RAB40B, Member RAS Oncogene Family (RAB40B)

RAB40B is similar to a yeast protein which suggests a role of the gene product in regulating secretory vesicles. It may be a substrate recognition component of a SCF like ECS E3 ubiquitin ligase complex which mediates the ubiquitination and subsequent proteasomal degradation of target proteins. Although Rab40A and C are up-regulated in neuronal ganglions and nodes, up-regulation of Rab40B is confined to brain tissue with an expression profile nearly identical to that of Rab3A. One possibility is that Rab40B may define an as yet uncharacterized Rab-regulated hub modulating a linked step in the Rab3A-dependent synaptic vesicle cycle in the brain. Alternatively, Rab40B could direct a comparably active postsynaptic dynamic pathway cycling neurotransmitter receptors given that expression profiling of tissues can highlight activities that are linked across cell boundaries.