title: Multitasking in the mitochondrion by the ATP-dependent Lon protease.
abstract: 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.
authors: Department of Biochemistry and Molecular Biology, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, 185 South Orange Avenue, MSB E-633, Newark, New Jersey 07103 USA.
authors: Sundararajan
authors: S
authors: Venkatesh
authors: Jae
authors: J
authors: Lee
authors: Kamalendra
authors: K
authors: Singh
authors: Irene
authors: I
authors: Lee
authors: Carolyn K
authors: CK
authors: Suzuki
mesh_terms: D000818:Animals; D017124:Conserved Sequence; D004272:DNA, Mitochondrial / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D008565:Membrane Proteins; D008928:Mitochondria / Q000201:enzymology*; D008969:Molecular Sequence Data; D049070:Protease La / Q000737:chemistry* / Q000378:metabolism; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D059748:Proteolysis; D029701:Saccharomyces cerevisiae Proteins
chemical_list: C438144:ASI1 protein, S cerevisiae; D004272:DNA, Mitochondrial; D004268:DNA-Binding Proteins; D008565:Membrane Proteins; D029701:Saccharomyces cerevisiae Proteins; D049070:Protease La