Junctophilin 2, also known as JPH2, is a protein which in humans is encoded by the JPH2 gene.

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. This gene is a member of the junctophilin gene family. Alternative splicing has been observed at this locus and two variants encoding distinct isoforms are described. [provided by RefSeq, Jul 2008].
Function: Contributes to the stabilization of the junctional membrane complexes, which are common to excitable cells and mediate cross-talk between cell surface and intracellular ion channels. Probably acts by anchoring the plasma membrane and endoplasmic/sarcoplasmic reticulum. Contributes to the construction of skeletal muscle triad junctions, and plays an essential role in heart development (By similarity).