Past studies have been performed in model organisms such as yeast and different organelles from mice, but no comprehensive analysis of a single type of human cell has been carried out to date. David K. Han and colleagues report a survey of proteins present in Jurkat T cells, which are derived from human T-cell leukemia and is one of the popular types of cells used to study how proteins work inside cells in general.

The scientists identified over 6,400 proteins in a Jurkat T cell and localized them in various parts of the cell. This information will help to understand how proteins move and interact with one another inside the cell and how they perform various cellular functions. The study is also a proof-of-principle that a large-scale study of approximately half of the expressed proteins in a single human cell type is now possible, although more studies will be needed to investigate less abundant proteins and how proteins interact with one another. -American Society for Biochemistry and Molecular Biology