protein maturation

Definition

Target type: biologicalprocess

Any process leading to the attainment of the full functional capacity of a protein. [GOC:ai]

Protein maturation is a complex and essential process that transforms newly synthesized polypeptide chains into functional proteins. This intricate journey involves a series of events, including folding, modification, and transport, each contributing to the final structure and activity of the protein. Here's a detailed overview:

1. Translation: The process begins with the synthesis of a polypeptide chain based on the genetic information encoded in mRNA. This nascent polypeptide chain emerges from the ribosome with a specific amino acid sequence, but it is generally unstructured and lacks biological activity.

2. Folding: The polypeptide chain undergoes a remarkable transformation, folding into a unique three-dimensional structure. This process is guided by the amino acid sequence and is influenced by interactions between amino acids, including hydrogen bonds, hydrophobic interactions, electrostatic interactions, and disulfide bonds. Chaperone proteins play a crucial role in assisting proper folding by preventing aggregation and promoting the formation of correct structures.

3. Modification: Once folded, proteins often undergo further modifications, which can significantly alter their properties and functions. These modifications include:

a. Glycosylation: The addition of sugar molecules (glycans) to specific amino acid residues, influencing protein stability, folding, and recognition.
b. Phosphorylation: The attachment of phosphate groups, often regulating protein activity by altering their conformation or interactions with other molecules.
c. Acetylation: The addition of acetyl groups, commonly found at the N-terminus of proteins, impacting their stability and interactions.
d. Ubiquitination: The attachment of ubiquitin molecules, a small protein that can target proteins for degradation or alter their localization and activity.

4. Transport: Newly synthesized proteins are often targeted to specific cellular compartments, such as the endoplasmic reticulum, Golgi apparatus, or other organelles. Transport is facilitated by chaperone proteins and specialized transport mechanisms.

5. Assembly: Some proteins require the assembly of multiple subunits to form functional complexes. These subunits fold individually and then associate through non-covalent interactions, leading to the formation of complex structures.

6. Degradation: Proteins have finite lifespans and are ultimately degraded through proteolytic pathways, ensuring the removal of damaged or misfolded proteins and maintaining cellular homeostasis. This process is often regulated by ubiquitination and involves specialized proteolytic complexes, such as the proteasome.'
"

Proteins (15)

Compounds (419)