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Turn over regulation of photosystem II proteins by the light-dependent transcription in chloroplasts

通过叶绿体中的光依赖性转录来翻转光系统 II 蛋白的调节

基本信息

批准号：
08836004
负责人：
SHIINA Takashi
金额：
$ 1.22万
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：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08836004/
关键词：
chloroplast transcription mRNA transgenic plant light Ca^<2+>photosystem II D1蛋白質 D2蛋白質シグマ因子 psbD psbA σ因子 RNAポリメラーゼ

项目摘要

Photosynthesis related genes encoded by plastid genome are transcribed by a plastid-encoded plastid RNA polymerase (PEP). However, no transcription factor is encoded by plastid genome, It is likely that nuclear encoded transcription factors, for example plastid sigma factors, are involved in the regulation of plastid gene transcription. In this work, we analyzed fine structure of several PEP promoters by in vitro transcription and plastid transformation and revealed the role of nuclear-encoded transcription factors on plastid promoter recognition. We also studied the signal transduction involved in nuclear-encoded photosynthesis genes and the regulation of the electron transfer in photosystem II.RESULTSThe psbD promoter upstream of the psbD gene encoding photosystem II D2 protein is reversibly activated by light and regulated by endogenous circadian rhythm, too. There are two transcription enhancing elements upstream of -35 element, but the promoter core is likely to be involved in the light-dependent and circadian- regulated transcription.The rbcL core promoter is sufficient for the light-dependent transcription. Furthermore, we revealed that reduced rbcL transcription in the dark is compensated by increased mRNA stability.Mesophyll cell specific nuclear-encoded cab-ml expression is controlled by cytosolic Ca^<2+> level. Ca^<2+> signaling is mediated by a 54-bp sequence in the 5' flanking region.Photosystem II PsbL is involved in electron transfer at the donor side from Tyr-Z to P_<680>^+. Amino acid residues in the carboxyl-terminal region is essential for the PsbL function.

质体基因组编码的光合作用相关基因由质体编码的质体RNA聚合酶（PEP）转录。然而，质体基因组不编码任何转录因子，核编码的转录因子，例如质体σ因子，可能参与质体基因转录的调控。本研究通过体外转录和质体转化的方法分析了几种PEP启动子的精细结构，揭示了核转录因子在质体启动子识别中的作用。我们还研究了核编码光合作用基因的信号转导和光系统II电子传递的调控。研究结果表明，编码光系统II D2蛋白的psbD基因上游的psbD启动子可被光可逆激活，并受内源性昼夜节律的调控。-35元件上游有两个转录增强元件，但启动子核心可能参与光依赖性和昼夜节律调节的转录，rbcL核心启动子足以进行光依赖性转录。此外，我们还发现，在黑暗条件下rbcL转录的减少可以通过mRNA稳定性的增加来补偿，叶肉细胞特异性的核编码cab-ml的表达受细胞质Ca^<2+>水平的控制。Ca^2+信号由5'侧翼区的54 bp序列介导，光系统II PsbL参与供体侧Tyr-Z到P ^+的电子传递<680>。羧基末端区域的氨基酸残基对于PsbL功能是必需的。