Enables PDZ domain binding activity; neurexin family protein binding activity; and protein C-terminus binding activity. Involved in several processes, including nervous system development; positive regulation of insulin secretion; and protein localization to plasma membrane. Located in several cellular components, including apical dendrite; basolateral plasma membrane; and podocyte foot. Part of protein-containing complex. Human ortholog(s) of this gene implicated in FG syndrome and syndromic X-linked intellectual disability Najm type. Orthologous to human CASK (calcium/calmodulin dependent serine protein kinase). [provided by Alliance of Genome Resources, Apr 2022]