Rabx-5 regulates RAB-5 early endosomal compartments and synaptic vesicles in C. elegans.

Sharon B Sann, Matthew M Crane, Hang Lu, Yishi Jin

PloS one 2012

filter terms:

Early endosomal membrane compartments are required for the formation and recycling of synaptic vesicles, but how these compartments are regulated is incompletely understood. We performed a forward genetic screen in C. elegans for mutations that affect RAB-5 labeled early endosomal compartments in GABAergic motoneurons. Here we report the isolation and characterization of one mutation, rabx-5. The rabx-5 mutation leads to decreased intensity of YFP::RAB-5 in the cell soma but increased intensity in the synaptic and intersynaptic regions of the axon. This effect is due to the bias of the cycling state of RAB-5, and results from a change in the organization of the early endosomal compartment as well as the membrane binding state of RAB-5. Synaptic vesicle accumulation is altered in rabx-5 mutants, and synaptic transmission from cholinergic neurons is decreased. Early endosomal membrane compartments show disorganization with ageing and rabx-5 mutant animals age faster. These results suggest that rabx-5 regulation of RAB-5 compartments is important for maintaining proper synaptic function throughout the lifetime.

Citation

Sharon B Sann, Matthew M Crane, Hang Lu, Yishi Jin. Rabx-5 regulates RAB-5 early endosomal compartments and synaptic vesicles in C. elegans. PloS one. 2012;7(6):e37930