循环时钟蛋白 KaiB 的温度依赖的折叠切换机制
bioRxiv : the preprint server for biology
|June 3, 2024
概括
蓝藻细菌的昼夜钟蛋白 KaiB 切换折叠,造成延迟. 这项研究揭示了温度影响KaiB折叠切换,对于时钟温度补偿至关重要.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 系统生物学 系统生物学
背景情况:
- 蓝藻细菌的昼夜时钟使用由KaiB蛋白折叠切换驱动的后翻译振荡器.
- KaiB蛋白在稳定的基态折叠 (gsKaiB) 和不稳定的折叠切换折叠 (fsKaiB) 之间进行可逆过渡.
- 折叠切换事件在时钟的负反循环中引入了关键延迟.
研究的目的:
- 为了研究 KaiB 蛋白质折叠切换的温度依赖和机制.
- 了解温度如何影响KaiB折叠之间的稳定性和过渡率.
- 探索对昼夜时钟温度补偿的影响.
主要方法:
- 蛋白质折叠切换的实验分析.
- 对 KaiB 蛋白质动态的计算模拟.
- 原生状态的-交换NMR实验.
- 昼夜时钟振荡的动态建模.
主要成果:
- KaiB的基态折叠 (gsKaiB) 稳定性随着温度相对于折叠切换状态 (fsKaiB) 的增加.
- 对于gsKaiB → fsKaiB过渡的Q10值明显低于反向过渡.
- 折叠切换涉及未折叠的中间体,而proline异构化是一个速度限制的步骤.
- 通过温度补偿的动力模型来探索结果.
结论:
- 温度显著影响KaiB折叠切换动态,影响蓝藻细菌的昼夜时钟.
- 林异构化被确定为KaiB折叠切换中的关键速度限制步骤.
- 这些发现提供了关于昼夜节律中温度补偿机制的见解.
更多相关视频
10:38Monitoring Cell-autonomous Circadian Clock Rhythms of Gene Expression Using Luciferase Bioluminescence Reporters
Published on: September 27, 2012
22.4K
10:33Flexible Measurement of Bioluminescent Reporters Using an Automated Longitudinal Luciferase Imaging Gas- and Temperature-optimized Recorder ALLIGATOR
Published on: December 13, 2017
7.9K
相关概念视频
Circadian Rhythms and Gene Regulation
4.0K
The biological clock is involved in many aspects of regulating complex physiology in all animals. It was in 1935 when German zoologists, Hans Kalmus and Erwin Bünning, discovered the existence of circadian rhythm in Drosophila melanogaster. However, the internal molecular mechanisms behind the circadian clock remained a mystery until 1984, when Jeffrey C. Hall, Michael Rosbash, and Michael W. Young discovered the expression of the Per gene oscillating over a 24-hour cycle. In subsequent...
4.0K
Biological Clocks and Seasonal Responses
34.6K
The circadian—or biological—clock is an intrinsic, timekeeping, molecular mechanism that allows plants to coordinate physiological activities over 24-hour cycles called circadian rhythms. Photoperiodism is a collective term for the biological responses of plants to variations in the relative lengths of dark and light periods. The period of light-exposure is called the photoperiod.
34.6K
Calmodulin-dependent Signaling
5.1K
Calmodulin (CaM) is a calcium-binding protein in eukaryotes that controls various calcium-regulated cellular processes. It has four calcium-binding sites that bind calcium to form the calcium-calmodulin ( Ca2+-CaM) complex. GPCR stimulation increases the calcium levels in the cells that bind to CaM and induces a conformational change.
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
5.1K
Riboswitches
8.1K
Riboswitches are non-coding mRNA domains that regulate the transcription and translation of downstream genes without the help of proteins. Riboswitches bind directly to a metabolite and can form unique stem-loop or hairpin structures in response to the amount of the metabolite present. They have two distinct regions – a metabolite-binding aptamer and an expression platform.
The aptamer has high specificity for a particular metabolite which allows riboswitches to specifically regulate...
The aptamer has high specificity for a particular metabolite which allows riboswitches to specifically regulate...
8.1K
Molecular Chaperones and Protein Folding
17.9K
The native conformation of a protein is formed by interactions between the side chains of its constituent amino acids. When the amino acids cannot form these interactions, the protein cannot fold by itself and needs chaperones. Notably, chaperones do not relay any additional information required for the folding of polypeptides; the native conformation of a protein is determined solely by its amino acid sequence. Chaperones catalyze protein folding without being a part of the folded protein.
The...
The...
17.9K
Protein Complexes with Interchangeable Parts
2.5K
Groups of proteins may form a complex where each protein in this complex has a different role in the overall execution of the complex’s function. Often some of the proteins in the complex can be replaced by a closely related variant to give a complex that contains many of the same components yet is functionally distinct.
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order...
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order...
2.5K
