Understanding Information Processes at the Proteomics Level

Abstract

All living organisms are composed of proteins. Proteins are large, complex molecules made of long chains of amino acids. Twenty different amino acids are usually found in proteins. Proteins are produced on protein-synthesizing machinery directed by codons made of three deoxyribonucleic acid (DNA) bases. DNA is an information storage macromolecule. With the fast advancement of DNA sequencing technology, more and more genomes have been sequenced. Sequence analysis of this exploding genomic information has revealed a lot of novel genes for which molecular and/or biological functions are to be determined. The huge genomic information stored in DNA and genes is stationary and heritable. At cellular level, genomic information flows selectively from DNA to messenger RNA (mRNA) through transcription and from mRNA to proteins through translation for biological functions, such as response to changes in the environment. Different large-scale, high-throughput studies have been performed to investigate the information flow, e.g., transcriptomic profiling using microarray or RNAseq technologies. As a complementary approach to genomics and transcriptomics, proteomics has been fast developing to investigate gene expression at protein levels including quantitative changes, posttranslational modifications, and interactions with other molecules. These protein-level events represent a global view of information processing at the proteomics level. In this chapter, we focus on the description of technological and biological aspects of the information flow from the static ge nome to the dynamic proteome through gene transcription, protein translation, posttranslational modification, and protein interactions.