蛋白二硫化异硫酶作为质细胞转化激活的调节剂
1Department of Cell Biology and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
Science (New York, N.Y.)
|January 7, 1998
概括
叶绿体中光调节的基因表达是由一种新的机制控制的. 一种蛋白质二硫化异构酶调节了质聚乙烯酸结合蛋白的化物.
科学领域:
- 植物生物学 植物生物学
- 分子生物学分子生物学
- 基因规则 基因规则
背景情况:
- 叶绿体信使RNAs (mRNAs) 的光调节翻译取决于结合5'非翻译区域 (UTR) 的因素.
- 叶绿体聚乙烯酸结合蛋白 (cPABP) 对于通过5'-UTR结合的psbAmRNA转化至关重要.
研究的目的:
- 研究调节cPABP与psbA mRNA 5'-UTR.结合的机制.
- 确定调节cPABP与mRNA相互作用的因素.
主要方法:
- 用cPABP.cPABP对质质蛋白进行联合净化.
- 对对cPABP结合的蛋白质二硫化异构酶活性进行分析.
- 研究cPABP-mRNA相互作用的氧化还原和酸化效应.
主要成果:
- 鉴定出一种质细胞局部化的蛋白质二硫化异硫酶.
- 这种酶调节cPABP与psbA mRNA 5'-UTR.的结合.
- 在cPABP的氧化还原状态的可逆变化调节其结合.
结论:
- 一个新型的氧化还原敏感开关控制了叶绿体基因表达.
- 蛋白二硫化异构酶活性提供了调节翻译启动的可逆机制.
相关概念视频
01:56Riboswitches
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...
01:24Protein Transport to the Stroma
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...
01:11Protein Transport to the Outer Chloroplast Membrane
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.
01:26Protein Modifications in the RER
Modification of secretory and transmembrane proteins entering the rough ER begins in the ER lumen. These modifications aid in protein folding and stabilize the acquired tertiary structure. Protein modifications in the rough ER co-occur at different stages of protein folding.
Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal sequences.
Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal sequences.
01:18Protein Transport to the Inner Chloroplast Membrane
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...
01:29Translational 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,...