Receptor Oligomerization and Trafficking

G protein-coupled receptor (GPCR) dimerization is a mechanism for regulating the signaling from several classes of plasma membrane receptors and has been a particularly well-studied mechanism for the regulation of tyrosine kinase (Trk) receptors (reviewed in ref. 1). As reported for Trk and cytokine receptors, some GPCRs may also dimerize in response to agonist (2–6). However, GPCRs can also form constitutive dimers—often as early as during their biosynthesis (7–9). Adding to this complexity, GPCRs can form not only homodimers but also heterodimers with altered properties. Ultimately, one main goal is to understand the functional consequences of GPCR dimerization.