Decreased MRPS34 levels cause a reduction in mitochondrial protein synthesis and steady state levels of mitochondrial proteins.

<p>(A) Protein synthesis in heart and liver mitochondria isolated from <i>Mrps34</i>^<i>wt/wt</i> and <i>Mrps34</i>^{<i>mut/mut</i>} was measured by pulse incorporation of ³⁵S-labelled methionine and cysteine over time. Equal amounts of mitochondrial lysates (50 μg) were separated by SDS–PAGE, Coomassie stained (bottom panel) and visualized by autoradiography (top panel). Mitochondrial lysates (20 μg) from <i>Mrps34</i>^<i>wt/wt</i> and <i>Mrps34</i>^{<i>mut/mut</i>} livers and hearts of young (B) and aged (C) mice were resolved by SDS-PAGE and immunoblotted using antibodies to assess changes in mitochondrial protein abundance. Porin was used as a loading control. Data are means ± SEM of four separate experiments; *, <i>p</i> < 0.05 compared with control treatments by a 2-tailed paired Student’s <i>t</i> test.