The Role of Lysosomes and Microtubules in Cardiac Protein Degradation

  • K. Wildenthal
  • J. S. Crie
  • J. M. Ord
  • J. R. Wakeland
Part of the Advances in Myocardiology book series (ADMY)


The mechanisms and regulatory factors involved in cardiac proteolysis are incom- pletely understo0d. Agents that interfere with lysosomal function (e.g., chloroquine, leupeptin, methyladenine) cause a 25–30% reduction in the overall rate of protein degradation. In the same hearts, however, the rate of myosin breakdown remains unchanged. Disaggregation of microtubules with colchicine is accompanied by a 15% reduction in the rate of degradation of total protein and of myosin. In the same hearts, the degradation of “organellar” protein, including mitochondrial cytochromes, is reduced by over 30%. Thus, it appears that the degradation of different classes of cardiac proteins may be accomplished and regulated by different processes. Lysosomes are important in overall proteolysis, but appear not to be involved in the regulation of myosin breakdown. Microtubules are also involved in the proteolytic process, and appear to be especially important for the breakdown of proteins from mitochondria and perhaps other organelles.


Protein Degradation Autophagic Vacuole Myofibrillar Protein Cardiac Protein Lysosomotropic Agent 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer Science+Business Media New York 1985

Authors and Affiliations

  • K. Wildenthal
    • 1
  • J. S. Crie
    • 1
  • J. M. Ord
    • 1
  • J. R. Wakeland
    • 1
  1. 1.Pauline and Adolph Weinberger Laboratory for Cardiopulmonary Research, Departments of Physiology and Internal MedicineThe University of Texas Health Science Center at DallasDallasUSA

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