5. Protein Degradation in Aging Cells and Mitochondria: Relevance to the Neuromuscular System

  1. Valerie Askanas MD, PhD and
  2. W. King Engel MD
  1. Jenny K. Ngo PhD1 and
  2. Kelvin J. A. Davies PhD, DSc2

Published Online: 19 DEC 2011

DOI: 10.1002/9781444398311.ch5

Muscle Aging, Inclusion-Body Myositis and Myopathies

Muscle Aging, Inclusion-Body Myositis and Myopathies

How to Cite

Ngo, J. K. and Davies, K. J. A. (2012) Protein Degradation in Aging Cells and Mitochondria: Relevance to the Neuromuscular System, in Muscle Aging, Inclusion-Body Myositis and Myopathies (eds V. Askanas and W. K. Engel), Wiley-Blackwell, Oxford, UK. doi: 10.1002/9781444398311.ch5

Editor Information

  1. Departments of Neurology and Pathology, University of Southern California Neuromuscular Center, University of Southern California Keck School of Medicine, Good Samaritan Hospital, Los Angeles, CA, USA

Author Information

  1. 1

    Davis School of Gerontology, Ethel Percy Andrus, Gerontology Center, University of Southern California, Los Angeles, CA, USA

  2. 2

    Andrus Gerontology Center, The University of Southern California, Los Angeles, CA, USA

Publication History

  1. Published Online: 19 DEC 2011
  2. Published Print: 27 JAN 2012

ISBN Information

Print ISBN: 9781405196468

Online ISBN: 9781444398311

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Keywords:

  • aging;
  • Lon protease;
  • mitochondria;
  • oxidative stress;
  • proteasome

Summary

A natural part of aerobic metabolism is the generation of free radicals into cells and its organelles. These toxic by-products cause damage to macromolecules, especially postmitotic cells that are long lived and have accumulated oxidative protein damage over a long time. Several lines of antioxidant systems are on hand to counteract oxidative damage to cells before permanent and irreversible protein cross-links form. Major secondary defenses include proteases that repair or remove damaged proteins before aggregation occurs. The cytosol, nucleus, and endoplasmic reticulum rely on the proteasome, while the mitochondria have the Lon protease, both of which selectively degrade oxidized proteins. In this chapter, we discuss the role of the proteasome and Lon, and their relevance in protein quality control. Dysfunction in both these systems contributes to the high level of oxidative protein damage and mitochondrial failure, and lowers the quality of life in patients with aging neuromuscular cells.