Cyclopamine

Cyclopamine blocks activation of the Hedgehog response pathway associated with mutations that either activate the proto-oncogene Smoothened (Smo) or inactivate the tumour suppressor Patched (Ptch) both of which encode multipass transmembrane proteins.  Furthermore, it has been demonstrated that the inhibitory effect of cyclopamine results from its direct binding to the Smo heptahelical protein bundle