Ubiquitin
Ubiquitin — A small 76-amino acid regulatory protein that tags other proteins for degradation via the proteasome, central to protein quality control research.
What Is Ubiquitin?
Ubiquitin is a highly conserved 76-amino acid peptide (MW: 8565 Da) found in all eukaryotic cells. It functions as a post-translational tag: when covalently attached to target proteins through an isopeptide bond between ubiquitin's C-terminal glycine and a target lysine, it signals for proteasomal degradation, alters protein localization, or modifies protein activity.
The Ubiquitin-Proteasome System
- E1 (activating): ATP-dependent activation of ubiquitin's C-terminus
- E2 (conjugating): Transfers activated ubiquitin to the E3 ligase
- E3 (ligating): >600 human E3 ligases provide target selectivity. The druggable step
- 26S proteasome: Degrades polyubiquitinated proteins into small peptide fragments
Drug Development
PROTAC (proteolysis-targeting chimera) technology uses bifunctional molecules with a peptide-based E3 ligase-recruiting moiety to redirect the ubiquitin system to degrade disease-causing proteins, representing a frontier in peptide-inspired drug discovery.
Frequently Asked Questions
What is Ubiquitin?
A small 76-amino acid regulatory protein that tags other proteins for degradation via the proteasome, central to protein quality control research.
Why is Ubiquitin important in peptide research?
Ubiquitin is a fundamental concept in compound as it relates to peptide science. It directly influences experimental design, compound characterization, and the reliability of research outcomes across biochemistry and molecular biology disciplines.