Related Experiment Video

Updated: Nov 1, 2025

Quantitative PCR-based Assay to Measure Sonic Hedgehog Signaling in Cellular Model of Ciliogenesis
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Quantitative PCR-based Assay to Measure Sonic Hedgehog Signaling in Cellular Model of Ciliogenesis

Published on: January 31, 2025

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E3 ubiquitin ligase Wwp1 regulates ciliary dynamics of the Hedgehog receptor Smoothened

Bo Lv1, Michael W Stuck1, Paurav B Desai1

  • 1Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA.

The Journal of Cell Biology
|June 23, 2021
PubMed

Insights

Researchers identified key ubiquitin-related genes controlling the Hedgehog pathway in primary cilia. This discovery sheds light on how Ptch1 regulates Smo levels, crucial for vertebrate development.

Area of Science:

  • Cell Biology
  • Developmental Biology
  • Molecular Biology

Background:

  • The Hedgehog (Hedgehog) pathway is essential for vertebrate development and functions within primary cilia.
  • Hedgehog pathway activation involves Ptch1 exiting cilia, allowing Smo accumulation and downstream signaling.
  • Ubiquitination of Smo is critical for regulating its ciliary levels via intraflagellar transport.

Purpose of the Study:

  • To identify genes involved in regulating ciliary Smo levels at the basal state of the Hedgehog pathway.
  • To elucidate the mechanisms controlling the dynamics of Ptch1 and Smo receptors within primary cilia.

Main Methods:

  • A focused genetic screen of ubiquitin-related genes was performed.
  • Identification of genes required for maintaining low ciliary Smo levels.
  • Investigated the interaction between Wwp1, Ptch1, and ciliary Smo levels.

Main Results:

  • Nine ubiquitin-related genes were identified as necessary for maintaining low ciliary Smo.
  • These include cytoplasmic E3 ligases (Arih2, Mgrn1, Maea), ciliary E3 ligase (Wwp1), ciliary E2 enzyme (Ube2l3), deubiquitinase (Bap1), and adaptors (Kctd5, Skp1a, Skp2).
  • The ciliary E3 ligase Wwp1 binds Ptch1 and is localized to cilia in the basal state; its removal upon signaling activation regulates ciliary Smo levels.

Conclusions:

  • Ptch1 directly or indirectly regulates ciliary Smo levels through the action of Wwp1.
  • This study reveals a novel mechanism involving ubiquitination and ciliary protein dynamics in Hedgehog pathway regulation.
  • Understanding these mechanisms is vital for comprehending vertebrate development and potential therapeutic targets.

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