Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Models for PTCH regulation of SMO. PTCH likely inhibits SMO by either removing an agonist from SMO (green arrows) or transferring an antagonist to SMO (red arrows). It is unclear whether the exchange between PTCH and SMO occurs between the extracellular domains (A) or transmembrane domains (B). The latter case implicates the existence of a sterol carrier protein that cooperates with PTCH (shown with a question mark).
