E3 Enzymes (Ubiquitin ligases)

E3 enzymes, also known as ubiquitin ligases, are specialized proteins that help regulate cell functions by marking other proteins for destruction or modification. They do this by attaching a small molecule called ubiquitin to target proteins, signaling them for degradation or altering their activity. E3s are crucial because they recognize specific proteins and ensure they are modified accurately, maintaining cellular health and balance. Their activity influences processes like cell cycle progression, signal transduction, and responses to stress. Dysfunction in E3 enzymes can lead to diseases such as cancer and neurodegenerative disorders.