Figure 6.

Mass spectrometric analysis confirms loss of mitoribosome subunits and mitochondrial translation in the absence of PTCD1. A, Volcano plot showing quantitative comparison of WT and PTCD1 KO#1 cell proteomes. A total of 5075 unique proteins were identified in the cell lysates and the abundance of 304 was significantly different in the KO compared with WT cells. B, PANTHER overrepresentation analysis of proteins depleted or enriched in KO cell lysates. C–E, MS analysis of mitochondria isolated from WT and PTCD1 KO#1 cells. Volcano plots highlight changes in the abundance of selected proteins (each represented by colored dots) between WT and KO cells. C, Comparison of key proteins involved in mitochondrial transcription, replication, and genome maintenance. D, Abundance of mitochondrial ribosomal proteins of the small 28S and large 39S mitoribosome subunit and of accessory and translational factors. E, Abundance of ETC core subunits in WT and KO cells. Data collected from three independent biological experiments. Significance criteria: log2 FC > 1.5 (A, B), log2 FC > 2.0 (C–E); p < 0.05. PANTHER analysis with Fisher's exact and FDR multiple-test correction. See Figure 6-1; Figure 6-2; and Figure 6-3 respectively.