蛋白质酶凝聚物形成是由与穿因子和无处不在链的多价值相互作用驱动的
Kenrick A Waite1, Gabrielle Vontz1, Stella Y Lee1
1Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS 66160.
概括
蛋白质酶凝聚物通过泛素链和Rad23和Dsk2等穿因子形成,隔离泛素基质. 这一过程对于在压力和能量耗尽下细胞调节至关重要.
科学领域:
- 细胞生物学 细胞生物学
- 分子生物学分子生物学
- 生物化学 生物化学
背景情况:
- 压力条件诱导蛋白质体转移到酵母和哺乳动物细胞中的细胞凝聚物.
- 推动蛋白酶体凝聚物形成的分子相互作用仍然不太清楚.
研究的目的:
- 阐明了酵母体中蛋白质酶凝聚物形成的分子机制.
- 确定涉及压力诱导和自发蛋白酶体凝结的关键因素和相互作用.
主要方法:
- 研究了在酵母菌株中蛋白质酶凝聚物的形成,其中存在穿因子基因缺失 (Rad23,Dsk2,DDI1).
- 利用显微镜观察蛋白质体局部化和凝结物形成.
- 分析了在凝聚剂组合中泛素链和特定蛋白酶子单元 (Rpn1,Rpn10,Rpn13) 和穿因子域 (Ubl) 的作用.
主要成果:
- 在酵母体中形成蛋白质酶凝聚剂需要无素链和穿因子Rad23和Dsk2.
- 删除DDI1会导致自发的蛋白酶体凝聚物,与K48链接的泛素链的积累有关.
- 穿因子的蛋白质组和泛类 (Ubl) 域上的特定的泛素受体在各种条件下对凝结物形成至关重要.
结论:
- 提出了一个模型,其中长的K48连接的泛素链作为支架,促进蛋白质酶凝聚体组合的多价值相互作用.
- 蛋白质酶凝结物隔离不活的蛋白质酶和无处不在的基质,表明其作用超出了简单的存储,可能与细胞能量状态有关.
相关概念视频
01:13The Proteasome
835
Eukaryotic cells can degrade proteins through several pathways. One of the most important among these is the ubiquitin-proteasome pathway. It helps the cell eliminate the misfolded, damaged, or unwarranted cytoplasmic proteins in a highly specific manner.
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. This involves participation of a series of enzymes including— E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. This involves participation of a series of enzymes including— E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
835
01:17The Proteasome Structure
752
The ubiquitin-proteasome pathway is a well-known mechanism utilized by eukaryotic cells to remove cytoplasmic proteins that are misfolded, damaged, or no longer needed. In this pathway, the protein that needs to be eliminated undergoes a process called ubiquitination, where a chain of ubiquitin molecules is attached to the 48th lysine residue of the target protein. This ubiquitin modification helps the proteasome distinguish between a target protein and a healthy protein.
The proteasome is an...
The proteasome is an...
752
02:41Protein Complex Assembly
10.6K
Proteins can form homomeric complexes with another unit of the same protein or heteromeric complexes with different types. Most protein complexes self-assemble spontaneously via ordered pathways, while some proteins need assembly factors that guide their proper assembly. Despite the crowded intracellular environment, proteins usually interact with their correct partners and form functional complexes.
Many viruses self-assemble into a fully functional unit using the infected host cell to...
Many viruses self-assemble into a fully functional unit using the infected host cell to...
10.6K
01:25Protein Folding
8.0K
Proteins are chains of amino acids linked together by peptide bonds. Upon synthesis, a protein folds into a three-dimensional conformation, critical to its biological function. Interactions between its constituent amino acids guide protein folding, and hence the protein structure is primarily dependent on its amino acid sequence.
Protein Structure Is Critical to Its Biological Function
Proteins perform a wide range of biological functions such as catalyzing chemical reactions, providing...
Protein Structure Is Critical to Its Biological Function
Proteins perform a wide range of biological functions such as catalyzing chemical reactions, providing...
8.0K
03:00Molecular Chaperones and Protein Folding
18.0K
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...
18.0K
01:19Translocation of Proteins into the Mitochondria
3.1K
Mitochondrial precursors are translocated to the internal subcompartments via independent mechanisms involving distinct protein machineries called translocases.
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
3.1K