• Transient Self-Association of Beta2-Adrenergic Receptors

      Lan, Tien-Hung; Department of Pharmacology and Toxicology (2014-03)
      G-protein coupled receptors (GPCRs) constitute the largest family of cell surface receptors. Through binding to ligands such as hormones, peptides, neurotransmitters, or photons, GPCRs are activated and regulate a variety of physiological responses. It has been widely accepted that GPCRs can self-associate as dimers or higher-order oligomers even though protomeric GPCR is capable of activating heterotrimeric G proteins and recruiting arrestins. Although GPCR complexes have been suggested to possess distinct functional properties such as receptor trafficking, receptor phosphorylation, biased downstream signaling, and allosteric communication, the stability and the structural mechanisms for the dimerization of class A GPCRs have not been extensively studied. The β2 adrenergic receptor (β2AR) is a prototype of class A GPCRs and is probably the most extensively studied among the currently available high resolution crystal structures of GPCRs. However, lack of clear dimer interface and the controversy of the stability of β2AR dimeric complexes brings to the question that whether β2AR self-associate as a stable dimer.