The study of protein-protein interactions is key to understanding the network of molecular interactions underlying biological effects, and defining how individual proteins perform their functional role within a cell. A detailed understanding of these interactions often provides insight into aberrant signaling in disease. This collection brings together the wide range of techniques that have been developed to study interactions using in vitro, cell-based and in vivo approaches. Each technique has its own strengths, for example enabling systematic interrogation of the complete ‘interactome’, providing detailed atomic-level information about a single interaction or insight into the subcellular localization of interacting proteins. Some techniques are easily adaptable to high-throughput screening of libraries or pulling out novel interacting partners while others have a more limited capacity. Readouts such as microscopy and mass-spectrometry are employed in protein-protein interaction techniques and some provide quantitative information on the affinity of the interaction.
Examples of methods to be included in this collection are: co-immunoprecipitation and antibody interference; pull-down assays using fusion proteins or modular protein domains; proximity-dependent labeling techniques (e.g. BioID); far western and receptor affinity probes; affinity purification coupled with mass-spectrometry; two-hybrid technologies (yeast and mammalian); fluorescence microscopy (e.g. immunofluorescence, FRET, super-resolution microscopy); protein complementation assays (e.g. BiFC); biophysical approaches (X-ray crystallography, NMR, AUC, SPR) and microarray-based techniques (i.e. tissue and protein arrays).