Enables calcium channel activity. Involved in positive regulation of filopodium assembly; regulation of synapse organization; and synapse assembly. Located in several cellular components, including filopodium; neuron projection; and neuronal cell body. Is active in glutamatergic synapse. Is integral component of presynaptic active zone membrane. Orthologous to human GPM6A (glycoprotein M6A). [provided by Alliance of Genome Resources, Apr 2022]