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Post-Translational Modifications of Β-Catenin and TFC/LEF-1 Regulate Canonical Wnt Signaling Related Publications MARCH Research Tools 2018

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Post-Translational Modifications of Β-Catenin and TFC/LEF-1 Regulate Canonical Wnt Signaling Related Publications MARCH Research Tools 2018 CYTOSKELETON NEWS NEWS FROM CYTOSKELETON INC. Post-translational Modifications of β-catenin and TFC/LEF-1 Regulate Canonical Wnt Signaling Related Publications MARCH Research Tools 2018 v Meetings Post-translational Modifications of β-catenin and TCF/LEF-1 Regulate Canonical Wnt Signaling Boston Area Mitosis and Protein post-translational modifications (PTMs) such as consisting of the scaffolding/tumor suppressor proteins Axin News Meiosis Meeting phosphorylation, acetylation, ubiquitination, and SUMOylation, and adenomatous polyposis coli (APC), and the serine/threonine May 12 to name but a few, have evolved to diversify the functions of kinases casein kinase 1α (CK-1α) and glycogen synthase kinase 3 Boston MA a single protein and account for the vast increase in proteome (GSK3) mediates phosphorylation of β-catenin2,3,9. Under these Cytoskeleton Supported complexity and functional diversity1. A prime example of the quiescent conditions, β-cateinin is sequentially phosphorylated complex and dynamic regulatory power PTMs confer is the on Ser45 by CK-1α, followed by phosphorylation of Ser33, Ser37, GRC Phosphorylation Wnt/β-catenin signaling pathway2,3. This pathway regulates and Thr41 by GSK312 (Fig. 1). Upon phosphorylation, the E3 and G-Protein Mediated cellular proliferation, differentiation, and migration during ubiquitin ligase β-transducin repeats containing protein (β-TrCP) 4-6 13,14 Signaling Networks embryonic development and adult cell homeostasis . In ubiquitinates phospho-β-catenin on Lys19 and Lys49 , which addition, dysregulation of Wnt/β-catenin signaling is implicated leads to proteasomal destruction and low β-catenin levels June 3-8 in multiple pathological conditions, including carcinogenesis and and activity15,16. Conversely, in the presence of Wnt binding, Biddeford, ME degenerative diseases5,7. In canonical Wnt-mediated signaling, the scaffold protein Dishevelled (Dvl) is recruited to the Fz- Cytoskeleton Supported β-catenin is a key effector and interacts, as a co-transcription LRP5/6 co-receptor complex, which activates a sequence of Publications factor, with the DNA binding proteins TCF (T cell factor) and molecular signals that inhibit the destruction complex and GRC Signalling by LEF-1 (lymphoid enhancer factor 1) to activate the transcription result in stabilization of unphosphorylated, cytosolic β-catenin Adhesion Receptors of Wnt/β-catenin target genes including cyclin D1, c-jun, and and β-catenin-dependent transcription2,3,17-19. Stabilization June 24-29 c-myc8-11 (Fig. 1). In this newsletter, the functional regulation of occurs through partial inhibition of CK-1α and GSK318, inhibition Biddeford, ME β-catenin and TCF/LEF-1 by PTMs is discussed. of β-TrCP20, phosphorylation of five highly conserved PPPSP motifs in LRP6's intracellular domain21,22 (Fig.1), and subsequent Cytoskeleton Supported Post-translational regulation of β-catenin in Wnt signaling aggregation of these Wnt signaling proteins. The negative Wnt In the absence of Wnt binding to the co-receptor complex regulator Axin is inhibited through recrutiment and direct Cytoskeleton of Frizzled (Fz) and low-density lipoprotein receptor-related binding to this aggregate complex3,17. Products proteins (LRP) 5 and 6, a multi-protein destruction complex Actin Proteins Activation Assays Antibodies ECM Proteins Research Tools ELISA Kits G-LISA® Kits Pull-down Assays Motor Proteins Small G-Proteins Tubulin & FtsZ Proteins Contact Us P: 1 (303) 322.2254 F: 1 (303) 322.2257 E: [email protected] W: cytoskeleton.com Fig. 1 PTMs regulate the stability of ß-catenin and TCF/LEF-1 and their interaction; (ßBD:ß-catenin binding domain, HMG: High mobility group,↑ : favors interaction, : inhibits interaction). www.cytoskeleton.com Signal-Seeker PRODUCTS Continued from Page 1 References Notably, the same PTMs can inhibit or enhance β-catenin activity, depending on the 1. Prabakaran S. et al. 2012. Post-translational modification: nature's escape from genetic impris- 17 onment and the basis for dynamic information encoding. Wiley Interdiscip. Rev. Syst. Biol. Med. residue(s) modified. For example, ubiquitination of Lys394 stabilizes β-catenin . 4, 565-583. Similarly, phosphorylation of Ser675 by PKA, Ser552 by AKT, and Ser191/605 by 2. Niehrs C. 2012. The complex world of WNT receptor signalling. Nat. Rev. Mol. Cell Biol. 13, JNK2 stabilizes β-catenin23-25 (Fig. 1). Acetyltransferases act on multiple Lys residues 767-779. 3. Gao C. et al. 2014. Regulation of Wnt/beta-catenin signaling by posttranslational modifica- and each acetylation modulates the functional role and stability of β-catenin in tions. Cell Biosci. 4, 13. different ways: acetylation of Lys49 by CBP inhibits β-catenin’s transcription 4. Wodarz A. and Nusse R. 1998. Mechanisms of Wnt signaling in development. Annu. Rev. Cell activity26, acetylation of Lys345 by p300 enhances β-catenin interaction with Dev. Biol. 14, 59-88. TCF27, and acetylation of Lys19 and Lys49 by PCAF increases β-catenin stability28. 