Calcium/calmodulin-dependent serine protein kinase（CASK）is a member of membrane associated guanylate kinase (MAGUK) family. CASK has multiple protein-binding domains which can interact with other kinds of proteins. CASK acts as a molecular scaffold organizing multiprotein complexes at special areas of the plasma membrane. Mediating a direct link between extracellular matrix and actin cytoskeleton of plasma, CASK might help some proteins to localize to the functional places and be involved in multiple functions of signal transduction, neurotransmitter release in the synapses, nuclear translocation, and transcriptional control.