G Protein Signaling

From Receptor to Nucleus

Science's STKE  19 Jun 2001:
Vol. 2001, Issue 87, pp. tw3
DOI: 10.1126/stke.2001.87.tw3

The binding of extracellular ligands to their receptors on the cell membrane can evoke a variety of responses, and in some cases, these responses include a change in gene expression and in transcription. Santagata et al. describe a new pathway in which occupancy of a plasma-membrane receptor results in mobilization of a transcription factor to the nucleus. In its inactive state, the protein Tubby, which has been connected to adult-onset obesity in mice, binds to the phosphorylated head group of a plasma-membrane lipid. When the G protein-coupled serotonin receptor is activated, phospholipase C hydrolyzes the lipid and releases Tubby, which then enters the nucleus, probably through its nuclear localization sequence. An intriguing suggestion is that this result may explain why serotonin-receptor knockout mice display symptoms of adult-onset obesity. Cantley writes a Perspective on the paper.

S. Santagata, T. J. Boggon, C. L. Baird, C. A. Gomez, J. Zhao, W. S. Shan, D. G. Myszka, L. Shapiro, G protein signaling through Tubby proteins. Science 292, 2041-2050 (2001). [Abstract] [Full Text]

L. C. Cantley, Translocating Tubby. Science 292, 2019-2021 (2001). [Full Text]