{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,19]],"date-time":"2026-09-19T09:41:02Z","timestamp":1789810862716,"version":"4.0.1"},"reference-count":56,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2025,11,18]],"date-time":"2025-11-18T00:00:00Z","timestamp":1763424000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"UKRI Medical Research Council","award":["MC_UU_00038\/6"],"award-info":[{"award-number":["MC_UU_00038\/6"]}]},{"name":"University of Dundee\u2019s Black British Scholarship Programme"},{"name":"MRC PPU Prize PhD studentship"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>The dysregulation of CK1 isoforms is linked to various types of diseases, including neurodegeneration and different types of neoplasia such as colon, pancreatic, breast, and ovarian cancer. For CK1 isoforms, a plethora of effective small molecule inhibitors are available. However, only a few degraders of CK1\u03b1 and, more recently, proteolysis targeting chimeras (PROTACs) for CK1\u03b4\/CK1\u03b5 have been reported. In this study, we applied the PROTAC concept by harnessing molecular modelling to design and synthesize a series of candidate CK1\u03b4-targeting PROTACs based on a highly specific and potent benzothiazole-based CK1\u03b4 inhibitor that we previously developed in our lab. In the present study, we established a modular synthetic platform to systematically generate a set of PROTAC degrader candidates consisting of the CK1\u03b4-specific inhibitor scaffold, alkyl and PEG linker motifs with various lengths, and Cereblon (CRBN)-engaging pomalidomide and thalidomide derivatives as E3 ligase binders. We demonstrate that several PROTACs degrade CK1\u03b4\/\u03b5 in various cells. The most potent PROTAC P1d inhibits the phosphorylation of downstream substrates through CK1\u03b4\/\u03b5 degradation. We establish the requirement of CUL4ACRBN and the proteasome for the P1d-mediated degradation of CK1\u03b4\/\u03b5.<\/jats:p>","DOI":"10.3390\/molecules30224452","type":"journal-article","created":{"date-parts":[[2025,11,18]],"date-time":"2025-11-18T16:49:51Z","timestamp":1763484591000},"page":"4452","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Design and Synthesis of Novel Candidate CK1\u03b4 Proteolysis Targeting Chimeras (PROTACs)"],"prefix":"10.3390","volume":"30","author":[{"ORCID":"https:\/\/orcid.org\/0009-0009-5352-8515","authenticated-orcid":false,"given":"Malte","family":"Arnold","sequence":"first","affiliation":[{"name":"Institute of Pharmacy, Department of Pharmaceutical and Medicinal Chemistry, Christian-Albrechts-University of Kiel, 24118 Kiel, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Temi","family":"Thompson","sequence":"additional","affiliation":[{"name":"MRC Protein Phosphorylation and Ubiquitylation Unit, Sir James Black Centre, School of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lorraine","family":"Glennie","sequence":"additional","affiliation":[{"name":"MRC Protein Phosphorylation and Ubiquitylation Unit, Sir James Black Centre, School of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mattes","family":"Hollnagel","sequence":"additional","affiliation":[{"name":"Institute of Pharmacy, Department of Pharmaceutical and Medicinal Chemistry, Christian-Albrechts-University of Kiel, 24118 Kiel, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9931-3338","authenticated-orcid":false,"given":"Gopal","family":"Sapkota","sequence":"additional","affiliation":[{"name":"MRC Protein Phosphorylation and Ubiquitylation Unit, Sir James Black Centre, School of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1532-7826","authenticated-orcid":false,"given":"Christian","family":"Peifer","sequence":"additional","affiliation":[{"name":"Institute of Pharmacy, Department of Pharmaceutical and Medicinal Chemistry, Christian-Albrechts-University of Kiel, 24118 Kiel, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,11,18]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"181","DOI":"10.1038\/s41573-021-00371-6","article-title":"PROTAC targeted protein degraders: The past is prologue","volume":"21","author":"Langley","year":"2022","journal-title":"Nat. Rev. Drug Discov."