Exploring the Human Protein Atlas to Study Biology and Disease

The human genome has approximately 20,000 protein-encoded genes. An import quest for the future is to characterize the expression, localization, and modification of all the human proteins. The current version 9.0 of the Human Protein Atlas (www. proteinatlas.org) contains more than 15,000 validated antibodies targeting 12,200 genes corresponding to more than 60% of the protein-encoded genes in humans. The Protein Atlas contains more than 12 million high-resolution images generated by immunohistochemistry and confocal microscopy. The antibodies have been generated to regions of low homology. The long term objective is to generate paired antibodies towards the protein targets with separate and non-overlapping epitopes. Pilot projects have been initiated to also generate recombinant affinity reagents, a pilot version of a Rodent Brain Protein Atlas, and to study human biology. In addition, we have developed a targeted MS-proteomics strategy based on the recombinant protein fragments (PrESTs) generated within the frame-work of the Protein Atlas project. We have used the human protein atlas to study the global protein expression patterns in human cells, tissues and organs, as well as a discovery tool to find potential biomarkers for diseases, such as cancer.