Fig. 3.

Quantitative analysis of N termini abundance in Clpp^−/− and wt mouse heart mitochondria.A, Abundance in Clpp^−/− and wt for 154 expected N-terminal peptides matching within 5 amino acids distance from UniProt annotated translation start or maturation sites and for 623 N-terminal peptides matching to unexpected positions with the corresponding protein model. Asterisk indicates significant difference between the mean values of the two distributions (Mann-Whitney U test p-val <0.001), emphasized by dashed line. Red, unexpected N termini; blue, expected N termini; gray, subset of 93 unexpected N termini matching to proteins that showed no significant change in abundance in the LFQ data set used to define cut-off values of significant accumulation (light orange) or depletion (light blue) of unexpected N termini. B, Abundance of N-terminal peptides compared with the corresponding protein abundance determined by label-free quantification. Red, unexpected N termini; blue, expected N termini. Pearson correlation for each group is indicated. C, iceLogo of 37 unexpected N termini with reduced abundance in CLPP-deficient mitochondria (log₂(Clpp^−/−/wt)<0.9). D, iceLogo of 49 unexpected N termini accumulating in CLPP-deficient mitochondria (log₂(Clpp^−/−/wt>0.9).