E3ubiquitinligas
E3 ubiquitin ligases are enzymes in the ubiquitin–proteasome system that catalyze the transfer of ubiquitin to target proteins. By tagging substrates with ubiquitin, they regulate protein stability, signaling, and localization, influencing numerous cellular processes. E3 ligases confer substrate specificity in the ubiquitination cascade, working alongside ubiquitin-activating enzymes (E1) and ubiquitin-conjugating enzymes (E2).
Most ubiquitination is carried out by three broad classes of E3 ligases: RING-type, HECT-type, and RBR-type. In
E3 ligases regulate essential cellular functions including cell cycle progression, DNA repair, and immune responses. Dysregulation
Overall, E3 ubiquitin ligases represent a large and diverse family that controls proteostasis and cellular signaling,