In our paper, we reported crystal structures of sterol-activated Smoothened. It has come to our attention that we failed to cite an important contemporaneous contribution from Rohatgi and colleagues (Luchetti et al., 2016) who reported identification of cholesterol as the endogenous SMO agonist. This reference has been added online to the References and a citation added in the Introduction and the Discussion alongside the Huang et al., 2016 reference that we had already cited. We apologize to Drs Luchetti, Rohatgi, and colleagues and to the community for this breach of scholarship.
In addition, a concerned reader pointed out that we were not clear in describing the mutations in a construct used for crystallization. In Figure S1, we describe the construct xSMO-BRIL-glycKO consisting of Xenopus laevis SMO (xSMO) with its intracellular loop 3 (ICL3) replaced by thermostabilized apocytochrome b562RIL (BRIL) and glycosylation sites removed, to facilitate crystallization. We should have included the information that three glycosylation sites were removed with the following mutations: S163A, N282S, and T468A. As reported previously (Marada et al., 2015) removal of conserved SMO glycosylation sites from mouse SMO has no effect on canonical Hh signaling; however, the thermostabilized apocytochrome itself interferes with downstream signaling. Description of the mutations and citation of Marada et al., 2015 has been added online in the Results and STAR Method DNA constructs sections, and Marada et al., 2015 has been added to the Reference list. We apologize for any confusion and inconvenience this has caused.
Figure S1.
Structural Alignment of SMO Homologs (Corrected)
Figure S1.
Structural Alignment of SMO Homologs (original)
REFERENCES
- Luchetti G, Sircar R, Kong JH, Nachtergaele S, Sagner A, Byrne EF, Covey DF, Siebold C, and Rohatgi R (2016). Cholesterol activates the G-protein coupled receptor Smoothened to promote Hedgehog signaling. eLife 5, e20304. [DOI] [PMC free article] [PubMed] [Google Scholar]
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