Pószttranszlációs

Pószttranszláció, often shortened to PTM, refers to the set of chemical modifications that occur to a protein after its synthesis in the ribosome. This process is crucial for regulating a vast array of cellular functions. While translation produces the polypeptide chain, post-translational modifications fine-tune the protein's structure, activity, localization, and interactions with other molecules. These modifications are highly diverse and can include the addition of functional groups like phosphates, sugars, or lipids, as well as the cleavage of peptide bonds or the formation of disulfide bridges.

The types of PTMs are numerous, with phosphorylation being one of the most common and extensively studied. Glycosylation, the attachment of carbohydrate chains, plays a vital role in protein folding, stability, and cell-cell recognition. Ubiquitination, the addition of ubiquitin molecules, often targets proteins for degradation but can also mediate signaling pathways. Other significant modifications include methylation, acetylation, and hydroxylation, each conferring specific functional changes.

PTMs are dynamic and reversible in many cases, allowing cells to rapidly respond to internal and external stimuli. Enzymes called writers catalyze the addition of modifications, while erasers remove them, and readers recognize and bind to modified proteins, initiating downstream effects. Dysregulation of PTMs is implicated in numerous diseases, including cancer, neurodegenerative disorders, and metabolic diseases, highlighting their fundamental importance in maintaining cellular homeostasis. Understanding PTMs is therefore a key area of research in molecular biology and medicine.