This gene encodes a member of the polycystin protein family. The encoded protein contains multiple transmembrane domains, and cytoplasmic N- and C-termini. The protein may be an integral membrane protein involved in cell-cell/matrix interactions. The encoded protein may function in renal tubular development, morphology, and function, and may modulate intracellular calcium homoeostasis and other signal transduction pathways. This protein interacts with polycystin 1 to produce cation-permeable currents. Mutations in this gene have been associated with autosomal dominant polycystic kidney disease.