Mapping Human Cells

A new tool developed by researchers at the Lunenfeld-Tanenbaum Research Institute in Toronto, Canada, provides an in-depth view of intracellular proteins and how they are organized within living human cells. This tool could help further our understanding of what happens inside human cells during disease. 

Led by Dr. Anne-Claude Gingras, a professor at the University of Toronto, the study was published June 2 in Nature.

Though researchers have used microscopy and mass spectrometry to study the intracellular proteins present in different organelles inside human cells, certain intracellular compartments have evaded detection. The new tool uses a proximity-dependent biotinylation method called BioID, which labels proteins that interact with a predetermined marker protein. This alternative approach allows researchers to study protein organization within living cells.

Here, researchers used 192 subcellular marker proteins already known to be present inside specific organelles to “tag” nearby proteins within the same compartment. They then isolated the tagged proteins and identified them via mass spectrometry. Computational analysis of the data resulted in a map with the locations of 4,145 unique intracellular proteins inside HEK293 cells, a common human cell line used for research.

Understanding where different proteins are located inside cells and their potential interactions could help researchers better understand the molecular pathogenesis of disease. Future research will examine intracellular protein localization during infection and disease to study how cells adapt under these conditions.

The resulting Human Cell Map can be viewed at humancellmap.org.