Splice variants of CK1α and CK1α-like: Comparative analysis of subcellular localization, kinase activity and function in the Wnt signaling pathway
- Members of the casein kinase 1 (CK1) family are important regulators of multiple signaling pathways. CK1α is a well-known negative regulator of the Wnt/β-catenin pathway, which promotes the degradation of β-catenin via its phosphorylation of Ser45. In contrast, the closest paralog of CK1α, CK1α-like, is a poorly characterized kinase of unknown function. In this study, we show that the deletion of CK1α, but not CK1α-like, resulted in a strong activation of the Wnt/β-catenin pathway. Wnt-3a treatment further enhanced the activation, which suggests there are at least two modes, a CK1α-dependent and Wnt-dependent, of β-catenin regulation. Rescue experiments showed that only two out of ten naturally occurring splice CK1α/α-like variants were able to rescue the augmented Wnt/β-catenin signaling caused by CK1α deficiency in cells. Importantly, the ability to phosphorylate β-catenin on Ser45 in the in vitro kinase assay was required but not sufficient for such rescue. Our compound CK1α and GSK3α/β KO models suggest that the additional nonredundant function of CK1α in the Wnt pathway beyond Ser45-β-catenin phosphorylation includes Axin phosphorylation. Finally, we established NanoBRET assays for the three most common CK1α splice variants as well as CK1α-like. Target engagement data revealed comparable potency of known CK1α inhibitors for all CK1α variants but not for CK1α-like. In summary, our work brings important novel insights into the biology of CK1α, including evidence for the lack of redundancy with other CK1 kinases in the negative regulation of the Wnt/β-catenin pathway at the level of β-catenin and Axin.
Author: | Tomáš GybeľORCiD, Štěpán ČadaORCiD, Darja KlementováORCiD, Martin P. SchwalmORCiD, Benedict-Tilman BergerORCiDGND, Marek ŠebestaORCiD, Stefan KnappORCiDGND, Vítězslav BryjaORCiD |
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URN: | urn:nbn:de:hebis:30:3-857670 |
DOI: | https://doi.org/10.1016/j.jbc.2024.107407 |
ISSN: | 0021-9258 |
Pubmed Id: | https://pubmed.ncbi.nlm.nih.gov/38796065 |
Parent Title (English): | Journal of biological chemistry |
Publisher: | American Society for Biochemistry and Molecular Biology Publications |
Place of publication: | Bethesda, Md |
Document Type: | Article |
Language: | English |
Date of Publication (online): | 2024/06/24 |
Date of first Publication: | 2024/05/23 |
Publishing Institution: | Universitätsbibliothek Johann Christian Senckenberg |
Release Date: | 2024/11/29 |
Tag: | Axin; NanoBRET; Wnt pathway; alternative splicing; casein kinase 1 alpha (CK1α); casein kinase 1 alpha-like (CK1α-like); gene knockout; inhibitor; phosphorylation; β-catenin |
Volume: | 300.2024 |
Issue: | 107407 |
Article Number: | 107407 |
Page Number: | 22 |
Institutes: | Biochemie, Chemie und Pharmazie |
Medizin | |
Dewey Decimal Classification: | 5 Naturwissenschaften und Mathematik / 57 Biowissenschaften; Biologie / 570 Biowissenschaften; Biologie |
6 Technik, Medizin, angewandte Wissenschaften / 61 Medizin und Gesundheit / 610 Medizin und Gesundheit | |
Sammlungen: | Universitätspublikationen |
Licence (German): | Creative Commons - CC BY - Namensnennung 4.0 International |