相关实验视频
Updated: May 3, 2026
06:09
An In Ovo Model for Testing Insulin-mimetic Compounds
Published on: April 23, 2018
11.5K
与核糖体相关的E3泛素酶在蛋白质质量控制中的作用
Mario H Bengtson1, Claudio A P Joazeiro
1Department of Cell Biology, The Scripps Research Institute, CB168, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
Nature
|September 14, 2010
概括
核细胞使用Ltn1泛素联酶消除异常蛋白质,该联酶针对不间断信使RNA (mRNA) 产品进行降解. 这一发现揭示了酵母中关键的蛋白质质量控制途径,并对神经退行性疾病有影响.
科学领域:
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
- 生物化学 生物化学
背景情况:
- 缺乏停止编码子的不间断信使RNA (mRNA) 可能是基因表达错误的结果,导致潜在有害的异常蛋白质.
- 细菌利用tmRNA (转移信使RNA) 进行这些不间断蛋白的共同翻译标记和降解.
- 欧核生物无休止蛋白质清除的机制在很大程度上是未知的.
研究的目的:
- 阐明真核细胞识别和消除不间断蛋白质的机制.
- 为了研究Ltn1 E3泛素酶在这种细胞过程中的作用.
主要方法:
- 研究了Saccharomyces cerevisiae Ltn1的功能,这是一个RING-domain类型的E3泛素酶.
- 研究了Ltn1与核糖体的关联.
- 分析了新生的不间断蛋白质的无处不在及其随后的蛋白质体降解.
主要成果:
- Ltn1主要与核糖体和无处不在的新生不间断蛋白质有关.
- 这种无处不在标志着无休止蛋白质的蛋白质体降解.
- Ltn1介导的无处不在是由在翻译的多分子尾巴期间的核糖体停滞触发的.
- 失去Ltn1功能会增加对因不间断的蛋白质积累而产生的压力的敏感性.
结论:
- Ltn1是真核生物无休止蛋白质质量控制的关键组成部分,类似于细菌的tmRNA.
- 这一途径涉及核糖体关联和无处不在,用于蛋白质酶体降解.
- 缺陷的Ltn1功能可能会导致在Listerin突变小鼠中观察到的神经退行性表型.
相关概念视频
02:58Regulated Protein Degradation
6.6K
It is vital to regulate the activity of enzymatic as well as non-enzymatic proteins inside the cell. This can be achieved either through creating a balance between their rate of synthesis and degradation or regulating the intrinsic activity of the protein. Both these regulation mechanisms play an essential role in the normal functioning of cells.
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
6.6K
01:58Cell Specific Gene Expression
13.3K
Multicellular organisms contain a variety of structurally and functionally distinct cell types, but the DNA in all the cells originated from the same parent cells. The differences in the cells can be attributed to the differential gene expression. Liver cells, whose functions include detoxification of blood, production of bile to metabolize fats, and synthesis of proteins essential for metabolism, must express a specific set of genes to perform their functions. Gene expression also varies with...
13.3K
01:45Regulation of Nuclear Protein Sorting
2.5K
Nuclear protein sorting regulates nucleus composition and gene expression, crucial for determining the fate of a eukaryotic cell. Hence, the entry and exit of molecules across the nuclear envelope is a tightly controlled process. Nuclear protein sorting can be inhibited by one of the following ways: 1) masking cargo signal sequences, 2) modifying the nuclear receptor's affinity for cargo, 3) controlling the nuclear pore size, 4) retaining the cargo during its transit to the cytosol or the...
2.5K
01:26Protein Modifications in the RER
5.6K
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...
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...
5.6K
01:29Protein Folding Quality Check in the RER
4.4K
ER is the primary site for the maturation and folding of soluble and transmembrane secretory proteins. The calnexin cycle is a specific chaperone system that folds and assesses the confirmation of N-glycosylated proteins before they can exit the ER lumen. The primary players of this quality check pipeline are the lectins, ER-resident chaperones, and a glucosyl transferase enzyme. In case the calnexin system in the lumen fails to salvage a misfolded protein, it is transported to the cytoplasm...
4.4K
01:26Bacterial Protein Maturation
744
Bacterial protein maturation is a tightly regulated process that ensures newly synthesized polypeptides achieve correct functional conformations. This maturation involves a series of modifications, folding events, and quality control steps, often assisted by specialized chaperone proteins.N-Terminal ModificationsThe maturation of bacterial polypeptides begins cotranslationally as the polypeptide exits the ribosome. The first amino acid, N-formylmethionine (fMet), is typically modified at the...
744