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Updated: May 26, 2026
10:30
Analysis of Tubular Membrane Networks in Cardiac Myocytes from Atria and Ventricles
Published on: October 15, 2014
From myofibril to membrane; the transitional junction at the intercalated disc
1King's College London, Randall Division for Cell and Molecular Biophysics, London SE1 1UL, UK. pauline.bennett@kcl.ac.uk
Frontiers in Bioscience (Landmark Edition)
|December 29, 2011
Summary
The intercalated disc in cardiomyocytes coordinates cell connections and may facilitate new sarcomere addition. This transitional junction is key for maintaining cardiomyocyte structure and function.
Area of Science:
- Cardiology
- Cell Biology
- Muscle Physiology
Background:
- Cardiomyocytes link via intercalated discs, crucial for structural and signaling functions.
- The intercalated disc plays a role in cardiomyocyte cell growth and sarcomere addition.
- The relationship between the intercalated disc and contractile myofibrils is central to myocyte function.
Purpose of the Study:
- To investigate the role of the transitional junction at the intercalated disc in cardiomyocyte structure and function.
- To explore the potential of the transitional junction as a site for new sarcomere addition.
Main Methods:
- Review of existing evidence on cardiomyocyte structure and intercalated disc function.
- Analysis of protein localization in the transitional junction.
- Examination of the role of titin in maintaining sarcomere structure.
Main Results:
- The transitional junction, lacking a terminal Z-disc, connects myofibrils to the folded intercalated disc membrane.
- Actin filaments extend through the transitional junction to transmit tension.
- Specific Z-disc proteins are present in the transitional region, with titin enabling sarcomere maintenance.
Conclusions:
- The transitional junction is strategically positioned for the formation of new Z-disc/SR/T-tubule complexes.
- The intercalated disc's transitional junction is a potential site for sarcomere addition and cardiomyocyte growth.
- Understanding this region is vital for comprehending cardiomyocyte mechanics and development.
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