An artistic representation of the human proteome project
In a summary of the effort, to be published May 29 in the journal Nature, the team also reports the identification of 193 novel proteins that came from regions of the genome not predicted to code for proteins, suggesting that the human genome is more complex than previously thought.
“You can think of the human body as a huge library where each protein is a book,” says Akhilesh Pandey, M.D., Ph.D., a professor at the McKusick-Nathans Institute of Genetic Medicine and of biological chemistry, pathology and oncology at The Johns Hopkins University and the founder and director of the Institute of Bioinformatics. “The difficulty is that we don’t have a comprehensive catalog that gives us the titles of the available books and where to find them. We think we now have a good first draft of that comprehensive catalog.”
While genes determine many of the characteristics of an organism, they do so by providing instructions for making proteins, the building blocks and workhorses of cells, and therefore of tissues and organs. For this reason, many investigators consider a catalog of human proteins — and their location within the body — to be even more instructive and useful than the catalog of genes in the human genome.
“This was the most exciting part of this study, finding further complexities in the genome,” says Pandey. “The fact that 193 of the proteins came from DNA sequences predicted to be noncoding means that we don’t fully understand how cells read DNA, because clearly those sequences do code for proteins.”
Pandey believes that the human proteome is so extensive and complex that researchers’ catalog of it will never be fully complete, but this work provides a solid foundation that others can reliably build upon.
