posttranslatsiooniliste

Posttranslational modifications (PTMs) are chemical alterations that occur on proteins after their synthesis, during or after translation. These modifications play crucial roles in various cellular processes, including protein folding, stability, localization, and function. PTMs can be reversible or irreversible, and they can occur on different amino acid residues, such as serine, threonine, tyrosine, cysteine, lysine, and arginine.

Common PTMs include phosphorylation, glycosylation, ubiquitination, and acetylation. Phosphorylation, for example, involves the addition of a phosphate group to serine, threonine, or tyrosine residues and is often regulated by protein kinases and phosphatases. Glycosylation adds sugar molecules to proteins, which can occur co-translationally or posttranslationally. Ubiquitination attaches ubiquitin molecules to lysine residues, typically targeting proteins for degradation or other cellular responses. Acetylation adds an acetyl group to lysine residues and is often associated with gene regulation and chromatin structure.

PTMs are essential for cellular signaling, cell cycle regulation, and various physiological processes. Dysregulation of PTMs has been linked to numerous diseases, including cancer, neurodegenerative disorders, and metabolic conditions. Understanding the mechanisms and functions of PTMs is therefore vital for advancing our knowledge of cellular biology and developing therapeutic strategies for various diseases.