What is yeast two-hybrid?

This is a technique used to test for protein-protein interactions. The process starts by getting a genetically modified yeast. This yeast either has a modification that causes it to lack a necessary  component for its growth or to code for some sort of reporter protein. The proteins that we want to test are then introduced through plasmids. The proteins are not normal though. One will be made with an activating domain attached to it and the other will be made with a binding domain. When these two domains are close together you will get a transcription factor. In this specific case, the transcription factor will be a factor that activates the promoter of the edited gene in our yeast. Therefore, if our two protiens really do interact, they will bring make a complete transcription factor and activate the gene placed into the yeast.