Global Proteome of LonP1 +/- Mouse Embryonal Fibroblasts Reveals Impact on Respiratory Chain, but No Interdependence between Eral1 and Mitoribosomes

• Published in: International journal of molecular sciences Vol. 20; no. 18; p. 4523
• Main Authors: Key, Jana, Kohli, Aneesha, Bárcena, Clea, López-Otín, Carlos, Heidler, Juliana, Wittig, Ilka, Auburger, Georg
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 12-09-2019; MDPI
• Subjects: Adenosine triphosphatase; Animals; Apoptosis; Ataxia; ATP-Dependent Proteases - metabolism; Autophagy; Biosynthesis; Cells, Cultured; CODAS syndrome; Cytochrome-c oxidase; Disease; Electron Transport; Embryo, Mammalian - cytology; Embryo, Mammalian - metabolism; Fibroblasts; Fibroblasts - metabolism; fidelity protein synthesis; glutathione pathway; Growth rate; GTP-Binding Proteins - metabolism; Hearing loss; Heme; Homology; Immune system; Infertility; life expectancy; Lon protein; longevity; lysosomal degradation; Mice; Mitochondria; Mitochondrial DNA; Mitochondrial Proteins - metabolism; Mitochondrial Ribosomes - metabolism; Mutation; Oxidative stress; Perrault syndrome; Phosphorylation; Protease; protease target substrates; Protein Interaction Maps; Proteins; Proteolysis; Proteome - metabolism; Proteomes; respiratory complex assembly; RNA-Binding Proteins - metabolism; Serine; Serine peptidase; Steroidogenic acute regulatory protein; life expectancy; lysosomal degradation; Perrault syndrome; glutathione pathway; CODAS syndrome; longevity; respiratory complex assembly; protease target substrates; fidelity protein synthesis; oxidative stress
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms20184523

Research on healthy aging shows that lifespan reductions are often caused by mitochondrial dysfunction. Thus, it is very interesting that the deletion of mitochondrial matrix peptidase LonP1 was observed to abolish embryogenesis, while deletion of the mitochondrial matrix peptidase Caseinolytic Mitochondrial Matrix Peptidase Proteolytic Subunit (ClpP) prolonged survival. To unveil the targets of each enzyme, we documented the global proteome of
mouse embryonal fibroblasts (MEF), for comparison with
depletion. Proteomic profiles of
MEF generated by label-free mass spectrometry were further processed with the STRING (Search tool for the retrieval of interacting genes) webserver Heidelberg for protein interactions. ClpP was previously reported to degrade Eral1 as a chaperone involved in mitoribosome assembly, so ClpP deficiency triggers the accumulation of mitoribosomal subunits and inefficient translation.
MEF also showed Eral1 accumulation, but no systematic effect on mitoribosomal subunits. In contrast to
profiles, several components of the respiratory complex-I membrane arm, of the glutathione pathway and of lysosomes were accumulated, whereas the upregulation of numerous innate immune defense components was similar. Overall, LonP1, as opposed to ClpP, appears to have no effect on translational machinery, instead it shows enhanced respiratory dysfunction; this agrees with reports on the human CODAS syndrome (syndrome with cerebral, ocular, dental, auricular, and skeletal anomalies) caused by LonP1 mutations.