title: Patched1 and Patched2 inhibit Smoothened non-cell autonomously.
abstract: Smoothened (Smo) inhibition by Patched (Ptch) is central to Hedgehog (Hh) signaling. Ptch, a proton driven antiporter, is required for Smo inhibition via an unknown mechanism. Hh ligand binding to Ptch reverses this inhibition and activated Smo initiates the Hh response. To determine whether Ptch inhibits Smo strictly in the same cell or also mediates non-cell-autonomous Smo inhibition, we generated genetically mosaic neuralized embryoid bodies (nEBs) from mouse embryonic stem cells (mESCs). These experiments utilized novel mESC lines in which Ptch1, Ptch2, Smo, Shh and 7dhcr were inactivated via gene editing in multiple combinations, allowing us to measure non-cell autonomous interactions between cells with differing Ptch1/2 status. In several independent assays, the Hh response was repressed by Ptch1/2 in nearby cells. When 7dhcr was targeted, cells displayed elevated non-cell autonomous inhibition. These findings support a model in which Ptch1/2 mediate secretion of a Smo-inhibitory cholesterol precursor.
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States.
authors.forename: Brock
authors.initials: B
authors.lastname: Roberts
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States.
authors.forename: Catalina
authors.initials: C
authors.lastname: Casillas
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States.
authors.forename: Astrid C
authors.initials: AC
authors.lastname: Alfaro
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States.
authors.forename: Carina
authors.initials: C
authors.lastname: Jägers
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States.
authors.forename: Henk
authors.identifier: 0000-0002-5260-3634
authors.initials: H
authors.lastname: Roelink
mesh_terms: D000818:Animals; D055786:Gene Knockout Techniques; D053823:Hedgehog Proteins / Q000378:metabolism; D051379:Mice; D000066450:Mouse Embryonic Stem Cells / Q000502:physiology; D000072081:Patched-1 Receptor / Q000235:genetics / Q000378:metabolism*; D000072082:Patched-2 Receptor / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D000072086:Smoothened Receptor / Q000037:antagonists & inhibitors* / Q000235:genetics
chemical_list: D053823:Hedgehog Proteins; D000072081:Patched-1 Receptor; D000072082:Patched-2 Receptor; C000606240:Ptch1 protein, mouse; C000606241:Ptch2 protein, mouse; C491022:Smo protein, mouse; D000072086:Smoothened Receptor
keywords: RND antiporters; Shh; Smo; developmental biology; mouse; patched; stem cells