Functional consequences of 7TM receptor dimerization.

7TM receptors work as signaling platforms that activate multiple signalling systems at the intracellular face of the plasma membrane. It is an emerging concept that 7TM receptors form homo- and hetero-dimers or -oligomers in vitro and in vivo. Numerous studies suggest dimerization is important for receptor function including agonist/antagonist affinity, efficacy, trafficking, and specificity of signal transduction, yet it remains unknown whether dimerization is a prerequisite for 7TM receptor signaling. The current review provides an overview of the biochemical support for 7TM homodimerization, followed by a discussion of the characteristics of homodimerization, with focus on dimer organization, and the functional consequences of dimerization. Heterodimerization will not generally be discussed in this review although we have included a few examples to illustrate specific points, and a table that summarises the current literature on this subject.