posttranslasyonel

Posttranslasyonel refers to processes that occur after a protein has been synthesized from messenger RNA, a step known as translation. These modifications are crucial for the protein's final function, stability, localization within the cell, and interactions with other molecules.

One of the most common posttranslasional modifications is phosphorylation, where a phosphate group is added to the protein. This can act as a molecular switch, turning protein activity on or off. Glycosylation, the addition of carbohydrate chains, is another widespread modification, particularly important for proteins found on the cell surface or secreted from the cell, influencing their folding and recognition.

Other significant modifications include ubiquitination, which can mark a protein for degradation, and acetylation, which can affect gene expression and protein stability. Many proteins also undergo proteolytic cleavage, where a part of the protein is cut off, activating or modifying its function.

These posttranslasional modifications are highly regulated and occur in specific cellular compartments. They vastly increase the functional diversity of the proteome, allowing a limited number of genes to produce a much larger array of proteins with diverse roles. Errors in these processes can lead to various diseases.