Changes in specific protein degradation rates in Arabidopsis thaliana reveal multiple roles of Lon1 in mitochondrial protein homeostasis

• DOI: 10.1111/tpj.13392
• Publication Date: 2016-10-13T15:54:57Z
• Authors: Lei Li; Clark Nelson; Ricarda Fenske; Josua Trösch; Adriana Pružinská; A. Harvey Millar; Shaobai Huang
• Keywords: Protein Degradation; Prohibitin; Ribosomal protein; Proteome

Summary Mitochondrial Lon1 loss impairs oxidative phosphorylation complexes and TCA enzymes causes accumulation of specific mitochondrial proteins. Analysis over 400 protein degradation rates using 15 N labelling showed that 205 were significantly different between wild type ( WT ) lon1‐1 . Those proteins included ribosomal proteins, electron transport chain subunits enzymes. For respiratory I V, decreased abundance correlated with higher rate in total extracts. After blue native separation, however, the assembled had slow degradation, while smaller subcomplexes displayed rapid In insoluble fractions, a number more abundant but degraded slowly soluble less rapidly. These observations are consistent reported roles as chaperone aiding proper folding newly synthesized/imported to stabilise them protease degrade aggregates. HSP 70, prohibitin photorespiration accumulated all indicating an important role their clearance from proteome.