[
Nat Cell Biol,
2005]
It has long been known that the mammalian small GTPase Rab5 is involved in clathrin-mediated endocytosis. However, most Rab5-interacting proteins are localized to endosomes rather than to the plasma membrane. A newly discovered nucleotide-exchange factor for Rab5 in Caenorhabditis elegans now provides the missing link for activating Rab5 at the plasma membrane.