulation of expression of genes coding for subunits of plant mitochondrial F1-ATPase

植物线粒体 F1-ATP 酶亚基编码基因表达的调控

• 批准号: 06660098
• 负责人: NAKAMURA Kenzo
• 金额: $ 1.28万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06660098/
• 关键词: Mitochondria; F1-ATPase; Transgenic Plants; Plant Genes; Regulation of Gene Expression; F1-ATPase; F_1ATPase

Mitochondrial F1-ATPase from dicotyledonous plants constitutes of 6 subunits and they are encoded by nuclear genes except for the alpha subunit which is encoded by the mitochondrial gene. We have previously identified correspondence of each of the four minor subunits of gamma, delta, delta'and epsilon from sweet potato mitochondria to subunits of F1-ATPase from other organisms by purification and cDNA cloning. In this research project, we could isolate nuclear genes for minor subunits of sweet potato mitochondrial F1-ATPase for the first time from the plant origin. For each of the subunts, multiple nuclear genes were identified and isolated, which shared high degree of sequence homology in the exon parts. The 5'-upstream regions of two genes for the delta subunit, DAM1 and DAM2, contained two insersion sequences that are absent in the other gene. Both of the GUS fusion genes with the 5'-upstream regions of these two genes were expressed in transformed tobacco cells and in transgenic tobacco plants, the results suggesting that both genes are actively transcribed genes. However, the level of GUS expression and the pattern of gene expression were different between the two GUS fusion genes. Although deletion of the Ins-1 insersion sequence in the DAM1 gene significantly enhanced the level of expression in transformed cells, it did not show any obvious effects on the expression in transgenic tobacco plants. The high-level expression of the DAM2-GUS fusion gene in roots of transgenic plants seemed to be due to the presence of Ins-2 sequence or other unique sequence in the far upstream region of the DAM2 gene.

双子叶植物线粒体F1-ATPase由6个亚基组成，除α亚基由线粒体基因编码外，其余均由核基因编码。我们先前已经通过纯化和克隆鉴定了甘薯线粒体的四个次要亚基--γ、β、β‘和epsilon与其他生物的F1-ATPase亚基的对应关系。在本研究项目中，我们首次从植物来源分离甘薯线粒体F1-ATPase亚基的核基因。对于每个亚基，都鉴定和分离了多个核基因，它们在外显子部分具有高度的序列同源性。DAM1和DAM2两个基因的5‘-上游区含有两个插入序列，这是另一个基因所没有的。GUS融合基因和这两个基因的5‘-上游区域都在转化烟草细胞和转基因烟草植株中表达，这表明这两个基因都是转录活跃的基因。然而，两个GUS融合基因的GUS表达水平和基因表达模式不同。虽然DAM1基因中INS-1插入序列的缺失显著提高了转化细胞中的表达水平，但对转基因烟草中的表达没有明显的影响。DAM2-GUS融合基因在转基因植物根中的高水平表达可能是由于在DAM2基因的远上游区域存在INS-2序列或其他独特的序列所致。