Open AccessE3 ubiquitin ligase Wwp1 regulates ciliary dynamics of the Hedgehog receptor Smoothened
Author(s) -
Bo Lv,
Michael W. Stuck,
Paurav B. Desai,
Oscar A. Cabrera,
Gregory J. Pazour
Publication year - 2021
Publication title -
the journal of cell biology/the journal of cell biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.414
H-Index - 380
eISSN - 1540-8140
pISSN - 0021-9525
DOI - 10.1083/jcb.202010177
Subject(s) - smoothened , biology , cilium , microbiology and biotechnology , hedgehog , ubiquitin ligase , intraflagellar transport , hedgehog signaling pathway , basal body , ubiquitin , signal transduction , mutant , genetics , flagellum , gene
The Hedgehog pathway, critical to vertebrate development, is organized in primary cilia. Activation of signaling causes the Hedgehog receptor Ptch1 to exit cilia, allowing a second receptor, Smo, to accumulate in cilia and activate the downstream steps of the pathway. Mechanisms regulating the dynamics of these receptors are unknown, but the ubiquitination of Smo regulates its interaction with the intraflagellar transport system to control ciliary levels. A focused screen of ubiquitin-related genes identified nine required for maintaining low ciliary Smo at the basal state. These included cytoplasmic E3s (Arih2, Mgrn1, and Maea), a ciliary localized E3 (Wwp1), a ciliary localized E2 (Ube2l3), a deubiquitinase (Bap1), and three adaptors (Kctd5, Skp1a, and Skp2). The ciliary E3, Wwp1, binds Ptch1 and localizes to cilia at the basal state. Activation of signaling removes both Ptch1 and Wwp1 from cilia, thus providing an elegant mechanism for Ptch1 to regulate ciliary Smo levels.