质子梯度规则5确定了C. reinhardtiitii中的粉和脂质之间的储备分区
Maureen Saint-Sorny1, Alexandra Dimitriades2, Florian Delrue2
1CEA, CNRS, Aix-Marseille Université, UMR 7265, BIAM, Photosynthesis and Environment Team, CEA Cadarache, Saint-Paul-lez-Durance, France.
Physiologia plantarum
|September 27, 2024
概括
缺乏的克拉米多马纳斯突变体缺乏质子梯度调节5 (pgr5) 显示粉积累受损,三糖醇 (TAG) 生产增加. 这突出了循环电子流在营养应激期间碳分离中的作用.
科学领域:
- 光合作用和碳新陈代谢
- 藻类生理学 藻类生理学
- 分子生物学分子生物学
背景情况:
- 营养缺乏,特别是 (N) 缺乏,会在单细胞藻中引发储备积累 (粉,三糖醇 - TAG).
- 光合作用装置的重组和改变的碳分区是对N的关键反应.
- 循环电子流 (CEF) 对于在质体中维持细胞能量平衡 (ATP/NADPH比) 是至关重要的.
研究的目的:
- 为了研究光合作用调节和碳分离在N压力下的整合在Chllamydomonas reinhardtii.
- 为了阐明质子梯度调节5 (pgr5) 突变的作用,在CEF中受损,在粉和TAG积累中.
- 了解如何改变ATP/NADPH比率会在营养缺乏期间影响储备代谢.
主要方法:
- 在缺乏的条件下 (混合和光) 对野生类型和pgr5突变菌株的克拉米多马纳斯reinhardtii进行比较分析.
- 时间过程中测量粉和三糖醇 (TAG) 含量.
- 评估光合作用装置组件 (光系统II,叶绿素,cyt b6f复合体) 和与替代电子通路相关的蛋白质表达.
主要成果:
- 在最初三天的N压力期间,pgr5突变体现了粉降解而不是积累.
- 相反,pgr5突变显示出明显更高的TAG积累,独立于自的增加.
- 虽然所有菌株都提高了替代电子通路蛋白质的调节,并降解了光系统II/叶绿素,但pgr5优先保留了cyt b6f复合体.
结论:
- 在pgr5突变体中CEF受损导致在N压力下低的塑性ATP/NADPH比率.
- 这些较低的ATP/NADPH比率促进了粉的调动,并从缺乏开始增强了TAG的积累.
- 在Chlamydomonas的营养压力期间,CEF在调节粉和TAG之间的碳分区方面发挥着关键作用.
相关概念视频
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 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
ATP Driven Pumps I: An Overview
8.0K
ATP-driven pumps, also known as transport ATPases, are integral membrane proteins. They have binding sites for ATP located on the membrane's cytosolic side and the ion-conducting domain in the transmembrane region. These pumps use the free energy released from ATP hydrolysis to move the solutes across cell membranes against an electrochemical gradient.
There are four main types of ATP-driven pumps - P-type, V-type, F-type, and ABC transporter. All these pumps are of varying complexities and...
There are four main types of ATP-driven pumps - P-type, V-type, F-type, and ABC transporter. All these pumps are of varying complexities and...
8.0K
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 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
Chemiosmosis
97.3K
Oxidative phosphorylation is a highly efficient process that generates large amounts of adenosine triphosphate (ATP), the basic unit of energy that drives many cellular processes. Oxidative phosphorylation involves two processes— the electron transport chain and chemiosmosis.
Electron Transport Chain
The electron transport chain involves a series of protein complexes on the inner mitochondrial membrane that undergo a series of redox reactions. At the end of this chain, the electrons...
Electron Transport Chain
The electron transport chain involves a series of protein complexes on the inner mitochondrial membrane that undergo a series of redox reactions. At the end of this chain, the electrons...
97.3K


