A presynaptic homeostatic signaling system composed of the Eph receptor, ephexin, Cdc42, and CaV2.1 calcium channels.

ABSTRACT: The molecular mechanisms underlying the homeostatic modulation of presynaptic neurotransmitter release remain largely unknown. In a screen, we isolated mutations in Drosophila ephexin (Rho-type guanine nucleotide exchange factor) that disrupt the homeostatic enhancement of presynaptic release following impairment of postsynaptic glutamate receptor function at the Drosophila neuromuscular junction. We show that Ephexin is sufficient presynaptically for synaptic homeostasis and localizes in puncta throughout the nerve terminal. However, ephexin mutations do not alter other aspects of neuromuscular development, including morphology or active zone number. We then show that, during synaptic homeostasis, Ephexin functions primarily with Cdc42 in a signaling system that converges upon the presyna

SUBMITTER: Frank CA 

PROVIDER: S-EPMC2699049 | biostudies-literature | 2009 Feb

REPOSITORIES: biostudies-literature