Multifaceted role of the ubiquitin ligase Itch in immune regulation.

The HECT-type E3 ligase Itch is increasingly being shown to have a vital role in immune regulation. Itch deficiency leads to deleterious inflammatory disorders both in mice and humans. By adding ubiquitin to the key signaling intermediates, Itch functions as a critical regulator of lymphocyte-cell activation, differentiation and immune tolerance. Also, Itch cooperates with deubiquitinating enzymes such as A20 and Cyld to terminate NF-κB signaling and prevent chronic inflammation. This review summarizes recent advances that highlight Itch's role in lymphocyte function and explores recent insights regarding its role as a regulator of inflammatory signaling.