Proteomics: From protein identification to biological function

The term 'proteome' describes the expressed protein complement of a genome. The largely invariant genome of an individual or organism determines its p otential for gene- and protein expression but does not specify which protei ns are expressed in the various types of cells in an organism or individual or their level or extent of post-translational modification. Furthermore, the proteomes of cells are directly affected by environmental factors, such as stress or drug treatment, or by aging and disease. This review briefly describes a selection of the main technologies applied by proteome sciences and their applications to study complex biological problems.