Protein Expression Profiling

Abstract

Much work in biochemistry and physiology already has shown us that biochemical pathways are constantly in flux. The use of DNA microarrays has demonstrated that gene-expression patterns in cells are also changing constantly. Indeed, one can use either old or new technologies to observe regular changes in the status of many enzymes during the daily life cycle of an organism or in the cycle of a cell. All this suggests that the proteomes of cells are constantly changing as well. In addition to these changes that are essential to life, other changes are induced by environmental stimuli, chemicals, drugs, and growth and disease processes. Many of these latter changes interest those trying to understand complicated pathologies (e.g., cancer) or trying to identify novel targets for therapeutic drugs. Perhaps the ultimate challenge of proteomics is to measure the status of all cellular proteins as they change with time. Unfortunately, the technology is not yet there. Nevertheless, the problem of comparing proteomes between two states of a cell or organism is relevant and important.