Cholesterol Modification of Smoothened Is Required for Hedgehog Signaling

  • Mol Cell. 2017 Apr 6;66(1):154-162.e10. doi: 10.1016/j.molcel.2017.02.015.
Xu Xiao  1 ,  Jing-Jie Tang  1 ,  Chao Peng  2 ,  Yan Wang  3 ,  Lin Fu  4 ,  Zhi-Ping Qiu  5 ,  Yue Xiong  4 ,  Lian-Fang Yang  3 ,  Hai-Wei Cui  3 ,  Xiao-Long He  3 ,  Lei Yin  5 ,  Wei Qi  1 ,  Catherine C L Wong  2 ,  Yun Zhao  4 ,  Bo-Liang Li  1 ,  Wen-Wei Qiu  6 ,  Bao-Liang Song  7
Affiliations
  • 1. State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China.
  • 2. State Key Laboratory of Molecular Biology, National Center for Protein Science Shanghai, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, 333 Haike Road, Shanghai 201203, China; Shanghai Science Research Center, Chinese Academy of Sciences, Shanghai 201204, China.
  • 3. Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200241, China.
  • 4. State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China.
  • 5. Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, the Institute for Advanced Studies, Wuhan University, Wuhan 430072, China.
  • 6. Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200241, China. Electronic address: [email protected].
  • 7. Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, the Institute for Advanced Studies, Wuhan University, Wuhan 430072, China. Electronic address: [email protected].
PMID: 28344083 DOI: 10.1016/j.molcel.2017.02.015
Abstract

Hedgehog (Hh) has been known as the only cholesterol-modified morphogen playing pivotal roles in development and tumorigenesis. A major unsolved question is how Hh signaling regulates the activity of Smoothened (Smo). Here, we performed an unbiased biochemical screen and identified that Smo was covalently modified by Cholesterol on the Asp95 (D95) residue through an ester bond. This modification was inhibited by Patched-1 (Ptch1) but enhanced by Hh. The Smo(D95N) mutation, which could not be Cholesterol modified, was refractory to Hh-stimulated ciliary localization and failed to activate downstream signaling. Furthermore, homozygous SmoD99N/D99N (the equivalent residue in mouse) knockin mice were embryonic lethal with severe cardiac defects, phenocopying the Smo-/- mice. Together, the results of our study suggest that Hh signaling transduces to Smo through modulating its cholesterylation and provides a therapeutic opportunity to treat Hh-pathway-related cancers by targeting Smo cholesterylation.

Keywords
Hedgehog; Patched-1; Smoothened; cholesterol; cholesterylation; ciliary localization; click chemistry; cysteine-rich domain; embryonic lethal; primary cilia.