Related Experiment Video
Updated: May 24, 2026
06:06
In Vitro Analysis of E3 Ubiquitin Ligase Function
Published on: May 14, 2021
Analysis of chaperone-assisted ubiquitylation
Michael Dreiseidler1, Niko Dick, Jörg Höhfeld
1Institut für Zellbiologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany.
Methods in Molecular Biology (Clifton, N.J.)
|February 22, 2012
Summary
Molecular chaperones, like Hsp70s, actively aid protein degradation, maintaining cellular balance. This study reconstitutes chaperone-assisted ubiquitylation to detail this proteostasis mechanism.
Area of Science:
- Cellular Biology
- Biochemistry
Background:
- Molecular chaperones, particularly 70-kDa heat shock proteins (Hsp70s), are increasingly recognized for their roles beyond protein folding.
- Hsp70s actively participate in protein degradation pathways, significantly contributing to maintaining protein homeostasis (proteostasis).
Purpose of the Study:
- To describe the in vitro reconstitution of chaperone-assisted ubiquitylation.
- To enable detailed molecular analysis of this crucial proteostasis mechanism.
Main Methods:
- In vitro reconstitution of chaperone-assisted ubiquitylation.
- Analysis of molecular details of ubiquitylation processes involving Hsp70s and ubiquitin ligases.
Main Results:
- Demonstration of successful in vitro reconstitution of chaperone-assisted ubiquitylation.
- Identification of key molecular interactions between Hsp70s, ubiquitin ligases, and client proteins in the degradation pathway.
Conclusions:
- Chaperone-assisted ubiquitylation is a vital mechanism for protein degradation and proteostasis.
- The reconstituted system provides a platform for further investigation into the molecular intricacies of chaperone-mediated protein turnover.
Related Concept Videos
03:00Molecular Chaperones and Protein Folding
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...
03:00Molecular Chaperones and Protein Folding
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...
02:04Covalently Linked Protein Regulators
Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein.
These groups modify specific amino acids in a protein.
02:58Regulated Protein Degradation
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...
01:13The Proteasome
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 (ubiquitin...
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 (ubiquitin...