Junctophilin 1 (JPH1)

Junctophilin-1 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. The JP1 gene encodes a deduced 661-amino acid protein. The human JPs share an overall sequence identity of 39%, and they share characteristic structural features with their rabbit and mouse counterparts. RNA blot hybridization indicated that the tissue-specific expression patterns of the JP genes in human are essentially the same as those in mouse; JP1 was expressed as a 4.5-kb transcript in skeletal muscle and at low levels in heart, JP2 was expressed as a 4.1-kb transcript in heart and skeletal muscle, and JP3 was expressed as a 4.6-kb transcript in brain.