Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Sci. STKE, 27 August 2002
Vol. 2002, Issue 147, p. tw313
[DOI: 10.1126/stke.2002.147.tw313]


Receptor Activation Alternate Path to Smo

The soluble factor Hedgehog (Hh) regulates cell growth and embryonic patterning by activating a cell-surface receptor called Smoothened (Smo). It is thought that Smo is kept inactivated through its association with another transmembrane protein called Patched (Ptc) and that binding of Hh to Ptc relieves Smo inhibition. However, Taipale et al. propose that regulation of this stoichiometric Ptc-Smo relationship may not necessarily underlie Smo activation. The authors show that substoichiometric expression levels of Ptc can regulate Smo. They also found that Smo and Ptc did not colocalize in mammalian cells. It remains unclear how Ptc catalyzes Smo suppression, but the authors detected some similarity between Ptc and a bacterial transmembrane transporter. They suggest that in the absence of Hh, Ptc could translocate a small molecule that either directly or indirectly inhibits Smo.

J. Taipale, M. K. Cooper, T. Maiti, P. A. Beachy, Patched acts catalytically to suppress the activity of Smoothened. Nature 418, 892-897 (2002). [Online Journal]

Citation: Alternate Path to Smo. Sci. STKE 2002, tw313 (2002).

To Advertise     Find Products

Science Signaling. ISSN 1937-9145 (online), 1945-0877 (print). Pre-2008: Science's STKE. ISSN 1525-8882