5. Polakis P. 2000. Wnt signaling and cancer. Genes Dev. 14, 1837-1851. 17 6. McCrea P.D. and Gottardi C.J. 2016. Beyond beta-catenin: prospects for a larger catenin net- Interestingly, tyrosine phosphorylation seems to only enhance β-catenin activity . work in the nucleus. Nat. Rev. Mol. Cell Biol. 17, 55-64. 7. Nusse R. and Clevers H. 2017. Wnt/β-catenin signaling, disease, and emerging therapeutic Post-translational regulation of TCF/LEF-1 in Wnt signaling modalities. Cell. 169, 985-999. 8. MacDonald B.T. et al. 2009. Wnt/beta-catenin signaling: components, mechanisms, and dis- TCF and LEF-1 form multimeric transcription complexes with cofactors such as eases. Dev. Cell. 17, 9-26. CtBP, HBP1, and β-catenin, which function together to either repress or activate 9. Cong F. et al. 2004. Wnt signals across the plasma membrane to activate the beta-catenin gene expression29,30. The binding affinity between TCF/LEF-1 and co-regulators pathway by forming oligomers containing its receptors, Frizzled and LRP. Development. 131, 5103-5115. is significantly affected by each protein’s respective PTM status (Fig. 1). TCF is 10. Li V.S. et al. 2012. Wnt signaling through inhibition of beta-catenin degradation in an intact phosphorylated on multiple Thr/Ser residues with opposing functional effects. For Axin1 complex. Cell. 149, 1245-1256. instance, phosphorylation of Ser154 on TCF by the TNIK kinase is required for its 11. Ziegler S. et al. 2005. Novel target genes of the Wnt pathway and statistical insights into Wnt target promoter regulation. FEBS J. 272, 1600-1615. transcriptional activity3, while phosphorylation of Thr178 and Thr189 by Nemo- 12. Liu C. et al. 2002. Control of beta-catenin phosphorylation/degradation by a dual-kinase like kinase (NLK) inhibits TCF/DNA binding and suppresses its transcriptional mechanism. Cell. 108, 837-847. activity31. The phosphorylation of TCF by NLK is linked to TCF ubiquitination. LEF- 13. Wu G. et al. 2003. Structure of a β-TrCP1-Skp1-β-catenin complex: destruction motif binding TrCP1 1 is phosphorylated on Thr155 and Ser166 by NLK, which inhibits DNA binding and lysine specificity of the SCF β ubiquitin ligase. Mol. Cell. 11, 1445-1456. 3 14. Winer I.S. et al. 2006. Lysine residues Lys-19 and Lys-49 of β-catenin regulate its levels and of the TCF/LEF-1/β-catenin complex . Conversely, phosphorylation of Ser42 and function in T cell factor transcriptional activation and neoplastic transformation.J. Biol. Chem. Ser61 by CK-1 enhances β-catenin binding and transactivation32. The E3 ligase NLK- 281, 26181-26187. associated Ring Finger Protein (NARF) ubiquitinates TCF/LEF-1 in vitro and in vivo, 15. Aberle H. et al. 1997. Beta-catenin is a target for the ubiquitin-proteasome pathway. EMBO J. 16, 3797-3804. 33 which leads to TCF/LEF-1 degradation . Both TCF and LEF-1 undergo SUMOylation 16. Hart M. et al. 1999. The F-box protein beta-TrCP associates with phosphorylated beta-catenin by PIASy, but the functional consequences are distinct. SUMOylation of Lys297 on and regulates its activity in the cell. Curr. Biol. 9, 207-210. TCF confers enhanced activity34, while SUMOylation of Lys25 and Lys267 residues 17. Valenta T. et al. 2012. The many faces and functions of beta-catenin. EMBO J. 31, 2714-2736. 35 18. Hernandez A.R. et al. 2012. Kinetic responses of beta-catenin specify the sites of Wnt control. on LEF-1 results in loss of activity . Science. 338, 1337-1340. 19. Kim S.E. et al. 2013. Wnt stabilization of beta-catenin reveals principles for morphogen recep- Summary tor-scaffold assemblies. Science. 340, 867-870. 20. Li V.S.W. et al. 2012. Wnt signaling through inhibition of β-catenin degradation in an intact Like most, if not all, proteins, the Wnt signaling effector β-catenin and its co- Axin1 complex. Cell. 149, 1245-1256. transcriptional regulators TCF and LEF-1 are regulated by multiple PTMs, with the 21. MacDonald B.T. et al. 2008. Wnt signal amplification via activity, cooperativity, and regulation same PTM able to both enhance and inhibit activity, depending on which residue(s) of multiple intracellular PPPSP motifs in the Wnt co-receptor LRP6. J. Biol. Chem. 283, 16115- 16123. are modified. In addition, PTMs can be cooperative or mutually exclusive. To study 22. Niehrs C. and Shen J. 2010. Regulation of Lrp6 phosphorylation. Cell Mol. Life Sci. 67, 2551-2562. such complex and diverse functional regulation of cells' proteomes requires 23. Hino S. et al. 2005. Phosphorylation of beta-catenin by cyclic AMP-dependent protein kinase sensitive and quantitative reagents. At Cytoskeleton, Inc., the Signal-Seeker stabilizes beta-catenin through inhibition of its ubiquitination. Mol. Cell Biol. 25, 9063-9072. kits offer an unparalleled view into how PTMs regulate protein localization and 24. Fang D. et al. 2007. Phosphorylation of beta-catenin by AKT promotes beta-catenin transcrip- tional activity. J. Biol. Chem. 282, 11221-11229. function with the ability to measure tyrosine phosphorylation, ubiquitination, 25.
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