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. Involved in restricting the expression of the putative olfactory receptor str-2 to only one of the two AWC neurons.