Multitasking in the mitochondrion by the ATP-dependent Lon protease

Biochim Biophys Acta. 2012 Jan;1823(1):56-66. doi: 10.1016/j.bbamcr.2011.11.003. Epub 2011 Nov 18.


The AAA(+) Lon protease is a soluble single-ringed homo-oligomer, which represents the most streamlined operational unit mediating ATP-dependent proteolysis. Despite its simplicity, the architecture of Lon proteases exhibits a species-specific diversity. Homology modeling provides insights into the structural features that distinguish bacterial and human Lon proteases as hexameric complexes from yeast Lon, which is uniquely heptameric. The best-understood functions of mitochondrial Lon are linked to maintaining proteostasis under normal metabolic conditions, and preventing proteotoxicity during environmental and cellular stress. An intriguing property of human Lon is its specific binding to G-quadruplex DNA, and its association with the mitochondrial genome in cultured cells. A fraction of Lon preferentially binds to the control region of mitochondrial DNA where transcription and replication are initiated. Here, we present an overview of the diverse functions of mitochondrial Lon, as well as speculative perspectives on its role in protein and mtDNA quality control.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Review

MeSH terms

  • Animals
  • Conserved Sequence
  • DNA, Mitochondrial / metabolism
  • DNA-Binding Proteins / chemistry*
  • DNA-Binding Proteins / metabolism
  • Humans
  • Membrane Proteins
  • Mitochondria / enzymology*
  • Molecular Sequence Data
  • Protease La / chemistry*
  • Protease La / metabolism
  • Protein Structure, Quaternary
  • Protein Structure, Tertiary
  • Proteolysis
  • Saccharomyces cerevisiae Proteins


  • ASI1 protein, S cerevisiae
  • DNA, Mitochondrial
  • DNA-Binding Proteins
  • Membrane Proteins
  • Saccharomyces cerevisiae Proteins
  • Protease La