The centrosomal deubiquitylase USP21 regulates Gli1 transcriptional activity and stability.
USP21 is a centrosome-associated deubiquitylase (DUB) that has been implicated in the formation of primary cilia - crucial organelles for the regulation of the Hedgehog (Hh) signaling pathway in vertebrates. Here, we identify KCTD6 - a cullin-3 E3-ligase substrate adapter that has been previously linked to Hh signaling - as well as Gli1, the key transcription factor responsible for Hh signal amplification, as new interacting partners of USP21. We identify a cryptic structured protein interaction domain in KCTD6, which is predicted to have a similar fold to Smr domains. Importantly, we show that both depletion and overexpression of catalytically active USP21 suppress Gli1-dependent transcription. Gli proteins are negatively regulated through protein kinase A (PKA)-dependent phosphorylation. We provide evidence that USP21 recruits and stabilises Gli1 at the centrosome where it promotes its phosphorylation by PKA. By revealing an intriguing functional pairing between a spatially restricted deubiquitylase and a kinase, our study highlights the centrosome as an important hub for signal coordination.
Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown Street, Liverpool L69 3BX, UK urbe@liverpool.ac.uk clague@liverpool.ac.uk cheride@liverpool.ac.uk.
Claire
C
Heride
Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK.
Daniel J
DJ
Rigden
Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown Street, Liverpool L69 3BX, UK.
Erithelgi
E
Bertsoulaki
Department of Molecular Medicine, Sapienza University of Rome, 00161 Rome, Italy.
Danilo
D
Cucchi
Department of Experimental Medicine, Sapienza University of Rome, 00161 Rome, Italy.
Enrico
E
De Smaele
Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown Street, Liverpool L69 3BX, UK urbe@liverpool.ac.uk clague@liverpool.ac.uk cheride@liverpool.ac.uk.
Michael J
MJ
Clague
Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown Street, Liverpool L69 3BX, UK urbe@liverpool.ac.uk clague@liverpool.ac.uk cheride@liverpool.ac.uk.
Sylvie
S
Urbé
D048868:Adaptor Proteins, Signal Transducing / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D018385:Centrosome / Q000378:metabolism*; D044842:Cullin Proteins / Q000378:metabolism; D055786:Gene Knockout Techniques; D015723:Gene Library; D053823:Hedgehog Proteins / Q000378:metabolism; D006801:Humans; D051379:Mice; D041681:NIH 3T3 Cells; D010766:Phosphorylation; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D055550:Protein Stability; D015398:Signal Transduction; D015533:Transcriptional Activation / Q000235:genetics*; D020798:Two-Hybrid System Techniques; D043222:Ubiquitin Thiolesterase / Q000378:metabolism*; D000071676:Zinc Finger Protein GLI1 / Q000235:genetics* / Q000378:metabolism
D048868:Adaptor Proteins, Signal Transducing; D044842:Cullin Proteins; C400551:GLI1 protein, human; C498520:Gli1 protein, mouse; D053823:Hedgehog Proteins; C559190:KCTD6 proetin, human; C408875:USP21 protein, human; C584021:Usp16 protein, mouse; D000071676:Zinc Finger Protein GLI1; D043222:Ubiquitin Thiolesterase
DUB; Gli1; Hedgehog; PKA; Phosphorylation; Ubiquitin