potranslacyjna

Post-translational modification refers to the chemical alteration of a protein after its synthesis by ribosomes. These modifications are crucial for a protein's function, stability, localization, and interaction with other molecules. They can occur at various amino acid residues within the protein chain and can be reversible or irreversible.

Common post-translational modifications include phosphorylation, glycosylation, ubiquitination, acetylation, methylation, and proteolytic cleavage. Phosphorylation, the addition of a phosphate group, often acts as a molecular switch, activating or deactivating protein function. Glycosylation, the attachment of sugar molecules, plays a role in protein folding, stability, and cell-cell recognition. Ubiquitination, the tagging of a protein with ubiquitin, typically marks it for degradation. Acetylation and methylation can influence gene expression and protein-protein interactions. Proteolytic cleavage involves the cutting of a protein chain, often to activate it or to generate smaller functional fragments.

These modifications can significantly expand the functional repertoire of the proteome, allowing a limited number of genes to produce a vast array of proteins with diverse roles. Errors in post-translational modification can lead to various diseases, highlighting their importance in maintaining cellular homeostasis. The study of post-translational modifications, known as the "post-translational code," is a rapidly evolving field in molecular biology and biochemistry.