Cell Biology

Expanding β-Arrestin’s Remit

Science Signaling  01 Jul 2008:
Vol. 1, Issue 26, pp. ec243
DOI: 10.1126/scisignal.126ec243

The β-arrestin proteins help restore G protein-coupled receptors to an inactive state after stimulation. Recently, positive signaling roles for the arrestins have been revealed, as well as roles in signaling by other types of receptors, including the receptor Smoothened (Smo), which has structural similarity to G protein-coupled receptors but signals in a distinct manner. Kovacs et al. (see the Perspective by Rohatgi and Scott) report that β-arrestins 1 and 2 in cultured cells were detected in a complex with a tagged version of the Smo protein and with Kif 3A, a kinesin motor protein. Depletion of β-arrestin 1 or β-arrestin 2 inhibited localization of Smo to primary cilia, which function as "antenna"-like structures rich in receptor proteins. Smo-dependent transcriptional activation was also inhibited if the arrestins were depleted. This Smo-dependent interaction of β-arrestins with Kif 3A may link Smo to the transport apparatus that brings it to the primary cilium.

J. J. Kovacs, E. J. Whalen, R. Liu, K. Xiao, J. Kim, M. Chen, J. Wang, W. Chen, R. J. Lefkowitz, β-arrestin–mediated localization of Smoothened to the primary cilium. Science 320, 1777-1781 (2008). [Abstract] [Full Text]

R. Rohatgi, M. P. Scott, Arrestin' movement in cilia. Science 320, 1726-1727 (2008). [Summary] [Full Text]