The protein degradation/ubiquitination pathway involves the regulated post-translational modification of substrate proteins via the addition of ubiquitin. Ubiquitination of substrate proteins signals the protein for degradation by the proteasome. Ubiquitination can also alter protein activity and interactions. The addition of ubiquitin is carried out by specific ubiquitin enzymes.
Figure 1. Protein ubiquitination is carried out by enzyme complexes such as ubiquitin-E1, ubiquitin-E2, and ubiquitin-E3. Once the protein has been tagged with ubiquitin, it is recognized for degradation by the proteasome. The proteasome degrades the substrate protein into peptide subunits. Click here to open a larger version of this image in a new window.
Genes Involved in the Pathway
- BTRC (ubiquitination-E3 ligase)
- ITCH (ubiquitination-E3 ligase)
- MDM2 (ubiquitination-E3 ligase)
- NEDD4L (ubiquitination-E3 ligase)
- PARK2 (ubiquitination-E3 ligase)
- UBA1 (ubiquitination-E1 ligase)
- UBE2D2 (ubiquitination-E2 ligase)
- UBR5 (ubiquitination-E3 ligase)
Last Updated: May 24, 2016