Abstract

Monitoring the Intracellular Trafficking of Secretory Proteins by the Retention using Selective Hooks (RUSH) System

Elaine Nery, Platform Manager, Institut Curie

In human cells, a large number of proteins are addressed to the cell surface using the secretory pathway. Among these proteins, some are responsible for human diseases, for example when their secretion is deregulated or when their presence at the cell surface facilitates pathological processes. Inhibiting the trafficking of such proteins toward the cell surface is an interesting therapeutic approach. The recently developed secretory assay, the RUSH system, enables to pulse and monitor the trafficking of virtually any protein of interest. As a proof of concept, we screened for molecules able to perturb the trafficking of the glycosylation enzyme Mannosidase II from the endoplasmic reticulum to the Golgi. Following screening of about 1000 chemical compounds, identified molecules were the submitted to serial dilutions to establish IC50 for their effects on Golgi integrity and trafficking. We are currently further using the RUSH assay in high content screening. Our aim is to identify molecules inhibiting the transport to the cell surface of proteins responsible for diseases, such as TNF involved in inflammatory diseases or CCR5, a co-receptor for the entry of HIV in cells, opening new therapeutic windows.