Home Blog of Signal Transduction GPCR & G Protein Hedgehog/Smoothened Cellular Cholesterol Directly Activates Smoothened in Hedgehog Signaling

Category

Archives

Popular Post

ESKM, a novel therapeutic agent for sensitive and resistant PH+ leukemias

The mechanism of resistance to JAK2 inhibitor in myeloproliferative neoplasms patients

Effects of PARP inhibitors in BRCA gene-mutated ovarian cancer

DASATINIB; An inhibitor of Receptor Tyrosine Kinase

GP130/JAK/STAT3 signaling pathway induces multiple myeloma

Cellular Cholesterol Directly Activates Smoothened in Hedgehog Signaling

In vertebrates, sterols are necessary for Hedgehog signaling, a pathway critical in embryogenesis and cancer. Sterols activate the membrane protein Smoothened by binding its extracellular, cysteine-rich domain (CRD). Major unanswered questions concern the nature of the endogenous, activating sterol and the mechanism by which it regulates Smoothened. We report crystal structures of CRD complexed with sterols and alone, revealing that sterols induce a dramatic conformational change of the binding site, which is sufficient for Smoothenedactivation and is unique among CRD-containing receptors. We demonstrate that Hedgehog signaling requires sterol binding to Smoothenedand define key residues for sterol recognition and activity. We also show that cholesterol itself binds and activates Smoothened. Furthermore, the effect of oxysterols is abolished in Smoothened mutants that retain activation by cholesterol and Hedgehog. We propose that the endogenous Smoothened activator is cholesterol, not oxysterols, and that vertebrate Hedgehog signaling controls Smoothened by regulating its access to cholesterol.

Related Products

Cat.No. Product Name Information
S7779 SAG (Smoothened Agonist) HCl SAG (Smoothened Agonist) HCl is a cell-permeable Smoothened (Smo) agonist with EC50 of 3 nM in Shh-LIGHT2 cells.

Related Targets

Hedgehog/Smoothened