title: Kinetic activation of Rab8 guanine nucleotide exchange factor Rabin8 by Rab11.
abstract: The Rab family of small GTPases acts as molecular switches that control various stages of vesicular transport. Rab8 functions in exocytic trafficking from the trans-Golgi network (TGN) and recycling endosomes to the plasma membrane. Rabin8 is a major guanine nucleotide exchange factor (GEF) for Rab8. It activates Rab8 by catalyzing its GDP release for subsequent GTP loading. However, how Rabin8 itself is activated in cells is unclear. Recently, it was found that Rabin8 is a downstream effector of Rab11, which controls vesicle exit from the recycling endosomes. Rab11, in its GTP-bound form, stimulates the GEF activity of Rabin8. The Rab11-Rabin8-Rab8 interactions thus couple vesicle generation from the donor compartment to its delivery to plasma membrane. Here we describe the methods we used to express and purify several Rab proteins, and to assay for the effect of Rab11 in the kinetic activation of Rabin8 GEF activity.
authors: Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA, pennshan@gmail.com.
authors: Shanshan
authors: S
authors: Feng
authors: Bin
authors: B
authors: Wu
authors: Johan
authors: J
authors: Peränen
authors: Wei
authors: W
authors: Guo
mesh_terms: D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D009154:Mutation; D025941:Protein Interaction Mapping / Q000379:methods*; D020691:rab GTP-Binding Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D000099193:rab11 GTP-Binding Proteins
chemical_list: D020662:Guanine Nucleotide Exchange Factors; D020691:rab GTP-Binding Proteins; D000099193:rab11 GTP-Binding Proteins; C082377:RAB8A protein, human