Final Report Summary - ARCID (The Role of Arl Proteins in Retinal and other Ciliary Diseases)
The ARCID project asked the question of how proteins are selected for and transported into a compartment of the cell called a Cilium, a microbtubule-based extension of the cell surrounded by the membrane. The project unravelled how membrane-associated prenylated and myristoylated protein are transported by certain carrier molecules and how they are released by the Arf-related GTP-binding proteins. It was shown that one these molecular switches, Arl3, is activated by a factor called GEF localized exclusively inside the cilium. It is kept inactive in the rest of the cell by an inactivator molecule called GAP. This creates a gradient of activity across the ciliary gate which very much resembles the mechanism of transport into the nucleus regulated by another GTP-binding protein called Ran