PCA sounds like a yeast two-hybrid (Y2H) type of system. How do the systems differ?
On a superficial level they are similar. In both cases, elements of a reporter are fused to genes of interest which are co-transfected into a cell. In both cases, the process being measured is a protein-protein interaction. Now the question is whether you can do drug discovery in a meaningful biological context with Y2H. What everyone needs, from the perspective of drug discovery, is to understand the functions of proteins and drugs within the context of a living human cell. This means being able to study fully functional, full-length proteins that are expressed in the correct subcellular compartment, within a cell of choice, and within a pathway of interest. It means being able to perturb a cellular pathway or process – for example, by treating the cell with hormone, cytokine, growth factor, drug, RNAi, or a lead compound – and then ask whether the treatment affected the behavior of a specific protein of interest. It means being able to do those experiments in real time in order to me
