Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

The Proteasome02:18

The Proteasome

7.8K
Eukaryotic cells can degrade proteins through several pathways. One of the most important amongst 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. A series of enzymes carry out the ubiquitination of the target proteins - E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
7.8K
Regulated Protein Degradation02:58

Regulated 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...
6.6K
Intralumenal Vesicles and Multivesicular Bodies01:38

Intralumenal Vesicles and Multivesicular Bodies

4.0K
Intraluminal vesicles (ILVs) are small vesicles 50-80 nm in diameter formed during the maturation of early endosomes. A specialized endosome containing numerous ILVs is called a multivesicular body (MVB). ILVs contain internalized molecules such as antigens, nucleic acids, proteins, and metabolites. Some of these molecules are released from the MVBs inside exosomes and are transported to other cells. Other MVBs contain molecules that are retained in the ILVs and are later degraded within the...
4.0K
Export of Misfolded Proteins out of the ER01:32

Export of Misfolded Proteins out of the ER

4.3K
After folding, the ER assesses the quality of secretory and membrane proteins. The correctly folded proteins are cleared by the calnexin cycle for transport to their final destination, while misfolded proteins are held back in the ER lumen. The ER chaperones attempt to unfold and refold the misfolded proteins but sometimes fail to achieve the correct native conformation. Such terminally misfolded proteins are then exported to the cytosol by ER-associated degradation or ERAD pathway for...
4.3K
The Proteasome01:13

The Proteasome

1.6K
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...
1.6K
The Proteasome Structure01:17

The Proteasome Structure

2.2K
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...
2.2K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Systemic degradation of repressive transcription factors gates gene expression and cell fate specification.

bioRxiv : the preprint server for biology·2026
Same author

Exosomes in inflammatory tissue injury: key pathogenic factors and promising therapeutic agents.

Frontiers in immunology·2026
Same author

Localized heme sensing through a ternary molecular glue.

bioRxiv : the preprint server for biology·2026
Same author

Endoplasmic reticulum (ER) ubiquitin ligases: substrate recognition and emerging cellular functions.

Trends in cell biology·2026
Same author

Nuclear export modulates TDP-43 phase transition and cytoplasmic aggregation.

bioRxiv : the preprint server for biology·2026
Same author

Deep Learning-Guided Discovery of Dual Inhibitors of SARS-CoV-2 Entry and 3CL Protease.

Molecules (Basel, Switzerland)·2026
Same journal

Single-cell evidence for PANoptosome complexes.

Nature reviews. Molecular cell biology·2026
Same journal

Reply to 'Single-cell evidence for PANoptosome complexes'.

Nature reviews. Molecular cell biology·2026
Same journal

Plucking cellular ribosomes with Ribo-Tweezer.

Nature reviews. Molecular cell biology·2026
Same journal

COPII meets autophagy at the ER membrane.

Nature reviews. Molecular cell biology·2026
Same journal

Diapause presses pause on life's developmental and ageing clock.

Nature reviews. Molecular cell biology·2026
Same journal

Histone acetylation at the dawn of gene regulation.

Nature reviews. Molecular cell biology·2026
See all related articles

Related Experiment Video

Updated: May 5, 2026

In Vitro Ubiquitination and Deubiquitination Assays of Nucleosomal Histones
11:36

In Vitro Ubiquitination and Deubiquitination Assays of Nucleosomal Histones

Published on: July 25, 2019

10.6K

Building ubiquitin chains: E2 enzymes at work.

Yihong Ye1, Michael Rape

  • 1Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, Maryland 20892, USA. yihongy@mail.nih.gov

Nature Reviews. Molecular Cell Biology
|October 24, 2009
PubMed
Summary
This summary is machine-generated.

Ubiquitin chains modify proteins, altering their function. Ubiquitin-conjugating enzymes (E2s) are key mediators, controlling ubiquitin chain assembly, elongation, and topology for protein modification outcomes.

More Related Videos

In Vitro Analysis of E3 Ubiquitin Ligase Function
06:06

In Vitro Analysis of E3 Ubiquitin Ligase Function

Published on: May 14, 2021

5.3K
Evaluation of Substrate Ubiquitylation by E3 Ubiquitin-ligase in Mammalian Cell Lysates
09:47

Evaluation of Substrate Ubiquitylation by E3 Ubiquitin-ligase in Mammalian Cell Lysates

Published on: May 10, 2022

2.4K

Related Experiment Videos

Last Updated: May 5, 2026

In Vitro Ubiquitination and Deubiquitination Assays of Nucleosomal Histones
11:36

In Vitro Ubiquitination and Deubiquitination Assays of Nucleosomal Histones

Published on: July 25, 2019

10.6K
In Vitro Analysis of E3 Ubiquitin Ligase Function
06:06

In Vitro Analysis of E3 Ubiquitin Ligase Function

Published on: May 14, 2021

5.3K
Evaluation of Substrate Ubiquitylation by E3 Ubiquitin-ligase in Mammalian Cell Lysates
09:47

Evaluation of Substrate Ubiquitylation by E3 Ubiquitin-ligase in Mammalian Cell Lysates

Published on: May 10, 2022

2.4K

Area of Science:

  • Biochemistry
  • Molecular Biology
  • Cellular Biology

Background:

  • Protein ubiquitylation is a crucial post-translational modification.
  • Ubiquitylation involves ubiquitin-activating enzymes (E1s), ubiquitin-conjugating enzymes (E2s), and ubiquitin ligases (E3s).
  • The precise role of E2 enzymes in mediating ubiquitylation outcomes is an area of active research.

Purpose of the Study:

  • To highlight the central role of E2 enzymes in ubiquitin chain assembly.
  • To elucidate how E2 enzymes regulate the dynamics of ubiquitin chain formation.
  • To underscore the impact of E2-mediated chain architecture on protein function.

Main Methods:

  • Review of existing literature on ubiquitylation pathways.
  • Analysis of enzymatic mechanisms governing E2 activity.
  • Comparative study of different E2 enzyme functions in chain assembly.

Main Results:

  • E2 enzymes are critical for initiating and elongating ubiquitin chains.
  • E2s control the processivity and topology of assembled ubiquitin chains.
  • The specific chain architecture dictated by E2s determines downstream cellular consequences.

Conclusions:

  • E2 enzymes are master regulators of ubiquitin chain assembly.
  • Understanding E2 function is key to deciphering ubiquitylation signaling.
  • Targeting E2s may offer novel therapeutic strategies for diseases involving protein modification.