Identifying protein interactors in gonadotropin action.

Systems biology integrates a variety of diverse approaches to the study of the cellular pathways comprised of protein networks. Following an initial ligand-receptor binding event, transduction of the signal is modified in a variety of ways via downstream protein interactions. Protein interactions can occur between two proteins or, alternatively, an interaction between two proteins can be facilitated by an adapter protein. Protein interactions can affect the spatial and temporal distribution of ligand-receptor complexes in cells, attenuating or prolonging signaling. With regard to gonadotropin receptors, protein interactions have been primarily studied in terms of desensitization and termination of signal transduction, or for their role in trafficking. The purpose of this review is to describe protein interactions that mediate gonadotropin receptor functions and to highlight some emerging interactions, as well as some of the caveats inherent in the attempt to uncover these pathways.