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"5214","DOI":"10.1039\/D2CS00193D","article-title":"PROTACs: Past, present and future","volume":"51","author":"Li","year":"2022","journal-title":"Chem. Soc. Rev."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"998","DOI":"10.1016\/j.chembiol.2020.07.020","article-title":"PROTACs: An Emerging Therapeutic Modality in Precision Medicine","volume":"8","author":"Nalawansha","year":"2020","journal-title":"Cell Chem. Biol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"425","DOI":"10.1146\/annurev.biochem.67.1.425","article-title":"The ubiquitin system","volume":"67","author":"Hershko","year":"1998","journal-title":"Annu. Rev. Biochem."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"352","DOI":"10.1016\/j.tcb.2013.12.003","article-title":"Perilous journey: A tour of the ubiquitin-proteasome system","volume":"6","author":"Kleiger","year":"2014","journal-title":"Trends Cell Biol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1007\/BF02705243","article-title":"The ubiquitin-proteasome system","volume":"31","author":"Nandi","year":"2006","journal-title":"J. Biosci."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"405","DOI":"10.1021\/acs.jmedchem.6b01346","article-title":"Regulating the Master Regulator: Controlling Ubiquitination by Thinking Outside the Active Site","volume":"2","author":"Paiva","year":"2018","journal-title":"J. Med. Chem."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1242","DOI":"10.1038\/nm.3739","article-title":"Ubiquitination in disease pathogenesis and treatment","volume":"20","author":"Popovic","year":"2014","journal-title":"Nat. Med."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"419","DOI":"10.1097\/01.mop.0000133634.79661.cd","article-title":"Human disorders of ubiquitination and proteasomal degradation","volume":"4","author":"Jiang","year":"2004","journal-title":"Curr. Opin. Pediatr."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1016\/j.cbpa.2019.02.022","article-title":"Targeted protein degradation: Elements of PROTAC design","volume":"50","author":"Paiva","year":"2019","journal-title":"Curr. Opin. Chem. Biol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"553","DOI":"10.1016\/j.ebiom.2018.09.005","article-title":"Small-molecule PROTACs: An emerging and promising approach for the development of targeted therapy drugs","volume":"36","author":"An","year":"2018","journal-title":"EBioMedicine"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"301","DOI":"10.1038\/nsmb.2780","article-title":"New insights into ubiquitin E3 ligase mechanism","volume":"21","author":"Berndsen","year":"2014","journal-title":"Nat. Struct. Mol. Biol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"163","DOI":"10.1016\/j.bbamcr.2013.03.019","article-title":"Substrate recognition in selective autophagy and the ubiquitin-proteasome system","volume":"1","author":"Schreiber","year":"2014","journal-title":"Biochim. Biophys. Acta"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Alabi, S.B., and Crews, C.M. (2021). Major advances in targeted protein degradation: PROTACs, LYTACs, and MADTACs. J. Biol. Chem., 296.","DOI":"10.1016\/j.jbc.2021.100647"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"611","DOI":"10.1038\/nchembio.1858","article-title":"Catalytic in vivo protein knockdown by small-molecule PROTACs","volume":"11","author":"Bondeson","year":"2015","journal-title":"Nat. Chem. Biol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"381","DOI":"10.37349\/etat.2020.00023","article-title":"Novel approaches for the rational design of PROTAC linkers","volume":"1","author":"Zagidullin","year":"2020","journal-title":"Explor. Target. Anti-Tumor Ther."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"273","DOI":"10.37349\/etat.2020.00018","article-title":"Current strategies for the design of PROTAC linkers: A critical review","volume":"1","author":"Troup","year":"2020","journal-title":"Explor. Target. Anti-Tumor Ther."