RAB9A, Member RAS Oncogene Family (RAB9A)

RAB proteins are GTPases that regulate vesicular trafficking and reside in specific intracellular compartments. RAB9 has been localized to components of the endocytic/exocytic pathway and has been implicated in recycling of membrane receptors, such as mannose 6-phosphate receptor, from early endosomes to the trans Golgi network.

The RAB9 cDNA encodes a 201-amino acid protein whose sequence is almost 100% identical to that of canine Rab9.TIP47 binds directly to the RAB9 GTPase in its active, GTP-bound conformation. Moreover, RAB9 increases the affinity of TIP47 for its cargo. A functional RAB9 binding site was required for TIP47 stimulation of MPR transport in vivo.