TLP18.3, a novel thylakoid lumen protein regulating photosystem II repair cycle
TLP18.3, a novel thylakoid lumen protein regulating photosystem II repair cycle
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DOI：
10.1042/bj20070460
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发表时间：
2007-09-15
影响因子：
4.1
通讯作者：
Aro, Eva-Mari
中科院分区：
文献类型：
--
作者：
Sirpio, Sari;Allahverdiyeva, Yagut;Aro, Eva-Mari
对拟南芥类囊体相关多核糖体新生链复合物进行了蛋白质组学分析，以寻找参与类囊体蛋白复合物的生物发生、维持和周转的新蛋白，特别是表现出高周转率的PSII（光系统II）复合物。鉴定了四种未知蛋白，其中选择TLP18.3（（t）在bar hylakoid下（l）在bar umen下（p）在18.3kDa的bar rotein下）用于进一步分析。缺失TLP18.3蛋白的拟南芥突变体（SALK_109618和GABI-Kat 459 D12）表现出更高的PSII对光抑制的敏感性。Delta TLP18.3植物对强光的敏感性增加可能源于PSII单体在基粒堆叠中重新组装成二聚体的效率低下，以及基质暴露的类囊体中D1蛋白的周转受损。TLP18.3蛋白的这种双重功能与其均匀分布在基粒和基质类囊体之间是一致的。值得注意的是，缺乏TLP18.3蛋白不会导致PSII复合物的严重崩溃，这表明蛋白质的冗余有助于这些特定的修复步骤，以确保功能性PSII。Delta TLP18.3植物在标准生长条件下没有显示出清晰的视觉表型，但当在生长期间受到波动光的挑战时，Delta TLP18.3植物的生长迟缓是明显的。
A proteome analysis of Arabidopsis thaliana thylakoid-associated polysome nascent chain complexes was performed to find novel proteins involved in the biogenesis, maintenance and turnover of thylakoid protein complexes, in particular the PSII (photosystem II) complex, which exhibits a high turnover rate. Four unknown proteins were identified, of which TLP18.3 ((t) under bar hylakoid (l) under bar umen (p) under bar rotein of 18.3 kDa) was selected for further analysis. The Arabidopsis mutants (SALK_109618 and GABI-Kat 459D12) lacking the TLP18.3 protein showed higher susceptibility of PSII to photoinhibition. The increased susceptibility of Delta TLP18.3 plants to high light probably originates from an inefficient reassembly of PSII monomers into dimers in the grana stacks, as well as from an impaired turnover of the D1 protein in stroma exposed thylakoids. Such dual function of the TLP18.3 protein is in accordance with its even distribution between the grana and stroma thylakoids. Notably, the lack of the TLP18.3 protein does not lead to a severe collapse of the PSII complexes, suggesting a redundancy of proteins assisting these particular repair steps to assure functional PSII. The Delta TLP18.3 plants showed no clear visual phenotype under standard growth conditions, but when challenged by fluctuating light during growth, the retarded growth of Delta TLP18.3 plants was evident.