Cell surface protein which plays a role in the plasticity of cholinergic synapses at neuromuscular junctions and in the polarity of the mechanosensory neuron ALM, possibly by antagonizing Wnt signaling. Membrane association is important for synaptic function. Expressed in the cholinergic motor neurons AS, VA and DA in the ventral nerve cord and in the mechanosensory ALM neurons in the midbody. RNAi-mediated knockdown results in hypersensitivity to the acetylcholinesterase inhibitor aldicarb, indicating increased cholinergic transmission in mutant animals.