Junctional complexes between the plasma membrane and endoplasmic/sarcoplasmic reticulum are a common feature of all excitable cell types and mediate cross talk between cell surface and intracellular ion channels. The protein encoded by this gene is a component of junctional complexes and is composed of a C-terminal hydrophobic segment spanning the endoplasmic/sarcoplasmic reticulum membrane and a remaining cytoplasmic domain that shows specific affinity for the plasma membrane. CAG/CTG repeat expansion from normally 6-28 repeats to 40-59 repeats in the 3' UTR of this gene have been associated with Huntington disease-like 2 (HDL2). This gene is a member of the junctophilin gene family. Alternatively spliced transcript variants have been described for this gene. [provided by RefSeq, Jul 2016].