Proteomics and Genomics

Successful completion of sequencing of the human genome showed considerably smaller number of genes (20,000 to 25,000 protein coding genes) (International Human Genome Sequencing Consortium. Lander ES, 2004) than expected and the number of proteins greatly exceeding the number of genes. This had a big impact on how we envision human and other proteomes and how we will approach proteomic and genomic analyses in the future. Isoforms, products of one gene modified by posttranslational modifications or alternative splicing, is only one part of complexity because function and biological role can also depend on cytoplasmic, subcellular compartments, and/or extracellular localization. Interactions with other proteins and nonproteinacious molecules add yet another layer of complexity.