Switch from ER-mitochondrial to SR-mitochondrial calcium coupling during muscle differentiation.

ABSTRACT: Emerging evidence indicates that mitochondria are locally coupled to endoplasmic reticulum (ER) Ca2+ release in myoblasts and to sarcoplasmic reticulum (SR) Ca2+ release in differentiated muscle fibers in order to regulate cytoplasmic calcium dynamics and match metabolism with cell activity. However, the mechanism of the developmental transition from ER to SR coupling remains unclear. We have studied mitochondrial sensing of IP3 receptor (IP3R)- and ryanodine receptor (RyR)-mediated Ca2+ signals in H9c2 myoblasts and differentiating myotubes, as well as the attendant changes in mitochondrial morphology. Mitochondria in myoblasts were largely elongated, luminally connected and relatively few in number, whereas the myotubes were densely packed with globular mitochondria that displayed limite

SUBMITTER: Yi M 

PROVIDER: S-EPMC3607359 | biostudies-literature | 2012 Nov

REPOSITORIES: biostudies-literature