Regulation of thylakoid protein phosphorylation: Characterization of novel enzymes, mechanisms and physiological relevance for acclimation to light changes

类囊体蛋白磷酸化的调节：新酶的表征、机制和适应光变化的生理相关性

• 批准号: 200248312
• 负责人: Professor Dr. Dario Leister
• 金额: --
• 依托单位: Lehrstuhl für Molekularbiologie der Pflanzen
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2011
• 资助国家: 德国
• 起止时间: 2010-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/200248312?language=en
• 关键词: Regulation; thylakoid; protein; phosphorylation; Characterization

Phosphorylation of the light-harvesting complex II (LHCII) and PSII core proteins requires the kinases STN7 and STN8, respectively. LHCII dephosphorylation depends on the phosphatase TAP38. The PSII core protein phosphatase and an additional PSII core protein kinase still await their identification. Other open fundamental questions concern the actual physiological relevance of LHCII and PSII core protein phosphorylation, and the mechanisms by which STN7 is regulated and by which STN7 mediates the gene expression changes associated with the long-term photosynthetic acclimation (LTR). Moreover, although STN8 is re-quired for modulation of thylakoid ultrastructure, we found that this process does not require PSII core protein phosphorylation. To identify the PSII core protein phosphatase and the additional PSII core protein kinase we will combine genomics and subcellular localisation experiments. To clarify the actual physiological role of thylakoid protein phosphorylation we will characterise in detail mutants and overexpressor lines for the known thylakoid protein kinases and phosphatases. Moreover, we will identify and characterize those substrates of STN8 that confer the ultrastructural changes. In preliminary experiments we found that STN7 abundance and LHCII phosphorylation correlate; therefore, we will analyse STN7 expression at the transcript and protein level. To identify the substrate of STN7 that mediates LTR signalling, as well as the LTR target genes, comparative chloroplast phosphoproteome and whole-genome transcriptome analyses will be em-ployed.

光捕获复合物 II (LHCII) 和 PSII 核心蛋白的磷酸化分别需要激酶 STN7 和 STN8。 LHCII 去磷酸化依赖于磷酸酶 TAP38。 PSII 核心蛋白磷酸酶和其他 PSII 核心蛋白激酶仍在等待鉴定。其他开放的基本问题涉及 LHCII 和 PSII 核心蛋白磷酸化的实际生理相关性、STN7 的调节机制以及 STN7 介导与长期光合适应 (LTR) 相关的基因表达变化的机制。此外，虽然类囊体超微结构的调节需要STN8，但我们发现该过程不需要PSII核心蛋白磷酸化。为了鉴定 PSII 核心蛋白磷酸酶和其他 PSII 核心蛋白激酶，我们将结合基因组学和亚细胞定位实验。为了阐明类囊体蛋白磷酸化的实际生理作用，我们将详细描述已知类囊体蛋白激酶和磷酸酶的突变体和过表达系。此外，我们将识别和表征那些赋予超微结构变化的 STN8 底物。在初步实验中，我们发现 STN7 丰度与 LHCII 磷酸化相关；因此，我们将在转录本和蛋白质水平上分析STN7的表达。为了鉴定介导 LTR 信号传导的 STN7 底物以及 LTR 靶基因，将采用比较叶绿体磷酸蛋白质组和全基因组转录组分析。