Ligand of numb-protein X 2 (LNX2)

Ligand of numb-protein X 2 (LNX2) is an E3 ubiquitin ligase, characterized by multiple PDZ domains and unique N- and C-terminal zinc finger motifs flanking its RING domain[1]. It is named for its ability to bind and ubiquitinate the cell fate determinant NUMB, thereby modulating NUMB/NOTCH signaling—a pathway central to neural development, synapse formation, and neuroglial function[1]. Beyond the nervous system, LNX2 is implicated in additional processes including osteoclast differentiation (bone metabolism), and possibly in carcinogenesis, particularly colorectal cancer[1][3]. The protein is also referred to as PDZRN1 in some literature. LNX2 acts via protein-protein interactions and ubiquitination, affecting the degradation or activity of key signaling molecules. No drugs or chemical inhibitors specific to LNX2 are currently reported, and its direct clinical utility as a biomarker or drug target is only emerging[1][3][5].

Other names

PDZRN1

Ubiquitination of target proteins (including NUMB and other synaptic proteins); Modulation of NOTCH pathway via NUMB degradation