Building a protein interaction map: research in the post-genome era.

With the extensive amount of information generated by genome-wide sequencing, the entire set of gene products in an organism can now be predicted. The challenge of understanding the function of each gene in the genome has led to the development of many large-scale and high-throughput experimental techniques. Recently, two papers, Walhout et al.(1) and Uetz et al.,(2) have described studies that add a new functional dimension to research conducted on a genome-wide scale. These two groups have utilized the yeast two-hybrid system to identify interactions among the entire complement of proteins encoded by the Caenorhabditis elegans and the Saccharomyces cerevisiae genomes, respectively. Using a set of 29 genes that have been previously characterized, Walhout et al. demonstrated the feasibility and efficiency of this technique by building an interaction matrix among a large number of proteins. On an even larger scale, Uetz et al. conducted two-hybrid analyses using proteins that represent over 87% of the total gene products in yeast and identified interactions for about 15% of the total yeast proteins. BioEssays 22:503-506, 2000. Copyright 2000 John Wiley & Sons, Inc.