Dynamic changes in sarcoplasmic reticulum structure in ventricular myocytes

Amanda L. Vega, Can Yuan, V. Scott Votaw, Luis Fernando Santana

Research output: Contribution to journalArticle

14 Scopus citations

Abstract

The fidelity of excitation-contraction (EC) coupling in ventricular myocytes is remarkable, with each action potential evoking a [Ca 2+] i transient. The prevalent model is that the consistency in EC coupling in ventricular myocytes is due to the formation of fixed, tight junctions between the sarcoplasmic reticulum (SR) and the sarcolemma where Ca 2+ release is activated. Here, we tested the hypothesis that the SR is a structurally inert organelle in ventricular myocytes. Our data suggest that rather than being static, the SR undergoes frequent dynamic structural changes. SR boutons expressing functional ryanodine receptors moved throughout the cell, approaching or moving away from the sarcolemma of ventricular myocytes. These changes in SR structure occurred in the absence of changes in [Ca 2+] i during EC coupling. Microtubules and the molecular motors dynein and kinesin 1(Kif5b) were important regulators of SR motility. These findings support a model in which the SR is a motile organelle capable of molecular motor protein-driven structural changes.

Original languageEnglish (US)
Article number382586
JournalJournal of Biomedicine and Biotechnology
Volume2011
DOIs
StatePublished - 2011
Externally publishedYes

ASJC Scopus subject areas

  • Biotechnology
  • Molecular Medicine
  • Genetics
  • Molecular Biology
  • Health, Toxicology and Mutagenesis
  • Medicine(all)

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