protein repair

Definition

Target type: biologicalprocess

The process of restoring a protein to its original state after damage by such things as oxidation or spontaneous decomposition of residues. [GOC:mlg]

Protein repair is an essential cellular process that maintains the integrity and functionality of proteins. It encompasses a diverse range of mechanisms that address various types of protein damage, including misfolding, aggregation, and chemical modifications. The repair process aims to restore damaged proteins to their native state, preventing their degradation and dysfunction.

**1. Molecular Chaperones:** These proteins assist in proper protein folding, preventing aggregation and promoting correct conformation. They bind to unfolded or misfolded proteins, stabilizing them and facilitating their correct folding. Examples include Hsp70, Hsp90, and chaperonins.

**2. Protein Disulfide Isomerase (PDI):** This enzyme catalyzes the formation and breakage of disulfide bonds within proteins. It helps proteins fold correctly by facilitating the rearrangement of disulfide bonds, ensuring the proper formation of tertiary structures.

**3. Proteasome:** This multi-protein complex is responsible for degrading misfolded or damaged proteins. It recognizes and unfolds target proteins, breaking them down into peptides that can be recycled or eliminated.

**4. Ubiquitin Proteasome System (UPS):** This system involves the attachment of ubiquitin molecules to target proteins, tagging them for proteasomal degradation. Ubiquitination serves as a signal for the proteasome to recognize and degrade misfolded proteins, ensuring their removal from the cell.

**5. Autophagy:** This cellular process involves the engulfment and degradation of damaged organelles and proteins within membrane-bound vesicles called autophagosomes. Autophagy provides a mechanism for removing large protein aggregates or damaged components, maintaining cellular integrity.

**6. DNA Repair Mechanisms:** Errors in DNA replication or damage to DNA can lead to the production of defective proteins. DNA repair mechanisms correct these errors, ensuring the fidelity of protein synthesis and preventing the accumulation of misfolded proteins.

**7. Enzyme-Catalyzed Repair:** Certain enzymes can directly repair specific types of protein damage. For example, DNA glycosylases remove damaged bases from DNA, preventing the synthesis of faulty proteins.

**8. Oxidative Stress Response:** Oxidative stress can damage proteins by introducing reactive oxygen species (ROS). Cells possess specific mechanisms to combat oxidative stress and repair oxidized proteins. These mechanisms include enzymes like glutathione peroxidase and catalase, which neutralize ROS and protect proteins from oxidative damage.

Overall, protein repair is a complex and multifaceted process that involves numerous cellular mechanisms working in concert. These processes ensure the maintenance of protein integrity, preventing cellular dysfunction and promoting cellular homeostasis.'
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Proteins (2)

Compounds (2)