Protein interaction network mapping
| | The goal of our research is to map protein-protein interaction networks and to understand how those protein interaction networks are modulated through time (evolution) and in response to cellular perturbations.
| | Why study protein-protein interactions?
| 
Biomolecules do not function in isolation - they form networks that provide the mechanistic basis for much of cellular physiology and function.
Protein-protein interactions may form the basis of macromolecular machines (e.g. the proteasome) or they may provide the infrastructure for transmission of information, as in signaling networks. For example, protein-protein interactions are key regulators of the Wnt signaling pathway that has important roles in processes such as embryonic development and human diseases such as colon cancer.
Understanding which proteins interact with which others (and when, and how..) is key to both understanding the function of the protein networks but also to understanding the function of individual proteins - i.e. if we can associate 'orphan' genes with known networks or complexes, that may tell us something about the function of those poorly understood genes.
| | How can we map protein-protein interactions?
| | There are several techniques for large-scale mapping of protein-protein interactions. The most important (in terms of throughput) are the yeast-2-hybrid and affinity-purification mass-spectrometry (AP-MS).
| 
Our favourite technology, AP-MS, works by using a "bait" protein of interest to identify interacting "prey" proteins. AP-MS combines the sensitivity and specificity of antibody-based protein purification ("affinity purification") with the power of mass-spectrometry to identify the prey proteins.
Our current platform uses AP-MS to identify protein networks and complexes from human cells; bait proteins of interest are FLAG-tagged and expressed in human cells (RKO, HEK293). Corresponding protein complexes are then affinity purified and "shotgun proteomics" used to identify and quantify interacting proteins.
AP-MS has been applied to studying the protein interactome of many organisms - including humans. We recently published a large-scale study of human protein interactions - focused on using bait proteins with known biomedical significance (involvement in disease, or biological process of interest).
|
|
|