May act as an auxiliary subunit of the unc-2 voltage-gated calcium channel which appears to trigger calcium-activated signaling pathways that control the serotonin response. Inhibiting serotonin sensitivity of the vulval muscles results in egg laying defects. May act in both neurons and muscle cells to enhance motor activity as it is required for coordinated movement. Has a role in neural depolarization-induced calcium influx and pharyngeal pumping (PubMed:8462849, PubMed:8807295, PubMed:16838374). Involved in restricting the expression of the putative olfactory receptor str-2 to only one of the two AWC neurons (PubMed:10571181). Decendants of the cells AB and AB.p (that give rise to nearly all non-pharyngeal neurons), decendants of P1 (that give rise to body muscle) and cell lineages that give rise to the adult and juvenile motor neurons. Expressed in body wall, vulval muscle and pharyngeal muscle. Worms exhibit a weak egg-laying constitutive (Egl-c) phenotype and slow irregular pharyngeal pumping.