A Quantitative Proteome Map of the Human Body

Determining protein levels in each tissue and how they compare with RNA levels is important for understanding human biology and disease as well as regulatory processes that control protein levels. We quantified the relative protein levels from 12,627 genes across 32 normal human tissue types prepared by the GTEx project. We found 5,499 tissue specific or enriched proteins including known and new ones. Tissue-specificity at the RNA level and at the protein level does not always mirror each other: tissue specific or enriched RNAs may be ubiquitously expressed as proteins, while many ubiquitous transcripts are found to encode tissue enriched proteins. Such discordance in the sites of RNA expression and protein detection revealed potential sites of synthesis and action of protein signalling molecules. Examination of tissue specific proteins provided potential insights into human biology and in several cases, a molecular explanation for the underlying defects in disease. Overall, these data provide a valuable resource, and our results demonstrate that understanding protein levels can provide in-depth knowledge into human metabolism, secretome, and tissue biology and disease.