rab gtpases การใช้

Among the fundamental unanswered questions are the directionality of COPI vesicles and role of Rab GTPases in modulating protein cargo traffic.
Rab GTPases need to be geranylgeranyled on either one or two cysteine residues in their C-terminus to localize to the correct intracellular membrane.
In the dimeric holoenzyme, this subunit binds unprenylated Rab GTPases and then presents them to the catalytic Rab GGTase subunit for the geranylgeranyl transfer reaction.
Rab GTPases cycles between the cytosolic compartment, where it is bound to a protein called GDI ( GDP Dissociation Inhibitor ), and the membrane, where it interacts with a receptor, a nucleotide exchange factor, a GAP ( GTPase Activating Protein ) and probably other factors that link it to the appropriate SNARE . GDI is non-specific with respect to the rab it binds.