Exhibits calcium-dependent phospholipid binding properties (By similarity). May function in membrane trafficking. Regulates synaptic levels of nicotinic acetylcholine receptor subunit lev-1 and unc-38 in the nerve cord (PubMed:15990870). Involved in nicotinic acetylcholine receptor (nAChR)-mediated sensitivity to nicotine and levamisole (PubMed:15990870). Affects directional sperm motility (PubMed:16998478). Interacts with nicotinic acetylcholine receptor. Expressed in head and tail neurons, ventral cord moto-neurons, body wall muscles and hypodermal cells of the vulva. C2 domains are necessary for calcium-dependent cell membrane association. C2 domains are necessary for neuronal progenitor cell differentiation in a calcium-independent manner. Sperm directional motility defects (PubMed:16998478). RNAi-mediated knockdown causes a moderate resistance to nicotine-induced paralysis and a decrease in unc-38 synaptic expression along nerve cords without affecting lev-1 cellular expression levels in muscles (PubMed:15990870). Belongs to the copine family.