Molecular basis of junctional current rectification at an electrical synapse.

ABSTRACT: Rectifying electrical synapses (RESs) exist across animal species, but their rectification mechanism is largely unknown. We investigated why RESs between AVA premotor interneurons and A-type cholinergic motoneurons (A-MNs) in Caenorhabditis elegans escape circuit conduct junctional currents (I _j) only in the antidromic direction. These RESs consist of UNC-7 innexin in AVA and UNC-9 innexin in A-MNs. UNC-7 has multiple isoforms differing in the length and sequence of the amino terminus. In a heterologous expression system, only one UNC-7 isoform, UNC-7b, can form heterotypic gap junctions (GJs) with UNC-9 that strongly favor I _j in the UNC-9 to UNC-7 direction. Knockout of unc-7b alone almost eliminated the I _j, whereas AVA

SUBMITTER: Shui Y 

PROVIDER: S-EPMC7455501 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature