What does RAB GTPase do?
Rab GTPases control all aspects of intracellular vesicle trafficking by acting as regulatable switches that recruit effector molecules when in their active GTP-bound form. There are approximately 60 different Rab GTPases in humans that are associated with distinct intracellular membranes.
How do Rab proteins work?
Rab GTPases regulate many steps of membrane trafficking, including vesicle formation, vesicle movement along actin and tubulin networks, and membrane fusion. These processes make up the route through which cell surface proteins are trafficked from the Golgi to the plasma membrane and are recycled.
How is Rab activated?
After prenylation, the Rab can be delivered to a target membrane, where it is activated by a guanine nucleotide exchange factor (GEF) that catalyzes the exchange of bound GDP by GTP.
What does Rab stand for protein?
Ras-associated binding
Ras-associated binding (Rab) proteins are small GTPases of the Ras superfamily that continuously cycle between the cytosol and different membranes. In 2002, Pfeffer described 20 different Rab GTPases that have been identified as prenylated proteins localized in distinct membrane-bound compartments [25].
How many Rab proteins are there?
The Rab family is part of the Ras superfamily of small GTPases. There are at least 60 Rab genes in the human genome, and a number of Rab GTPases are conserved from yeast to humans.
Which protein binds Rab to facilitate vesicle movement toward a target membrane?
Figure 9.33. Vesicle fusion. Vesicle fusion is mediated by binding between specific pairs of v-SNAREs and t-SNAREs on the vesicle and target membranes, respectively. Rab GTP-binding proteins are required to facilitate formation of v-SNARE/t-SNARE complexes.
Which Rab proteins do the vesicles in the Golgi apparatus recruit?
2. Localization of Rab proteins
| Protein | Localization | Function |
|---|---|---|
| late endosome to lysosome transport | ||
| Rab8 | post-Golgi basolateral vesicles, tight junction in polarized cells | Golgi to basolateral plasma membrane |
| transport in polarized cells | ||
| Rab9 | late endosomes, TGN | late endosome to TGN transport |
Are Rab proteins the link between Golgi organization and membrane trafficking?
Rab6 is one of the most extensive studied Rab proteins involved in regulating Golgi trafficking, maintaining its integrity, and its steady-state homeostasis.
What is the role of Rab8 GTPase in the pathophysiology of Madin-Darby disease?
The Rab8 GTPase selectively regulates AP-1B-dependent basolateral transport in polarized Madin-Darby canine kidney cells. J Cell Biol. 2003;163:339–350.
Which suppressor of Sec4 modulates the inhibitory effect of RAB15 during endocytosis?
409. Strick D, Francescutti D, Zhao Y, Elferink L. Mammalian suppressor of Sec4 modulates the inhibitory effect of Rab15 during early endocytosis. J Biol Chem. 2002;277:32722–32729.
What are the effects of Phosphonocarboxylate inhibitors of Rab geranylgeranyl transferase?
88. Coxon F, Ebetino F, Mules E, Seabra M, McKenna C, Rogers M. Phosphonocarboxylate inhibitors of Rab geranylgeranyl transferase disrupt the prenylation and membrane localization of Rab proteins in osteoclasts in vitro and in vivo. Bone. 2005;37:349–358.
What is the mechanism of action of this pan-GTPase inhibitor?
The mechanism of action of this pan-GTPase inhibitor was characterized in the context of the Rab7 GTPase as there are no known inhibitors of Rab GTPases.
