Abstract
Intracellular proteolysis in eukaryotes is primarily mediated by the Ubiquitin Proteasome System (UPS), which operates through the cascading action of three enzymes: E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3 (ubiquitin ligases). These enzymes are essential in this process as they recognize and transfer ubiquitin to target substrates. Intracellular proteol…