Mapping Beyond the Genome

With the human genome sequenced, researchers are charting other cell components. The transcriptome describes all the transcriptional units, coding and noncoding, in the genome. The proteome comprises all proteins made by a cell, while the localizome identifies where each peptide resides. These maps vary depending on a cell's age, type, and condition. The glycome and the lipidome map two other classes of biomolecules, carbohydrates and lipids, respectively.

While some researchers are constructing the interactome (see p. 18), others are working on a broader range of biomolecular relationships, including gene-gene and gene-protein interactions, signal transduction pathways, protein-metabolite interactions, and metabolic pathways.

Just as comparative genomics helps explain the human genome, studying maps of other organisms offers clues about similar networks in humans. Researchers are comparing interactions among species to find orthologous complexes. Interactomes of Caenorhabditis elegans, fruit fly, yeast, two bacterial species, and some mouse pathways have been constructed. Scientists in ...