Enables neurexin family protein binding activity and phospholipid binding activity. Acts upstream of or within exocytosis and negative regulation of insulin secretion. Located in secretory granule. Is extrinsic component of membrane. Is expressed in diencephalon lateral wall ventricular layer; endocrine gland; foregut-midgut junction; and paravertebral ganglion. Orthologous to human SYTL4 (synaptotagmin like 4). [provided by Alliance of Genome Resources, Apr 2022]