Rabs of the Endosomal Recycling Pathway

The coordinated actions of the endosomal uptake and recycling pathways are one of the main cellular mechanisms for controlling the composition of the plasma membrane. Once endocytosed from the cell surface, proteins and membrane lipids typically undergo one of two fates. They can either be sent along the degradative pathway to lysosomes where they are broken down, or they are returned to the plasma membrane by the endosomal recycling pathway. Molecules that are recycled to the plasma membrane must undergo a complex series of sorting events, that occur in several organelles, prior to reaching their destination. Members of the Rab family of small GTPases are key regulators of this process.