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"681","DOI":"10.1021\/acsmedchemlett.5c00068","article-title":"Linker-Determined Folding and Hydrophobic Interactions Explain a Major Difference in PROTAC Cell Permeability","volume":"16","author":"Poongavanam","year":"2025","journal-title":"ACS Med. Chem. Lett."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"359","DOI":"10.1039\/C0MB00074D","article-title":"Impact of linker length on the activity of PROTACs","volume":"7","author":"Cyrus","year":"2011","journal-title":"Mol. Biosyst."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Knippschild, U., Kr\u00fcger, M., Richter, J., Xu, P., Garc\u00eda-Reyes, B., Peifer, C., Halekotte, J., Bakulev, V., and Bischof, J. (2014). The CK1 Family: Contribution to Cellular Stress Response and Its Role in Carcinogenesis. Front. Oncol., 4.","DOI":"10.3389\/fonc.2014.00096"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"5986","DOI":"10.1073\/pnas.1721076115","article-title":"CK1\u03b4\/\u03b5 protein kinase primes the PER2 circadian phosphoswitch","volume":"23","author":"Narasimamurthy","year":"2018","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Sinnberg, T., Wang, J., Sauer, B., and Schittek, B. (2016). Casein kinase 1\u03b1 has a non-redundant and dominant role within the CK1 family in melanoma progression. BMC Cancer, 16.","DOI":"10.1186\/s12885-016-2643-0"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"4603","DOI":"10.1042\/BCJ20200506","article-title":"Functions and regulation of the serine\/threonine protein kinase CK1 family: Moving beyond promiscuity","volume":"23","author":"Fulcher","year":"2020","journal-title":"Biochem. J."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Gybe\u013e, T., \u010cada, \u0160., Klementov\u00e1, D., Schwalm, M.P., Berger, B.-T., \u0160ebesta, M., Knapp, S., and Bryja, V. (2024). Splice variants of CK1\u03b1 and CK1\u03b1-like: Comparative analysis of subcellular localization, kinase activity, and function in the Wnt signaling pathway. J. Biol. Chem., 7.","DOI":"10.1016\/j.jbc.2024.107407"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1038\/s41392-021-00762-6","article-title":"Wnt\/\u03b2-catenin signalling: Function, biological mechanisms, and therapeutic opportunities","volume":"7","author":"Liu","year":"2022","journal-title":"Signal Transduct. Target. Ther."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1016\/j.devcel.2009.06.016","article-title":"Wnt\/beta-catenin signaling: Components, mechanisms, and diseases","volume":"1","author":"MacDonald","year":"2009","journal-title":"Dev. Cell"},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Bryja, V., and Bernat\u00edk, O. (2014). Dishevelled at the Crossroads of Pathways. Wnt Signaling in Development and Disease: Molecular Mechanisms and Biological Functions, Wiley.","DOI":"10.1002\/9781118444122.ch15"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"144005","DOI":"10.1016\/j.gene.2019.144005","article-title":"Structure, regulation, and (patho-)physiological functions of the stress-induced protein kinase CK1 delta (CSNK1D)","volume":"715","author":"Xu","year":"2019","journal-title":"Gene"},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Mazzoldi, E.L., Past\u00f2, A., Ceppelli, E., Pilotto, G., Barbieri, V., Amadori, A., and Pavan, S. (2019). Casein Kinase 1 Delta Regulates Cell Proliferation, Response to Chemotherapy and Migration in Human Ovarian Cancer Cells. Front. Oncol., 9.","DOI":"10.3389\/fonc.2019.01211"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"465","DOI":"10.1016\/j.biocel.2010.12.004","article-title":"Casein kinase 1: Complexity in the family","volume":"4","author":"Cheong","year":"2011","journal-title":"Int. J. Biochem. Cell Biol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1692","DOI":"10.1021\/acsmedchemlett.4c00250","article-title":"Structure\u2013Activity Relationship of Potent, Selective, and Orally Bioavailable Molecular Glue Degraders of CK1\u03b1","volume":"15","author":"Nishiguchi","year":"2024","journal-title":"ACS Med. Chem. Lett."