Fig. 5. Mitochondrial nonstop mRNAs are generated independent of mitochondrial protein synthesis.

(A) Workflow to inhibit mitochondrial protein synthesis in cultured wild-type fibroblasts to generate RNA for deep sequencing. PBS, phosphate-buffered saline. (B) Northern blotting of total RNA from the whole transcriptome with strand-specific oligonucleotide probes for the indicated RNA transcripts. (C to E) Deep sequencing of the 3′ end of MT-CO3, CYTB, ND1, ND2, ND3, and ND4 from cultured control human fibroblasts with and without mitochondrial translation. CDS + tRNA, CDS with tRNA sequence at the 3′ end; Trunc. CDS + poly A, truncated CDS that were polyadenylated. Each data point represents an independent sample and library preparations. (F) Distribution of the types of nonstop mRNAs for MT-CO3, CYTB, ND1, ND2, ND3, and ND4. Data represent means ± SD from three independent samples and library preparations.