E3 ubiquitin-protein ligase ligand of Numb-protein X 1 (LNX1)

E3 ubiquitin-protein ligase ligand of Numb-protein X 1 (LNX1) is a multi-domain membrane-associated enzyme characterized by a RING finger domain responsible for E3 ubiquitin ligase activity and several PDZ domains that mediate protein-protein interactions and scaffolding[1][2][4][3]. LNX1's principal function is to ubiquitinate and promote proteasomal degradation of selected substrates, most notably the cell fate determinant Numb, thus influencing pathways such as Notch signaling, asymmetric cell division, and differentiation[4][1][2]. It participates broadly in cellular signal transduction and is linked to key biological processes in neuronal signaling and cancer. Various isoforms of LNX1 exist, with some having scaffold roles independent of ubiquitin ligase activity[1][2]. Disease associations include cancer, neurodevelopmental disorders, and rare syndromes[3][1]. The full spectrum of its physiological effects and druggability remains under investigation.

Other names

Ligand of Numb-protein X 1LNXPDZRN2E3 ubiquitin-protein ligase LNXNumb-binding protein 1PDZ domain-containing RING finger protein 2RING-type E3 ubiquitin transferase LNX1Multi-PDZ-domain-containing proteinUNQ574/PRO1136

Inhibition or modulation of ubiquitin ligase activity (hypothetical mechanism—would block ubiquitination and degradation of targets such as Numb) Modulation of scaffold interactions (affect signal transduction by disrupting protein-protein interactions)