克拉米多马纳斯psb28突变体的复杂分析显示,TEF5是早期的PSII组装因子
Julia Lang1, Katharina König1, Benedikt Venn2
1Molecular Biotechnology & Systems Biology, RPTU Kaiserslautern-Landau, D-67663 Kaiserslautern, Germany.
The Plant cell
|March 17, 2025
概括
缺少Psb28和TEF5辅助因子严重损害了Chlamydomonas的光系统II (PSII) 组合,这表明这种藻类的蛋白质质量控制系统强大.
科学领域:
- 植物生物学 植物生物学
- 光合作用研究研究 光合作用研究
- 分子生物学分子生物学
背景情况:
- 光系统II (PSII) 组装是一个复杂的过程,需要许多辅助因素.
- 众所周知,psb28参与PSII组装,但其精确的作用,特别是在藻类中,仍然不完全理解.
- 在PSII组合中,TEF5 (THYLAKOID ENRICHED FRACTION 5),Arabidopsis PHOTOSYSTEM B PROTEIN 33/LIGHT HARVESTING-LIKE 8的同类,在PSII组合中的功能基本上没有特征.
研究的目的:
- 为了研究Psb28在PSII组装中的作用,在藻类中进行研究 Chlamydomonas reinhardtii.
- 通过复合体分析,识别和描述涉及PSII生物发生的新型辅助因素.
- 阐明TEF5在PSII和PSI组装和甲状腺组织的背景下的功能.
主要方法:
- 对克拉米多马纳斯psb28和tef5无基因突变的生成和表型分析.
- 使用生物化学和生物物理技术分析PSII和PSI超复合体,二元体和单元体.
- 复杂的分析,以识别蛋白质-蛋白质相互作用和组装中间体.
- 叶绿体形态学和甲状腺组织分析.
主要成果:
- 这种psb28无突变体的PSII组合严重受损,早期中间体 (RCII,CP43mod,D1mod) 和减少的PSII复合体积聚.
- 复杂的配置文件确定了TEF5与RCII和PSI相互作用.
- tef5无变种也表现出严重的PSII组装缺陷,累积了RCII和CP43mod,并且缺乏RC47.
- 这两种突变都显示出改变了甲状腺组织和叶绿体形态,减少了CP47和PsbH的合成,表明了负面反.
结论:
- 与蓝菌不同的是,Psb28在Chlamydomonas的PSII组装中发挥着关键作用.
- TEF5是PSII组装必不可少的新型辅助因子,可能参与RCII光保护或成熟.
- 在这两种突变体中,早期组装中间体的积累表明了反调节机制.
- 与蓝藻和陆地植物相比,Chlamydomonas对光合作用复合体具有更复杂的蛋白质质量控制系统.
相关概念视频
Protein Transport to the Inner Chloroplast Membrane
2.1K
Proteins targeted to the inner chloroplast membrane, or plastid proteins, are transported by two general pathways: the stop-transfer and the re-insertion or post-import pathways. Most plastid proteins carry N-terminal transit sequences and internal import sequences targeting it to the specific chloroplast subcompartment. Proteins targeted by the stop-transfer pathway have internal hydrophobic sequences that inhibit their translocation into the stroma. As a result, these precursors are arrested...
2.1K
Protein Transport to the Stroma
1.8K
Chloroplasts are triple membrane structures with an outer membrane, an inner membrane, and a thylakoid membrane, each containing distinct metabolite transporters, membrane translocons, and enzymes. Appropriate sorting and translocating these proteins to their correct membrane systems is essential for chloroplast function.
Protein complexes called the translocon of the outer chloroplast membrane or TOC complex, and the translocon of the inner chloroplast membrane or TIC complex mediate the...
Protein complexes called the translocon of the outer chloroplast membrane or TOC complex, and the translocon of the inner chloroplast membrane or TIC complex mediate the...
1.8K
Protein Transport to the Outer Chloroplast Membrane
2.0K
Chloroplast outer membrane proteins encoded by the nucleus are synthesized in the cytosol. Soon after synthesis, they bind cytosolic factors such as 14-3-3 protein and the Hsp70 chaperones that keep these precursors in an unfolded state until their translocation.
Two models describe the mechanism of precursor recognition and entry across the outer membrane through the TOC complex. Model 1 suggests the newly synthesized precursor binds to the TOC receptor 159 and forms a complex.
Two models describe the mechanism of precursor recognition and entry across the outer membrane through the TOC complex. Model 1 suggests the newly synthesized precursor binds to the TOC receptor 159 and forms a complex.
2.0K
Protein Complex Assembly
10.6K
Proteins can form homomeric complexes with another unit of the same protein or heteromeric complexes with different types. Most protein complexes self-assemble spontaneously via ordered pathways, while some proteins need assembly factors that guide their proper assembly. Despite the crowded intracellular environment, proteins usually interact with their correct partners and form functional complexes.
Many viruses self-assemble into a fully functional unit using the infected host cell to...
Many viruses self-assemble into a fully functional unit using the infected host cell to...
10.6K
Photosystems
4.8K
Photosystems are multiprotein complexes that form the functional units of photosynthesis in plants, algae, and cyanobacteria. They are found embedded in the membrane of tiny sac-like structures called thylakoids placed inside the chloroplast.
Functioning of Photosystems
Photosystems contain many pigment molecules, such as chlorophylls and carotenoids, arranged in a particular organization across two domains — the antenna complex and the reaction center. The main aim of the pigment...
Functioning of Photosystems
Photosystems contain many pigment molecules, such as chlorophylls and carotenoids, arranged in a particular organization across two domains — the antenna complex and the reaction center. The main aim of the pigment...
4.8K
Protein Transport to the Thylakoids
2.2K
Thylakoids are membrane-bound sac-like structures within the chloroplast that serve as sites for photosynthesis. Thylakoid lumen contains many electron transport proteins and is enclosed by a thylakoid membrane rich in the light-harvesting complex. Proteins targeted to the thylakoids are transported as precursors and are sorted by the general TOC/TIC import pathway. Once the precursor reaches the stroma, stromal processing peptidases remove their transit signal and expose thylakoid signal...
2.2K


