Stay up to date on the latest science with Brush Up Summaries.
Proteomics is the large-scale study of proteins present at cellular and systemic levels. By generating comprehensive protein datasets, scientists understand the ebb and flow of protein expression in a tissue, how it differs from cell to cell, and how these differences illustrate the inner workings of an organism.1-3
In an organism, thousands of proteins interact in a cell-type and tissue-specific manner to govern cell fates and functions. Protein-coding genes create tens to thousands of copies of different peptides in a cell. Further, protein expression varies from cell to cell and their levels change over time. Many of these proteins interact with each other, localize to distinct subcellular compartments, and undergo post-translational modifications, including phosphorylation, glycosylation, and ubiquitination. Investigating protein levels, composition, interactions, and structures within the cellular context is at the heart of understanding biological systems in health and disease.
What Does the Field of Proteomics Investigate?
Scientists employ three main approaches in proteomics studies: expression, structural, and functional proteomics.2,4
Expression proteomics determines where and when proteins are expressed and measures their quantities. This qualitative and quantitative approach can compare protein expression across conditions, such as health versus disease states, allowing researchers to identify disease-specific proteins. With this expression data, scientists can also identify new cell type markers, which allows them to label and manipulate their samples more accurately.2
Structural proteomics elucidates the three-dimensional structures of different proteins and their interactions with cell compartments, such as membranes, organelles, and nucleosomes.2
Functional proteomics allows researchers to examine protein functions and networks within a cell. By mapping the interaction of a specific protein with numerous partners, including unknown proteins, researchers predict how these interactions drive specific molecular and cellular pathways.2
What Can Proteomics Reveal that Genomics Cannot?
Using genomics, researchers map exomes and whole genomes and identify genetic markers and gene variants. However, one key limitation of genomics is that the data only suggest indirect measurements of cellular states. Protein expression and regulation accurately reflect physiological states, which are measured with proteomics. Further, genomics data do not reveal protein levels, their dynamics across time, and post-translational modifications. With proteomics, scientists generate a map of the complex protein networks and their molecular interactions to gain direct insights into biological pathways.3,5