Linear Ubiquitin Chain Assembly Complex (LUBAC)

The linear ubiquitin chain assembly complex (LUBAC) is a unique multi-subunit E3 ubiquitin ligase complex. It is the only known enzyme capable of assembling linear (Met1-linked) polyubiquitin chains, a specific type of post-translational modification that plays critical roles in immune signaling and cell death regulation. LUBAC consists of three core protein subunits: HOIP (also known as RNF31), HOIL-1L and SHARPIN. Linear ubiquitination by LUBAC regulates several key cellular processes including NF-κB Activation, regulation of cell death and inflammasome activation.

LUBAC catalyzes the formation of linear/Met1-linked ubiquitin chains, modifying target proteins involved in NF-κB signaling, cell death pathways and inflammasome activation.