Wnt-5a induces Dishevelled phosphorylation and dopaminergic differentiation via a CK1-dependent mechanism.
Previously, we have shown that Wnt-5a strongly regulates dopaminergic neuron differentiation by inducing phosphorylation of Dishevelled (Dvl). Here, we identify additional components of the Wnt-5a-Dvl pathway in dopaminergic cells. Using in vitro gain-of-function and loss-of-function approaches, we reveal that casein kinase 1 (CK1) delta and CK1epsilon are crucial for Dvl phosphorylation by non-canonical Wnts. We show that in response to Wnt-5a, CK1epsilon binds Dvl and is subsequently phosphorylated. Moreover, in response to Wnt-5a or CK1epsilon, the distribution of Dvl changed from punctate to an even appearance within the cytoplasm. The opposite effect was induced by a CK1epsilon kinase-dead mutant or by CK1 inhibitors. As expected, Wnt-5a blocked the Wnt-3a-induced activation of beta-catenin. However, both Wnt-3a and Wnt-5a activated Dvl2 by a CK1-dependent mechanism in a cooperative manner. Finally, we show that CK1 kinase activity is necessary for Wnt-5a-induced differentiation of primary dopaminergic precursors. Thus, our data identify CK1 as a component of Wnt-5a-induced signalling machinery that regulates dopaminergic differentiation, and suggest that CK1delta/epsilon-mediated phosphorylation of Dvl is a common step in both canonical and non-canonical Wnt signalling.
Bryja
Vítezslav
V
Laboratory of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 77 Stockholm, Sweden.
Schulte
Gunnar
G
Rawal
Nina
N
Grahn
Alexandra
A
Arenas
Ernest
E
D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D000818:Animals; D047389:Casein Kinase I / Q000378:metabolism*; D002454:Cell Differentiation / Q000187:drug effects*; D002460:Cell Line; D002478:Cells, Cultured; D000072261:Dishevelled Proteins; D007150:Immunohistochemistry; D007700:Kinetics; D008636:Mesencephalon / Q000166:cytology / Q000196:embryology; D051379:Mice; D008954:Models, Biological; D009474:Neurons / Q000166:cytology / Q000187:drug effects*; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D051153:Wnt Proteins / Q000494:pharmacology*; D000071818:Wnt-5a Protein
D048868:Adaptor Proteins, Signal Transducing; D000072261:Dishevelled Proteins; C000606582:Dvl2 protein, mouse; D010750:Phosphoproteins; D051153:Wnt Proteins; D000071818:Wnt-5a Protein; C438615:Wnt5a protein, mouse; D047389:Casein Kinase I