The claudin-like protein HPO-30 is required to maintain lachrs at the C. Elegans neuromuscular junction

Abstract

Communications across chemical synapses are primarily mediated by neurotransmitters and their postsynaptic receptors. There are diverse molecular systems to localize and regulate the receptors at the synapse. Here, we identify HPO-30, a member of the claudin superfamily of membrane proteins, as a positive regulator for synaptic localization of levamisole dependent acetylcholine receptors (LAChRs) at the Caenorhabditis elegans neuromuscular junction. The HPO-30 protein localizes at the NMJ and shows genetic and physical association with the LAChR subunits LEV-8, UNC-29 and UNC-38. Using genetic and electrophysiological assays in the hermaphrodite C. elegans we demonstrate that HPO-30 functions through the Neuroligin, NLG-1 at the NMJ to maintain postsynaptic LAChR levels at the synapse. Taken together, this work suggests a novel function for a tight junction protein in maintaining normal receptor levels at the NMJ.