},{"key":"ref_32","unstructured":"(2025, March 06). MedchemExpress.com. Available online: https:\/\/www.medchemexpress.com\/ck1%CE%B1-degrader-1.html."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Wang, K., Jiang, M., Liu, H., Meng, C., Li, M., and Lu, H. (2024). Discovery of novel co-degradation CK1\u03b1 and CDK7\/9 PROTACs with p53 activation for treating acute myeloid leukemia. Bioorganic Chem., 147.","DOI":"10.1016\/j.bioorg.2024.107319"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"506","DOI":"10.1021\/acs.jmedchem.4c02201","article-title":"Development and Discovery of a Selective Degrader of Casein Kinases 1 \u03b4\/\u03b5","volume":"1","author":"Haag","year":"2025","journal-title":"J. Med. Chem."},{"key":"ref_35","first-page":"4087","article-title":"Discovery of Inhibitor of Wnt Production 2 (IWP-2) and Related Compounds As Selective ATP-Competitive Inhibitors of Casein Kinase 1 (CK1) \u03b4\/\u03b5","volume":"9","author":"Witt","year":"2018","journal-title":"J. Med. Chem."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Liu, C., Witt, L., Ianes, C., Bischof, J., Bammert, M.-T., Baier, J., Kirschner, S., Henne-Bruns, D., Xu, P., and Kornmann, M. (2019). Newly Developed CK1-Specific Inhibitors Show Specifically Stronger Effects on CK1 Mutants and Colon Cancer Cell Lines. Int. J. Mol. Sci., 20.","DOI":"10.3390\/ijms20246184"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"9451","DOI":"10.1021\/acs.jmedchem.5b00446","article-title":"Medicinal Chemistry Approaches to Heart Regeneration","volume":"24","author":"Schade","year":"2015","journal-title":"J. Med. Chem."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"100","DOI":"10.1038\/nchembio.137","article-title":"Small molecule-mediated disruption of Wnt-dependent signaling in tissue regeneration and cancer","volume":"5","author":"Chen","year":"2009","journal-title":"Nat. Chem. Biol."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"1577","DOI":"10.1007\/s00726-012-1234-x","article-title":"2-Benzamido-N-(1H-benzodimidazol-2-yl)thiazole-4-carboxamide derivatives as potent inhibitors of CK1\u03b4\/\u03b5","volume":"43","author":"Bischof","year":"2012","journal-title":"Amino Acids"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"638","DOI":"10.1021\/acs.jmedchem.4c02492","article-title":"Impact of Linker Composition on VHL PROTAC Cell Permeability","volume":"1","author":"Abeje","year":"2025","journal-title":"J. Med. Chem."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"127","DOI":"10.1038\/nature16979","article-title":"Structural basis of lenalidomide-induced CK1\u03b1 degradation by the CRL4(CRBN) ubiquitin ligase","volume":"532","author":"Petzold","year":"2016","journal-title":"Nature"},{"key":"ref_42","first-page":"2975","article-title":"Synthesis and in vitro trichomonicidal, giardicidal and amebicidal activity of N-acetamide(sulfonamide)-2-methyl-4-nitro-1H-imidazoles","volume":"7","author":"Tlahuext","year":"2009","journal-title":"Eur. J. Med. Chem."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"2309","DOI":"10.1016\/j.tetlet.2010.02.128","article-title":"Fe nano particles mediated C\u2013N bond-forming reaction: Regioselective synthesis of 3-[(2-chloroquinolin-3-yl)methyl]pyrimidin-4(3H)ones","volume":"17","author":"Roopan","year":"2010","journal-title":"Tetrahedron Lett."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"239","DOI":"10.1055\/s-1995-4931","article-title":"A New and Convenient Synthesis of Imidazole-2-thiones from Imidazoles","volume":"1995","author":"Xu","year":"1995","journal-title":"Synlett"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"6162","DOI":"10.1021\/jo070641d","article-title":"Synthesis and self-association properties of flexible guanidiniocarbonylpyrrole-carboxylate zwitterions in DMSO: Intra- versus intermolecular ion pairing","volume":"16","author":"Schmuck","year":"2007","journal-title":"J. Org. Chem."