Deciphering the principles governing robust targeting of proteins to organelles

Descrizione del progetto

Capire la logica alla base della logistica delle proteine della natura

La cellula è spesso paragonata a una fabbrica e la logistica del trasporto delle proteine è sicuramente complessa. Si immagini una moltitudine di operai in un reparto produzione che deve smistare migliaia di diversi tipi di prodotti, appena usciti dalla catena di montaggio, per garantire che raggiungano le loro destinazioni corrette (o organuli, in questo caso) per poi essere utilizzati nel loro lavoro quotidiano. Ogni operaio deve determinare con esattezza verso quale destinazione deve recarsi il carico, ma deve farlo sulla base di pochissimi segnali altamente confusi e quindi conseguentemente trasportare il carico proteico. Nella cellula, migliaia di tali carichi proteici devono essere ordinati nei loro organuli, in ogni cellula e ogni minuto. Un solo passo sbagliato e l’intera cellula può morire, portando a malattia. Il progetto OnTarget, finanziato dall’UE, chiarirà come viene controllata la localizzazione delle proteine, con grandi vantaggi per la nostra comprensione dei processi naturali, così come per le terapie e i processi industriali.

Obiettivo

Half of eukaryotic proteins require targeting to specific organelles to execute their function. Research from multiple labs, including our own, has uncovered some of the pathways that recognize such cargo proteins and target them in an efficient and regulated fashion. However, many central pathways are clearly still missing. Importantly, current studies tend to focus on single cargo proteins and how they utilize one particular targeting pathway, creating an over-simplified view of the cellular road map. In the cell, multiple pathways provide overlapping or competing targeting options for thousands of cargo. Hence, various mechanisms exist to ensure robust but flexible sorting according to cellular needs. Naturally, a big challenge in the field is to understand how this complex network of targeting pathways is coordinated in a live cell during changing conditions.
The new tools and approaches that we will create during OnTarget will put us finally in the position to study the whole cellular targeting network and the interplay between its components. Specifically, we will uncover missing targeting pathways (Aim 1); develop techniques to map cargo range for targeting pathways in various environments (Aim 2); and develop an in-cellulo competition assay to define the rules that prioritize the delivery of one cargo over another across conditions (Aim 3). By creating cutting-edge systematic tools that track targeting in live cells as well as by comparing and contrasting multiple pathways and destinations, we will define the rules governing optimal wiring of the targeting network, allowing us to gain a comprehensive view of this process in a cellular context. Our work will unlock the door to full control over protein localization for basic research, as well as for medicine and industry. More broadly, the methodologies that we develop here will provide a platform for addressing any complex biological process that revolves around multiple, overlapping and competing, pathways