Neuronal precursor cell expressed developmentally down-regulated 4 ligase (Nedd4-2) is a member of the HECT family E3 ubiquitin ligases, pivotal in the regulation of various ion channels, membrane receptors, and tumor suppressors. It catalyzes the transfer of ubiquitin from E2 ligase to specific targets, marking them for proteasomal degradation or endocytosis, thereby modulating numerous signaling pathways. Dysregulation of Nedd4-2 has been implicated in hypertension, kidney diseases, and tumor development, highlighting its potential as a therapeutic target. Nedd4-2 regulatory mechanisms involve autoinhibition, calcium binding, modulation of substrate specificity, and phosphorylation, which results in the binding of 14-3-3 proteins and subsequent changes in conformations (1-4). However, the structural mechanisms of these regulatory processes remain only poorly understood. Here, we present an integrative structural analysis that combines the cryoEM structure of Nedd4-2 with small-angle X-ray scattering (SAXS) data of the Nedd4-2/14-3-3 complex. This approach unveils the spatial organization of different domains within Nedd4-2 and offers insights into the architecture of the complex formed with 14-3-3 proteins. Understanding the structural intricacies of Nedd4-2 and its interaction with 14-3-3 not only sheds light on its regulatory mechanisms but also offer a new opportunities for targeted interventions aimed at restoring its function in pathological conditions.
This study was supported by the Czech Science Foundation (V.O., grant number: 23-04686S), the Czech Academy of Sciences (RVO: 67985823 of the Institute of Physiology), We acknowledge Cryo-electron microscopy and tomography core facility CEITEC MU of CIISB, Instruct-CZ Centre, supported by MEYS CR (LM2023042) and European Regional Development Fund-Project „UP CIISB“ (No. CZ.02.1.01/0.0/0.0/18_046/0015974).