High impact information on RAB15

• We previously reported that Rab15 differentially regulates transferrin receptor trafficking through sorting endosomes and the endocytic recycling compartment, suggesting a role for distinct Rab15-effector interactions at these endocytic compartments [1].
• Rab15 may interfere with Rab5 function directly by sequestering Rab5 effectors or indirectly through novel sets of effector interactions [2].
• Mammalian suppressor of Sec4 modulates the inhibitory effect of Rab15 during early endocytosis [2].
• Mutational analysis of Rab15 indicates that lysine at position 48 (K48Q) is important for the binding of Rab15-GDP to Mss4 [2].
• Moreover, the mutation K48Q counters the inhibitory phenotype of wild type Rab15 on receptor-mediated endocytosis in HeLa cells and homotypic endosome fusion in vitro without altering the relative amount of cell surface-associated transferrin receptor [2].

Anatomical context of RAB15

• This data suggests that rab15 may act in concert with rab3A in regulating aspects of synaptic vesicle membrane flow within the nerve terminal [3].
• We recently demonstrated that epitope-tagged Rab15 (HArab15) co-localizes with Rab4, -5, and -11 on early endosomal membranes in CHO cells (Zuk, P. A., and Elferink, L. A. (1999) J. Biol. Chem. 274, 22303-22312) [4].

References