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Mitochondrial Protein Synthesis Rates Measured by Proteome Dynamics
Author(s) -
Shekar Kadambari Chandra,
Dabkowski Erinne R,
Ling Li,
Ribeiro Rogerio F,
Willard Belinda,
Stanley William C,
Kasumov Takhar
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.1127.2
Subject(s) - cytochrome c oxidase , proteome , chemistry , biochemistry , protein subunit , mitochondrion , heat shock protein , microbiology and biotechnology , biology , gene
Recent studies by our group have established proteome dynamics of plasma proteins using deuterium (2H) labeled water and advance spectrometric methods. In our current study, we used high resolution LTQ Orbitrap mass spectrometry (MS) to assess cardiac mitochondrial proteome dynamics. For preselected time points (0, 3, 20, 40 & 60 days), rats were given a bolus of 2H2O (20 ìl of 2H2O/g body wt) followed by 5% 2H2O in drinking water, which gave 2.7% enrichment. Cardiac mitochondria were isolated and proteins separated by blue‐native gel electrophoresis. The bands were excised, tryptic digested, peptides analyzed by ion trap MS/MS and 2H incorporation was assessed by the high resolution MS. Nuclear encoded proteins in the electron transport chain were analyzed and had similar half lives (30±2 days for ATP synthase F1 beta, 42±2 for Cytochrome C oxidase subunit 4 and 37±6 for Ubiquinone Cytochrome C reductase Core 2), while the mitochondrial encoded protein Cytochrome C oxidase subunit 2 was 44±3 days, suggesting similar rate of synthesis for nuclear and mtDNA encoded proteins. Further, the Krebs cycle protein isocitrate dehydrogenase had a similar half life of 39±5 days. In contrast, heat shock protein 70 had a more rapid turnover (10±0.3 days). These data show that cardiac mitochondrial proteins have a relatively slow turnover for both nuclear and mitochondrial encoded proteins, but a faster turnover for stress proteins.