Final answer:
The three common post-translational modifications to proteins are phosphorylation, glycosylation, and ubiquitination. These modifications regulate protein activity, interactions, stability, and degradation within the cell.
Step-by-step explanation:
Post-translational modifications (PTMs) are critical for altering the properties and functions of proteins after they have been translated from mRNA. There are several types of PTMs, but three common modifications include:
- Phosphorylation - The addition of phosphate groups to specific amino acids, such as serine, threonine, or tyrosine, which can affect protein activity, stability, and interaction with other proteins.
- Glycosylation - The attachment of sugar molecules to proteins which can influence their folding, stability, and interactions with other cellular components.
- Ubiquitination - The attachment of ubiquitin proteins to a target protein, often signaling it for degradation, but also impacting its cellular location or activity.
These modifications serve various functions, including the regulation of enzyme activity, protein-protein interactions, and determination of the lifespan of the protein within the cell.