JPH1
Domain
The MORN (membrane occupation and recognition nexus) repeats contribute to the plasma membrane binding, possibly by interacting with phospholipids.
Function
Junctophilins contribute to the formation of junctional membrane complexes (JMCs) which link the plasma membrane with the endoplasmic or sarcoplasmic reticulum in excitable cells. Provides a structural foundation for functional cross-talk between the cell surface and intracellular calcium release channels. JPH1 contributes to the construction of the skeletal muscle triad by linking the t-tubule (transverse-tubule) and SR (sarcoplasmic reticulum) membranes.
Sequence Similarities
Belongs to the junctophilin family.
Tissue Specificity
Abundantly expressed in skeletal muscle. Very low levels in heart.
Cellular localization
- Cell membrane
- Peripheral membrane protein
- Endoplasmic reticulum membrane
- Single-pass type IV membrane protein
- Sarcoplasmic reticulum membrane
- Single-pass type IV membrane protein
- Localized predominantly on the plasma membrane. The transmembrane domain is anchored in endoplasmic/sarcoplasmic reticulum membrane, while the N-terminal part associates with the plasma membrane. In skeletal muscle cells, it is predominantly localized at the junction of the A and I bands (By similarity).
Alternative names
JP1, JPH1, Junctophilin-1, JP-1, Junctophilin type 1