},{"key":"ref_46","doi-asserted-by":"crossref","unstructured":"Kim, K., Lee, D.H., Park, S., Jo, S.-H., Ku, B., Park, S.G., Park, B.C., Jeon, Y.U., Ahn, S., and Kang, C.H. (2019). Disordered region of cereblon is required for efficient degradation by proteolysis-targeting chimera. Sci. Rep., 1.","DOI":"10.1038\/s41598-019-56177-5"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"152719","DOI":"10.1016\/j.tetlet.2020.152719","article-title":"Synthesis of amide derivatives for electron deficient amines and functionalized carboxylic acids using EDC and DMAP and a catalytic amount of HOBt as the coupling reagents","volume":"63","author":"Ghosh","year":"2021","journal-title":"Tetrahedron Lett."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"17019","DOI":"10.1021\/jacs.8b08008","article-title":"Addressing Kinase-Independent Functions of Fak via PROTAC-Mediated Degradation","volume":"49","author":"Cromm","year":"2018","journal-title":"J. Am. Chem. Soc."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"2","DOI":"10.1186\/s12964-014-0079-1","article-title":"Asymmetry of VANGL2 in migrating lymphocytes as a tool to monitor activity of the mammalian WNT\/planar cell polarity pathway","volume":"13","author":"Petersen","year":"2015","journal-title":"Cell Commun. Signal. CCS"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"1466","DOI":"10.1038\/cr.2017.127","article-title":"Wnt-induced Vangl2 phosphorylation is dose-dependently required for planar cell polarity in mammalian development","volume":"27","author":"Yang","year":"2017","journal-title":"Cell Res."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"eaao2341","DOI":"10.1126\/scisignal.aao2341","article-title":"The DUF1669 domain of FAM83 family proteins anchor casein kinase 1 isoforms","volume":"11","author":"Fulcher","year":"2018","journal-title":"Sci. Signal."},{"key":"ref_52","doi-asserted-by":"crossref","unstructured":"Glennie, L., Curnutt, N., Cartwright, T., Dunbar, K., Le Chatelier, B., Wood, N.T., Macartney, T.J., Woo, C.M., and Sapkota, G.P. (2025). The contribution of native protein complexes to targeted protein degradation. BioRxiv, preprint.","DOI":"10.1101\/2025.06.17.660125"},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"221","DOI":"10.1007\/s10822-013-9644-8","article-title":"Protein and ligand preparation: Parameters, protocols, and influence on virtual screening enrichments","volume":"27","author":"Sastry","year":"2013","journal-title":"J. Comput.-Aided Mol. Des."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"440","DOI":"10.1002\/jcc.540110405","article-title":"Macromodel\u2014An integrated software system for moedling organic and bioorganic molecules using molecular mechanics","volume":"4","author":"Mohamadi","year":"1990","journal-title":"J. Comput. Chem."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"1739","DOI":"10.1021\/jm0306430","article-title":"Glide: A New Approach for Rapid, Accurate Docking and Scoring. 1. Method and Assessment of Docking Accuracy","volume":"7","author":"Friesner","year":"2004","journal-title":"J. Med. Chem."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"e202000805","DOI":"10.26508\/lsa.202000805","article-title":"FAM83F regulates canonical Wnt signalling through an interaction with CK1\u03b1","volume":"4","author":"Dunbar","year":"2021","journal-title":"Life Sci. Alliance"}],"container-title":["Molecules"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1420-3049\/30\/22\/4452\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,11,19]],"date-time":"2025-11-19T08:50:19Z","timestamp":1763542219000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1420-3049\/30\/22\/4452"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,11,18]]},"references-count":56,"journal-issue":{"issue":"22","published-online":{"date-parts":[[2025,11]]}},"alternative-id":["molecules30224452"],"URL":"https:\/\/doi.org\/10.3390\/molecules30224452","relation":{},"ISSN":["1420-3049"],"issn-type":[{"value":"1420-3049","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,11,18]]}}}