Coordinated activation of cell surface receptors: physiological repercussions

Abstract

For a long time, G-protein-coupled receptors (GPCRs) were considered monomeric and only occasionally interacted with other receptors, mainly members of their own family. This concept has recently changed, and there is ever-growing evidence that this is not the case, thus diversifying their function and ability to respond to the environment. The process by which a membrane receptor triggers signaling pathways from a second one in the absence of protein synthesis is referred to as “transactivation”. This brief review will focus on the intracellular mechanisms and physio-pathological implications of the transactivation process, emphasizing its participation in the regulation of protease-activated receptors (PARs). These were among the first GPCRs for which receptor-receptor interaction was described, thus amplifying their function in a wide variety of tissues and contexts. This new level of molecular interrelation among receptors represents a great opportunity for the development of new therapeutic protocols.