Recent discoveries have led to the realization that proteins involved in synaptic transmission have counterparts in the normal secretory pathways of animal cells and yeast, and thus that the basic machinery involved in these disparate processes is similar. Synaptic proteins with homologues elsewhere include rab3
a, the syntaxins and the VAMPs/synaptobrevins. I have found an additional similarity between a protein implicated in neurotransmitter release and a yeast SEC gene product, which appears to previously have gone unnoticed. Mutations in the unc-18
gene of the nematode Caenorhabditis elegans result in severe paralysis, and confer partial resistance to an acetylcholinesterase inhibitor.