Proteomics of membrane receptors and signaling.

Receptors represent an abundant class of integral membrane proteins that transmit information on various types of signals within the cell. Assemblages of receptors and their interacting proteins (receptor complexes) have emerged as important units of signal transduction for various types of receptors including G protein coupled, ligand-gated ion channel, and receptor tyrosine kinase. This review aims to summarize the major approaches and findings of receptor proteomics. Isolation and characterization of receptor complexes from cells has become common using the methods of immunoaffinity-, ligand-, and tag-based chromatography followed by MS for the analysis of enriched receptor preparations. In addition, tools such as stable isotope labeling have contributed to understanding quantitative properties and PTMs to receptors and their interacting proteins. As data from studies on receptor-protein interactions considerably expands, complementary approaches such as bioinformatics and computational biology will undoubtedly play a significant role in defining cellular and network functions for various types of receptor complexes. Findings from receptor proteomics may also shed light on the mechanism of action for pharmacological drugs and can be of value in understanding molecular pathologies of disease states.