protein autoprocessing

Definition

Target type: biologicalprocess

Processing which a protein carries out itself. This involves actions such as the autolytic removal of residues to generate the mature form of the protein. [GOC:ai, PMID:9335337]

Protein autoprocessing is a crucial biological process in which a protein cleaves itself into two or more functional units. This self-catalyzed proteolytic event is driven by the protein's own enzymatic activity, often residing within a specific domain known as an "autocatalytic domain." Autoprocessing plays a pivotal role in regulating protein function, maturation, and activation. Here's a detailed breakdown of the process:

1. **Protein Synthesis:** The process begins with the synthesis of a precursor protein containing the autocatalytic domain. This precursor protein may be inactive or possess limited functionality.
2. **Autocatalytic Cleavage:** The autocatalytic domain within the precursor protein acts as an enzyme, specifically a protease, that cleaves itself at a defined site. This cleavage event separates the precursor protein into two or more distinct polypeptides.
3. **Functional Activation:** The autocatalytic cleavage often leads to the activation or maturation of one or both of the resulting polypeptides. For instance, the cleaved protein may acquire a new catalytic activity, become a more stable structure, or gain the ability to bind to specific targets.
4. **Protein Maturation:** In many cases, autoprocessing contributes to the maturation and stabilization of the protein. The cleavage event may remove unnecessary segments or expose functional domains.
5. **Regulation of Protein Function:** Autoprocessing serves as a key regulatory mechanism for controlling protein activity. By cleaving itself, the protein can switch between inactive and active states, responding to cellular signals or environmental cues.

Examples of protein autoprocessing abound in various biological systems:

- **Viral Proteases:** Autoprocessing is critical for the replication of many viruses. Viral proteases cleave viral polyproteins into individual proteins required for viral assembly and replication.
- **Insulin Processing:** Insulin is a peptide hormone produced by the pancreas. Its precursor, preproinsulin, undergoes autoprocessing to generate mature insulin.
- **Caspase Activation:** Caspases are cysteine proteases involved in apoptosis (programmed cell death). Caspase activation often involves autoprocessing events that trigger the cascade of apoptotic events.

Autoprocessing, therefore, is a fundamental biological process with diverse roles in protein function, regulation, and maturation. It is a testament to the intricate self-regulating mechanisms within living organisms.'
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Proteins (12)

Compounds (279)