LONP1 Antibody - #DF12119

ATP-dependent serine protease that mediates the selective degradation of misfolded, unassembled or oxidatively damaged polypeptides as well as certain short-lived regulatory proteins in the mitochondrial matrix. May also have a chaperone function in the assembly of inner membrane protein complexes. Participates in the regulation of mitochondrial gene expression and in the maintenance of the integrity of the mitochondrial genome. Binds to mitochondrial promoters and RNA in a single-stranded, site-specific, and strand-specific manner. May regulate mitochondrial DNA replication and/or gene expression using site-specific, single-stranded DNA binding to target the degradation of regulatory proteins binding to adjacent sites in mitochondrial promoters. Endogenous substrates include mitochondrial steroidogenic acute regulatory (StAR) protein, helicase Twinkle (TWNK) and the large ribosomal subunit protein bL32m. bL32m is protected from degradation by LONP1 when it is bound to a nucleic acid (RNA), but TWNK is not.

Mitochondrion matrix.

Duodenum, heart, lung and liver, but not thymus.

Homohexamer. Organized in a ring with a central cavity. The ATP-binding and proteolytic domains (AP-domain) form a hexameric chamber, while the N-terminal domain is arranged as a trimer of dimers. DNA and RNA binding is stimulated by substrate and inhibited by ATP binding. Interacts with TWNK and mitochondrial DNA polymerase subunit POLG.

The Lon N-terminal domains are crucial for the overall structure of the protein, maintaining it in a conformation allowing its proper functioning.

The AP-domain (ATP-binding and proteolytic domains) has a closed-ring conformation in the presence of AMP-PNP and its N-terminal entry gate appears closed. Upon ADP binding, it switches to a lock-washer conformation and its N-terminal gate opens.

The proteolytic site is connected to the ATP binding site through the GG loop (Gly-893 and Gly-894) and the loop containing Trp-770. Binding of a protein substrate such as beta-casein appears to trigger movement of both these loops as part of the conformational changes which lead to enhanced ATPase and peptidase activities.

Belongs to the peptidase S16 family.