title: The C-terminal cytoplasmic tail of hedgehog receptor Patched1 is a platform for E3 ubiquitin ligase complexes.
abstract: The Sonic hedgehog (Shh) signaling pathway plays a crucial role in cell proliferation and differentiation via Patched1 (Ptc1), a 12-pass transmembrane receptor protein. The C-terminal cytoplasmic tail of Ptc1 can be cleaved to release the 7th intracellular domain (ICD7), whose function is still unclear. In this study, we found that the ICD7 fragment of Ptc1 associates with polyubiquitinated species. Using mass spectrometry, we identified a cluster of E3 ubiquitin ligase complex as novel Ptc1 ICD7-binding proteins. In particular, Ptc1 ICD7 interacted with most components of the Cullin-2 (CUL2)-based E3 ligase complex, including TCEB1 (EloC), TCEB2 (EloB), ZYG11B, and CUL2 itself. To address the significance of CUL2-based E3 ligase in Ptc1 function, we examined the effects of CUL2 knockdown on Shh-induced osteoblast differentiation in the mesenchymal stem cell line C3H10T1/2. Indeed, knockdown of CUL2 abolished the Shh-induced stem cell differentiation. These results suggest that CUL2-based E3 ligase complex may play a role in Shh- and Ptc1-dependent signaling pathways.
authors.affiliation: Department of Biological Sciences, Tokyo Metropolitan University, Tokyo, 192-0397, Japan.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Yamaki
authors.affiliation: Department of Biological Sciences, Tokyo Metropolitan University, Tokyo, 192-0397, Japan.|Kyoto Pharmaceutical University, 1 Misasagi-shichono-cho, Yamashina-ku, Kyoto, 607-8412, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kagawa
authors.affiliation: Molecular Profiling Research Center for Drug Discovery, National Institute of Advanced Industrial Science and Technology (AIST), Tokyo, 135-0064, Japan.
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Hatta
authors.affiliation: Molecular Profiling Research Center for Drug Discovery, National Institute of Advanced Industrial Science and Technology (AIST), Tokyo, 135-0064, Japan.
authors.forename: Tohru
authors.initials: T
authors.lastname: Natsume
authors.affiliation: Department of Biological Sciences, Tokyo Metropolitan University, Tokyo, 192-0397, Japan. hkawa@tmu.ac.jp.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kawahara
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D003593:Cytoplasm / Q000378:metabolism*; D057809:HEK293 Cells; D053823:Hedgehog Proteins / Q000378:metabolism / Q000502:physiology; D006801:Humans; D051379:Mice; D008809:Mice, Inbred C3H; D000072081:Patched-1 Receptor / Q000378:metabolism*; D013234:Stem Cells / Q000166:cytology; D025801:Ubiquitin / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism*
chemical_list: D053823:Hedgehog Proteins; C000606236:PTCH1 protein, human; D000072081:Patched-1 Receptor; D025801:Ubiquitin; D044767:Ubiquitin-Protein Ligases
keywords: CUL2; Patched1; Sonic hedgehog; Ubiquitin; ZYG11B