Global analysis of protein activities using proteome chips

To facilitate studies of the yeast proteome, we cloned 5800 open reading fr ames and overexpressed and purified their corresponding proteins. The prote ins were printed onto slides at high spatial density to form a yeast proteo me microarray and screened for their ability to interact with proteins and phospholipids. We identified many new calmodulin- and phospholipid-interact ing proteins; a common potential binding motif was identified for many of t he calmodulin-binding proteins. Thus, microarrays of an entire eukaryotic p roteome can be prepared and screened for diverse biochemical activities. Th e microarrays can also be used to screen protein-drug interactions and to d etect posttranslational modifications.