Lon Peptidase 1, Mitochondrial (LONP1)

LONP1 encodes a mitochondrial matrix protein in the Lon family of ATP-dependent proteases. A similar E. coli protein regulates gene expression by targeting specific regulatory proteins for degradation. This protein binds a specific sequence in the light and heavy chain promoters of the mitochondrial genome which are involved in regulation of DNA replication and transcription. The deduced 963-amino acid protein is identical at 46% of positions to 1 or more of 3 bacterial Lon sequences, excluding the N-terminal 98 amino acids of PRSS15, which are unique. The homology is higher in the ATP-binding and serine protease regions. Northern blot analysis detected a 3.4-kb transcript in all tissues tested, with highest expression in heart, brain, liver, and skeletal muscle.