The MPP7 gene encodes an enzyme belonging to the p55 stardust subset of the Membrane-Associated Guanylate Kinase (MAGUK) family. Members of the MAGUK family function as adaptor proteins that help in the assembly of protein complexes at locations of cell-cell contact. They are thus involved in the formation of synapses, adherens junctions and tight junctions. MPP7 specifically functions by forming a complex with DLG1, a polarity protein, facilitating the establishment of epithelial cell polarity and bicellular tight junction assembly.