Fig. 3: Profiling of MQC protein abundance in disease and control cases.

a Heatmap demonstration of the average levels of signalling protein abundance for individual cases in groups, ranked in diseases (Supplementary Table 1) and protein groups (Fig. 1b). The mean log-transformed intensity data for each tested protein were normalised across tested individuals (scaled by column). b–l Using the linear mixed regression modelling (LMM)²⁶, difference in the abundance signalling proteins between PD neurons and neurons from mitochondrial disease and healthy controls were analysed. The slopes and p values for each tested target from the LMM analysis were summarised into a volcano plot for an integral visualisation (b), with the detailed comparison of proteins that showed a significant change, along with the mitochondrial mass marker (Porin/VDAC1) demonstrated (LMM; p, *≤0.05; ns > 0.05) (c–l). Mitochondrial cases with mtDNA point mutation and POLG mutations as disease controls, alongside healthy aged controls were compared to PD group. Each data point represents each paired group (b) or single neuron (c–l); Boxplots show median and mean (triangle) 25th and 75th percentile, with whiskers indicating 95^th upper/lower interquartile range.