Ubikitiinilaatio
Ubikitiinilaatio, also known as ubiquitination, is a crucial post-translational modification that involves the covalent attachment of ubiquitin, a small regulatory protein, to a target protein. This process is highly conserved across eukaryotes and plays a fundamental role in a wide array of cellular functions. Ubiquitin is attached to lysine residues on the substrate protein, typically through a cascade of enzymatic reactions involving three main types of enzymes: ubiquitin-activating enzymes (E1s), ubiquitin-conjugating enzymes (E2s), and ubiquitin ligases (E3s). E1 enzymes activate ubiquitin, E2 enzymes facilitate the transfer of activated ubiquitin to the substrate, and E3 ligases provide specificity by recognizing the target protein and mediating the final transfer.
The consequences of ubiquitination are diverse and depend on the nature of the ubiquitin chain formed. Monoubiquitination,