protein K29-linked deubiquitination

Definition

Target type: biologicalprocess

A protein deubiquitination process in which a K29-linked ubiquitin chain, i.e. a polymer of ubiquitin formed by linkages between lysine residues at position 29 of the ubiquitin monomers, is removed from a protein. [GOC:bf]

K29-linked deubiquitination is a specific type of deubiquitination that involves the removal of ubiquitin chains from proteins, where the ubiquitin monomers are linked via their lysine 29 residues. This process plays a critical role in regulating diverse cellular processes, including signal transduction, protein degradation, and DNA repair.

Here's a detailed breakdown of the process:

1. **Ubiquitin Chain Formation:** K29-linked ubiquitin chains are assembled through a stepwise process involving the action of E1, E2, and E3 enzymes.
- **E1 (Ubiquitin Activating Enzyme):** Activates ubiquitin by attaching it to itself through a high-energy thioester bond.
- **E2 (Ubiquitin Conjugating Enzyme):** Accepts ubiquitin from E1 and transfers it to an E3 ligase.
- **E3 (Ubiquitin Ligase):** Recognizes specific substrate proteins and facilitates the attachment of ubiquitin chains to them. The E3 ligase determines the type of ubiquitin linkage, in this case, K29.

2. **K29-linked Deubiquitination:** The removal of K29-linked ubiquitin chains is catalyzed by specific deubiquitinases (DUBs).
- **DUBs:** These enzymes possess catalytic domains that cleave the isopeptide bond between the ubiquitin chain and the substrate protein or between ubiquitin monomers within the chain.
- **Specificity:** DUBs exhibit substrate and linkage specificity, with some DUBs preferentially targeting K29-linked ubiquitin chains.

3. **Regulation of Cellular Processes:** K29-linked deubiquitination plays a crucial role in regulating a variety of cellular processes, including:
- **Signal transduction:** K29-linked ubiquitination and deubiquitination can modulate the activity of signaling proteins, controlling the activation or inhibition of downstream pathways.
- **Protein degradation:** K29-linked ubiquitination can target proteins for degradation by the proteasome, while deubiquitination can rescue proteins from degradation.
- **DNA repair:** K29-linked ubiquitination is involved in DNA repair pathways, contributing to the stability and proper repair of damaged DNA.

4. **Dysregulation and Disease:** Dysregulation of K29-linked deubiquitination has been implicated in various diseases, including cancer, neurodegenerative disorders, and inflammatory diseases. For instance, aberrant deubiquitination of tumor suppressor proteins can contribute to cancer development.

In summary, K29-linked deubiquitination is a complex and highly regulated process involving specific enzymes that control the assembly and disassembly of K29-linked ubiquitin chains. This process is critical for maintaining cellular homeostasis and ensuring the proper functioning of diverse cellular processes.'
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Proteins (1)

Compounds (1)