Proteotype Co-evolution and Diversity in Mammals

Evolutionary profiling has been largely limited to the nucleotide level. Using consistent proteomic methods, we quantified proteomic and phosphoproteomic layers in fibroblasts from 11 common mammalian species, with transcriptomic variability as reference. The co-variation analysis indicates that transcript and protein expression robustness across mammals remarkably follows functional role, with extracellular matrix-associated expressions being most variable, demonstrating strong transcriptome-proteome co-evolution. Interestingly, the variability control of gene expression is universal at both inter-individual and inter-species scales, but of different extent. RNA metabolism processes particularly show the higher inter-species versus inter-individual variations. Our results further uncover that while ubiquitin-proteasome system is extremely conserved in mammals, the lysosome-mediated protein degradation exhibits a remarkable variation between mammalian lineages. Additionally, the phosphosite profiles reveals phosphorylation co-evolution network independent of protein abundance.