Editors' ChoiceStructural Biology

Choosing a Path

Sci. Signal.  06 Mar 2012:
Vol. 5, Issue 214, pp. ec74
DOI: 10.1126/scisignal.2003012

The β2-adrenergic receptor (β2AR) is a G protein–coupled receptor that recognizes diverse ligands to trigger signaling in the cell. Besides binding G proteins, activated β2AR can be phosphorylated and bind arrestin, which redirects signaling to other pathways. Some β2AR ligands are “biased” in that they differentially activate G protein or arrestin signaling. Liu et al. (see the Perspective by Sprang and Chief Elk) used fluorine-19 nuclear magnetic resonance (19F-NMR) spectroscopy to examine conformational changes associated with a range of ligands and discovered that biased ligands caused differential shifts in equilibrium between two conformational states—the G protein binding state and the arrestin binding state—and thus provide a basis for rational design of pharmacological ligands.

J. J. Liu, R. Horst, V. Katritch, R. C. Stevens, K. Wüthrich, Biased signaling pathways in β2-adrenergic receptor characterized by 19F-NMR. Science 335, 1106–1110 (2012). [Abstract] [Full Text]

S. R. Sprang, J. Chief Elk, Structural origins of receptor bias. Science 335, 1055–1056 (2012). [Abstract] [Full Text]