Protein: Junctophilin-2 (JP-2) (Junctophilin type 2) [Cleaved into: Junctophilin-2 N-terminal fragment (JP2NT)] (Q9ET78)
Organism: Mus musculus (Mouse)
Function: Membrane-binding protein that provides a structural bridge between the plasma membrane and the sarcoplasmic reticulum and is required for normal excitation-contraction coupling in cardiomyocytes. Provides a structural foundation for functional cross-talk between the cell surface and intracellular Ca(2+) release channels by maintaining the 12-15 nm gap between the sarcolemma and the sarcoplasmic reticulum membranes in the cardiac dyads. Necessary for proper intracellular Ca(2+) signaling in cardiac myocytes via its involvement in ryanodine receptor-mediated calcium ion release. Contributes to the construction of skeletal muscle triad junctions.
Subcellular location: [Junctophilin-2]: Cell membrane {ECO:0000269|PubMed:10949023}; Peripheral membrane protein {ECO:0000269|PubMed:10949023}. Sarcoplasmic reticulum membrane {ECO:0000269|PubMed:10949023}; Single-pass type IV membrane protein {ECO:0000269|PubMed:10949023}. Endoplasmic reticulum membrane {ECO:0000269|PubMed:10949023}; Single-pass type IV membrane protein {ECO:0000269|PubMed:10949023}. Note=The transmembrane domain is anchored in sarcoplasmic reticulum membrane, while the N-terminal part associates with the plasma membrane (PubMed:10949023). In heart cells, it predominantly associates along Z lines within myocytes (PubMed:10949023). In skeletal muscle, it is specifically localized at the junction of A and I bands (PubMed:10949023). {ECO:0000269|PubMed:10949023}.; SUBCELLULAR LOCATION: [Junctophilin-2 N-terminal fragment]: Nucleus {ECO:0000269|PubMed:30409805}. Note=Accumulates in the nucleus of stressed hearts. {ECO:0000269|PubMed:30409805}.
Sequence: MSGGRFDFDDGGAYCGGWEGGKAHGHGLCTGPKGQGEYSGSWNFGFEVAGVYTWPSGNTFEGYWSQGKRHGLGIETKGRWLYKGEWTHGFKGRYGIRQSTNSGAKYEGTWNNGLQDGYGTETYADGGTYQGQFTNGMRHGYGVRQSVPYGMAVVVRSPLRTSLSSLRSEHSNGTVAPDSPAADGPMLPSPPVPRGGFALTLLATAEAARPQGLFTRGTLLGRLRRSESRTSLGSQRSRLSFLKSELSSGASDAASTGSLAEGAEGPDDAAAPFDADIDATTTETYMGEWKNDKRSGFGVSERSSGLRYEGEWLDNLRHGYGRTTLPDGHREEGKYRHNVLVKGTKRRVLPLKSSKVRQKVEHGVEGAQRAAAIARQKAEIAASRTSHAKAKAEAAEQAALAANQESNIARTLAKELAPDFYQPGPEYQKRRLLQEILENSESLLEPPERGLGTGLPERPRESPQLHERETPQPEGGPPSPAGTPPQPKRPRPGASKDGLLSPGSWNGEPGGEGSRPATPSDGAGRRSPARPASEHMAIEALQPPPAPSQEPEVAMYRGYHSYAVRTGPPEPPPLEDEQEPEPEPEPEVRRSDSAPPSPVSATVPEEEPPAPRSPVPAKQATLEPKPIVPKAEPKAKARKTEARGLSKAGAKKKGRKEVAQAKEAEVEVEEVPNTVLICMVILLNIGLAILFVHLLT
InterPro domains: - IPR017191: Junctophilin (family) [1-696]
- IPR003409: MORN repeat (repeat) [12-330]
Interaction partners: - Triadin
- Ryanodine receptor 1
- Voltage-dependent L-type calcium channel subunit alpha-1S
- Calsequestrin-2
- Ryanodine receptor 3
- Caveolin-3
- Voltage-dependent L-type calcium channel subunit alpha-1C
- Ryanodine receptor 2
- Synaptophysin-like protein 2
- Myc box-dependent-interacting protein 1
Gene Ontology annotations:
Molecular Function (MF): GO:0003674 (molecular function), GO:0005198 (structural molecule activity), GO:0008307 (structural constituent of muscle)
Biological Process (BP): GO:0008150 (biological process), GO:0032502 (developmental process), GO:0032501 (multicellular organismal process), GO:0048856 (anatomical structure development), GO:0007275 (multicellular organism development), GO:0009790 (embryo development), GO:0009792 (embryo development ending in birth or egg hatching), GO:0043009 (chordate embryonic development), GO:0001701 (in utero embryonic development)
Cellular Component (CC): GO:0005575 (cellular component), GO:0032991 (protein-containing complex), GO:0110165 (cellular anatomical entity), GO:0005622 (intracellular anatomical structure), GO:0043226 (organelle), GO:0016020 (membrane), GO:0030018 (Z disc), GO:0071944 (cell periphery), GO:0031984 (organelle subcompartment), GO:0099080 (supramolecular complex), GO:0030017 (sarcomere), GO:0031674 (I band), GO:0005737 (cytoplasm), GO:0012505 (endomembrane system), GO:0031090 (organelle membrane), GO:0043292 (contractile fiber), GO:0043229 (intracellular organelle), GO:0016528 (sarcoplasm), GO:0043228 (non-membrane-bounded organelle), GO:0098827 (endoplasmic reticulum subcompartment), GO:0042175 (nuclear outer membrane-endoplasmic reticulum membrane network), GO:0005783 (endoplasmic reticulum), GO:0043227 (membrane-bounded organelle), GO:0005886 (plasma membrane), GO:0099081 (supramolecular polymer), GO:0016529 (sarcoplasmic reticulum), GO:0043231 (intracellular membrane-bounded organelle), GO:0098588 (bounding membrane of organelle), GO:0043232 (intracellular non-membrane-bounded organelle), GO:0005789 (endoplasmic reticulum membrane), GO:0099512 (supramolecular fiber), GO:0030016 (myofibril), GO:0033017 (sarcoplasmic reticulum membrane)