Figure 1.

The Protein Homeostasis System that Responds to Protein Aggregation Is Weaker in Brain Tissues Compared with Other Tissues in the Human Body

(A) Comparison between the average expression of genes corresponding to the metastable subproteome (MS) and the average expression of the genes corresponding to the associated protein homeostasis components (PHC) in 77 different types of human tissue (Table S1). The protection factor s defines the strength of the protein homeostasis response to the presence of metastable proteins. Brain tissues have smaller values of s (orange, s = 0.88) than other tissues of the body (blue, s = 1.13), indicating that brain tissues have a reduced ability to protect themselves from protein aggregation relative to other tissues.

(B) Correlation matrix of gene expression levels in different tissues, where the correlation is calculated for the genes corresponding to the MS and their associated PHC. The intensity of the colors and the size of the circles are proportional to the correlation coefficients. Brain tissues (first row) are only weakly correlated with other body tissues, as also illustrated by the body image on the bottom left. The statistical significance was evaluated as explained in Methods and in Figure S1.