Journal: bioRxiv

Article Title: Regulatory principles of human mitochondrial gene expression revealed by kinetic analysis of the RNA life cycle

doi: 10.1101/2023.02.09.527880

Figure Lengend Snippet: Ribosome association fine-tunes mitochondrial protein synthesis but has little predictive power relative to RNA turnover and translation efficiency. A) Distribution of ribosome-association half-lives for mitochondrial-encoded mRNA or nuclear-encoded OXPHOS subunits, measured either from nuclear export (shorter half-lives) or from synthesis (longer). Mito data is from this study and HeLa cells while nuclear-encoded data is from and K562 cells. B) Distribution of the fraction of each mRNA that is bound by ribosomes. Mitochondrial mRNAs are on average more frequently associated with the mitoribosome than nuclear-encoded transcripts with the cytosolic ribosomes. C) Plot showing the correlation between either relative mRNA abundance at steady state (black dots) or mRNA abundance in the ribosome (green dots) and the relative protein synthesis as measured by ribosome profiling (ribosome protected fragments, RPF) . In most cases, the green dots are closer to the midline than the black dots showing that ribosome association brings the total mRNA levels closer to relative protein synthesis levels. D) Quantitative gene expression model using the measured kinetic rates from this study. RPF: ribosome profiling, TE: translation efficiency, k transcription : transcription rate, k deg : turnover rate E) Proportion of protein synthesis explained by different steps of gene expression in HeLa cells. RNA turnover and translation efficiency explain the vast majority of protein synthesis as determined by ribosome profiling, while ribosome association and transcription play minor roles. All data in the figure are from HeLa cells.

Article Snippet: Extracted RNA was rRNA-depleted by hybridization with a custom set of biotinylated-DNA probes complementary only to cytosolic rRNA (riboPOOL, siTOOLS).

Techniques: Expressing