Logo image
Ca²⁺ microdomains organized by junctophilins
Journal article   Open access   Peer reviewed

Ca²⁺ microdomains organized by junctophilins

Hiroshi Takeshima, Masahiko Hoshijima and Long-Sheng Song
Cell calcium (Edinburgh), Vol.58(4), pp.349-356
10/2015
DOI: 10.1016/j.ceca.2015.01.007
PMCID: PMC5159448
PMID: 25659516
url
https://doi.org/10.1016/j.ceca.2015.01.007View
Published (Version of record) Open Access

Abstract

•Three-dimensional electron microscopy is providing the new knowledge of junctional membrane complexes (JMCs).•Junctophlins (JPs) are essential to structure JMCs in excitable cells.•Quantitative and qualitative alterations of JPs are associated with a wide range of human diseases. Excitable cells typically possess junctional membrane complexes (JMCs) constructed by the plasma membrane and the endo/sarcoplasmic reticulum (ER/SR) for channel crosstalk. These JMCs are termed triads in skeletal muscle, dyads in cardiac muscle, peripheral couplings in smooth and developing striated muscles, and subsurface cisterns in neurons. Junctophilin subtypes contribute to the formation and maintenance of JMCs by serving as a physical bridge between the plasma membrane and ER/SR membrane in different cell types. In muscle cells, junctophilin deficiency prevents JMC formation and functional crosstalk between cell-surface Ca2+ channels and ER/SR Ca2+ release channels. Human genetic mutations in junctophilin subtypes are linked to congenital hypertrophic cardiomyopathy and neurodegenerative diseases. Furthermore, growing evidence suggests that dysregulation of junctophilins induces pathological alterations in skeletal and cardiac muscle.
Calcium channel Excitation–contraction coupling Muscle

Details

Metrics

Logo image