信号序列激活了SRPRNA的催化开关
Niels Bradshaw1, Saskia B Neher, David S Booth
1Howard Hughes Medical Institute, 4000 Jones Bridge Road, Chevy Chase, MD 20815, USA.
概括
信号识别粒子RNA充当分子开关,控制蛋白质向膜. 它确保信号识别粒子-受体相互作用和GTPase活动对信号结合有反应.
科学领域:
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
- 蛋白质向定位是指蛋白质向定位.
背景情况:
- 信号识别粒子 (SRP) 途径将蛋白质向细胞膜.
- SRP 与其受体 (SR) 相互作用,以促进蛋白质转位.
- 在SRP-SR相互作用和GTPase活性中,SRPRNA起着催化作用.
研究的目的:
- 研究SRPRNA在SRP-SR相互作用中的调节作用.
- 了解SRPRNA的催化活性如何在蛋白质向过程中受到控制.
- 阐明SRPRNA将GTP水解与生产性蛋白向相结合的机制.
主要方法:
- 生物化学试验测量SRP-SR复合物的形成.
- GTPase活动测试.
- 分析SRPRNA在信号和洗剂的存在和缺席中的催化功能.
主要成果:
- SRP RNA的催化活性是构成性的,但只有当SRP与信号序列结合时,它才能加速SRP-SR复合体的形成.
- 一种常用的洗剂模仿信号,掩盖了这个调节步骤.
- SRP RNA 作为一个信号依赖分子开关而起作用.
结论:
- SRP RNA 集成了信号结与 SRP-SR GTPase 循环.
- 这种机制确保了蛋白质向与有效的GTP水解相结合.
- 在SRP路径中,SRPRNA起到关键的控制元素的作用,确保有效和准确的蛋白质传递到膜.
相关概念视频
Directing Proteins to the Rough Endoplasmic Reticulum
The organelle-specific signaling sequences direct proteins synthesized in the cytosol to their final destination like ER, mitochondria, peroxisomes, etc. Some of the proteins directed to ER are then trafficked via vesicles to other organelles within the cell or the extracellular environment through the Golgi complex. For example, the rough ER synthesizes soluble proteins for transportation to the lysosomes or secretion out of the cell. It can also synthesize transmembrane proteins that can...
Translational Regulation
Translational regulation in prokaryotes ensures efficient protein synthesis by controlling ribosome access to mRNA. This regulation is mediated by secondary RNA structures, including translational riboswitches, RNA thermometers, and small RNAs (sRNAs), which respond to intracellular and environmental signals to modulate gene expression.Translational RiboswitchesRiboswitches in the leader region of mRNAs can regulate translation by altering the accessibility of the Shine-Dalgarno (SD) sequence,...
Transcriptional Regulation: Riboswitches
Riboswitches are RNA elements that regulate gene expression by altering their secondary structures in response to specific effector molecules. These elements, located in the leader regions of certain mRNAs, act as transcriptional regulators by toggling between alternative conformations to control downstream gene expression. Riboswitch-mediated regulation is a precise mechanism for modulating biosynthetic pathways, as exemplified by the riboflavin biosynthesis pathway in Bacillus...
Riboswitches
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...
RNA Splicing
Splicing is the process by which eukaryotic RNA is edited before its translation into protein. The RNA strand transcribed from eukaryotic DNA is called the primary transcript. The primary transcripts that become mRNAs are called precursor messenger RNAs (pre-mRNAs). Eukaryotic pre-mRNA contains alternating sequences of exons and introns. Exons are nucleotide sequences that code for proteins, whereas introns are the non-coding regions. In RNA splicing, introns are removed and exons are bonded...
RNA Splicing
Splicing is the process by which eukaryotic RNA is edited before its translation into protein. The RNA strand transcribed from eukaryotic DNA is called the primary transcript. The primary transcripts that become mRNAs are called precursor messenger RNAs (pre-mRNAs). Eukaryotic pre-mRNA contains alternating sequences of exons and introns. Exons are nucleotide sequences that code for proteins, whereas introns are the non-coding regions. In RNA splicing, introns are removed and exons are bonded...


