Related Experiment Video
Updated: May 28, 2026
09:00
Comparative Strategies for Ubiquitination Detection in Mammalian Cell Lysates Using SMAD2/SMURF2 as a Model
Published on: April 17, 2026
Cellular strategies for making monoubiquitin signals
Harish N Ramanathan1, Yihong Ye
1Laboratory of Molecular Biology, National Institute of Diabetes and Digestive, and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Critical Reviews in Biochemistry and Molecular Biology
|October 11, 2011
Summary
This study explores how cells generate monoubiquitination, a key protein modification. Understanding these mechanisms is crucial for deciphering cellular processes and potential therapeutic targets.
Area of Science:
- Molecular Biology
- Cellular Biology
- Biochemistry
Background:
- Post-translational modification by ubiquitin regulates diverse eukaryotic cellular processes.
- Ubiquitin conjugation occurs as single moieties (monoubiquitination) or linked chains (polyubiquitination), forming distinct signals.
- Monoubiquitination is vital for gene transcription, protein trafficking, and DNA repair, yet its production mechanisms remain unclear.
Purpose of the Study:
- To elucidate the cellular strategies responsible for generating monoubiquitinated proteins.
- To highlight the importance of understanding monoubiquitin signal production.
Main Methods:
- Review and discussion of established principles in protein ubiquitination.
- Analysis of well-characterized examples of monoubiquitinated proteins.
- Exploration of potential mechanisms for restricting ubiquitin chain elongation.
Main Results:
- Identified key strategies for producing monoubiquitinated proteins.
- Proposed mechanisms include low-affinity ubiquitin binding, specialized E2 conjugating enzymes, and restricted chain elongation.
- These principles may extend to ubiquitin-like proteins (UBLs).
Conclusions:
- The mechanisms for generating monoubiquitin signals are diverse and critical for cellular function.
- Further research into these strategies will illuminate fundamental biological processes.
- Understanding monoubiquitination is essential for advancing molecular and cellular biology.
Related Concept Videos
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...
01:15Receptor Downregulation in MVBs
Multivesicular bodies (MVBs) are mature endosomes that sort ubiquitinated proteins and then fuse with lysosomes to degrade the sorted proteins. Epidermal growth factor (EGF) and its receptor (EGFR) form a complex that can be internalized through endocytosis, sorted into an MVB, and later degraded.
The EGFR can initiate signaling pathways that lead to cell proliferation, migration, and differentiation. Overexpression of EGFR stimulates cells to proliferate. Excessive EGFR activation may...
The EGFR can initiate signaling pathways that lead to cell proliferation, migration, and differentiation. Overexpression of EGFR stimulates cells to proliferate. Excessive EGFR activation may...
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.
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...
02:18The Proteasome
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...
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...
01:38Intralumenal Vesicles and Multivesicular Bodies
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...