The regulation and function of cullin-RING E3 ligases in cellular trafficking

The ubiquitin proteasome system (UPS) maintains cell homeostasis by the ubiquitin-mediated clearance of misfolded and damaged proteins, as well as modulation of proteins level in the cell, thus affecting various cell processes. Within the UPS, E3 ligases determine the specificity of substrates clearance, with cullin-RING E3 ligase (CRLs) representing the largest family of E3 ligases. CRLs regulate many vital cellular functions, including cell cycle, DNA damage response as well as cellular trafficking.

By utilizing GPS-ORFeome approach to monitor protein stability in a high throughput manner, we have discovered a number of CRLs substrates involved in protein trafficking. Hence, we focused our research on investigating CRLs regulation of trafficking using various molecular tools - we generated CRISPR/Cas9 knock-out cells to CRL complex components, coupled to microscopy approaches to monitor the protein levels and localization of the various substrates, as well as Electron microscopy (EM) to track changes in cell organelles and morphology.

Previous research has shown trafficking plays a central role in key cellular processes such as viral infection, nutrients intake and receptors recycling, alteration of these processes causes defects in signal transduction and pathologies. Thus, better understanding of trafficking regulation via the UPS system, may uncover new players regulating trafficking with implication for disease.