Attenuating a cellular signal is just as critical as inducing it. For example, regulator of G protein signaling (RGS) proteins modulate the signaling output from receptor-coupled heterotrimeric G proteins. Zheng et al. (see the Perspective by von Zastrow and Mostov) have identified what has been an elusive RGS for the Gαs class of G proteins. Named RGS-PX1, it also contains a membrane-interacting PhoX domain whose presence suggests a link between G protein signaling and vesicle trafficking in cells.
B. Zheng, Y.-C. Ma, R. S. Ostrom, C. Lavoie, G. N. Gill, P. A. Insel, X.-Y. Huang, M. G. Farquhar, RGS-PX1, a GAP for Gαs and sorting nexin in vesicular trafficking. Science 294, 1939-1942 (2001). [Abstract] [Full Text]
M. von Zastrow, K. Mostov, A new thread in an intricate web. Science 294, 1845-1847 (2001). [Full Text]