Professor Gopal Sapkota
Understanding mechanisms of reversible phosphorylation and ubiquitylation in cell signalling and disease.
Reversible phosphorylation and ubiquitylation of proteins underpin the regulation of many cell signalling processes. Faulty signalling cascades account for many human diseases, including skin and bone disorders, cancer and neurodegenerative diseases.
Our group focusses on two key areas of research:
A: FAM83 family as key regulators CK1 isoforms: The CK1 family of constitutively active protein kinases controls a plethora of cellular processes and their misregulation is associated with many human diseases, yet the regulation of CK1 activity, substrate specificity, subcellular localisation and turnover are still understood poorly. Building on our recent discoveries, the research in our group is exploring the hypothesis that the family of FAM83 proteins are key regulators of CK1 isoforms, which act by directing specific CK1 isoforms to distinct subcellular compartments and substrates. We have shown that FAM83G (aka PAWS1) mediates Wnt signalling through association with CK1α. Moreover, pathogenic PAWS1 mutations that cause palmoplantar hyperkeratosis are unable to interact with CK1α, and consequently fail to mediate Wnt signalling. We have also shown that FAM83D directs CK1α to the mitotic spindle to ensure proper spindle positioning and timely cell division.
We aim to continue to dissect the roles of FAM83 proteins in CK1 biology and human diseases. Some key research objectives are:
- Understand the molecular basis of FAM83-CK1 interaction.
- Identify, and characterise the roles of, PAWS1-dependent CK1α substrates in Wnt signalling and FAM83D-dependent CK1α substrates in mitosis.
- Delineate the molecular mechanisms by which other FAM83 proteins direct specific CK1 isoforms to specific subcellular compartments and substrates in response to different signalling cues.
B: Harnessing the ubiquitin proteasome system for drug discovery: Efficient targeted proteolysis of endogenous proteins is desirable in therapeutics and as a research toolkit. Gene knockouts are irreversible and, for many proteins, not feasible. Similarly, RNA interference approaches necessitate prolonged treatments, can lead to incomplete knockdowns and are often associated with off-target effects. Direct proteolysis of target proteins can overcome these limitations. Our lab has developed the Affinity-directed PROtein Missile (AdPROM) System to target endogenous proteins for efficient degradation. We aim to develop this system further to engineer highly efficient inducible AdPROM as well as adapt it to rapidly establish the best E3 ligases for most efficient degradation of target proteins. We want to exploit AdPROM to rapidly test the druggability of so-called “undruggable” targets by proteolysis. We will also explore the therapeutic potential of AdPROM in clearing misfolded proteins that are hallmarks of many neurodegenerative diseases.
MRes Cancer Biology
BSc Advanced Cell Signalling
Top 10 Publications
1. Dunbar K, Jones RA, Dingwell K, Macartney TJ, Smith JC, Sapkota GP (2020). FAM83F regulates canonical Wnt signalling through an interaction with CK1α. Life Sci Alliance. Dec 24;4(2):e202000805. doi: 10.26508/lsa.202000805. Print 2021 Feb. PMID: 33361109.
2. Dunbar K, Macartney TJ, Sapkota GP (2020). IMiDs induce FAM83F degradation via an interaction with CK1α to attenuate Wnt signalling. Life Sci Alliance. Dec 23;4(2):e202000804. doi: 10.26508/lsa.202000804. Print 2021 Feb. PMID: 33361334.
3. Simpson LM, Macartney TJ, Nardin A, Fulcher LJ, Röth S, Testa A, Maniaci C, Ciulli A, Ganley IG, & Sapkota GP (2020). Inducible Degradation of Target Proteins through a Tractable Affinity-Directed Protein Missile System. Cell Chem Biol. 2020 Jul 3: S2451-9456(20)30236-1. doi: 10.1016/j.chembiol.2020.06.013. (PMID: 32668203)
4. Röth S, Macartney TJ, Konopacka A, Chan KH, Zhou H, Queisser MA, & Sapkota GP (2020). Targeting Endogenous K-RAS for Degradation through the Affinity-Directed Protein Missile System. Cell Chem Biol. 2020 Jul 3: S2451-9456(20)30235-X. doi: 10.1016/j.chembiol.2020.06.012. (PMID: 32668202)
5. Tachie-Menson T, Gázquez-Gutiérrez A, Fulcher LJ, Macartney TJ, Wood NT, Varghese J, Gourlay R, Soares RF, Sapkota GP (2020) Characterisation of the biochemical and cellular roles of native and pathogenic amelogenesis imperfecta mutants of FAM83H. Cell Signal. Aug;72:109632. doi: 10.1016/j.cellsig.2020.109632. PMID: 32289446
6. Hutchinson L.D., Darling, N.J., Nicolaou S., Gori I., Squair D.R., Cohen P., Hill C.S. and Sapkota G.P. (2020) Salt-inducible kinases (SIKs) regulate TGFβ-mediated transcriptional and apoptotic responses Cell Death & Disease, Jan 22;11(1):49. doi: 10.1038/s41419-020-2241-6.
7. Wu KZL, Jones RA, Tachie-Menson T, Macartney TJ, Wood NT, Varghese J, Gourlay R, Soares RF, Smith JC, Sapkota GP. (2019) Pathogenic FAM83G palmoplantar keratoderma mutations inhibit the PAWS1:CK1α association and attenuate Wnt signalling. Wellcome Open Res. 2019 Sep 9;4:133. doi: 10.12688/wellcomeopenres.15403.1. eCollection 2019.
8. Fulcher LJ, He Z, Mei L, Macartney TJ, Wood NT, Prescott AR, Whigham AJ, Varghese J, Gourlay R, Ball G, Clarke R, Campbell DG, Maxwell CA, and Sapkota GP (2019) FAM83D directs protein kinase CK1α to the mitotic spindle for proper spindle positioning. EMBO Rep. 2019 Jul 24:e47495. doi: 10.15252/embr.201847495.
9. Fulcher, L. J., Bozatzi, P., Tachie-Menson, T., Cummins, T. D., Wu, K., Dunbar, K., Shrestha, S., Wood, N., Weidlich, S., Macartney, T. J., Varghese, J., Gourlay, R., Campbell, D. G., Dingwell, K. S., Smith, J. C., Bullock, A., and Sapkota, G. P. (2018) The DUF1669 domain of FAM83 family proteins anchor Casein Kinase 1 isoforms. Sci signalling, Vol. 11, Issue 531, eaao2341 DOI: 10.1126/scisignal.aao2341
10. Bozatzi, P., Dingwell, K. S., Wu, K., Cooper, F., Cummins, T. D., Vogt, J., Wood, N., Macartney, T. J., Varghese, J., Gourlay, R., Campbell, D. G., Smith, J. C., and Sapkota, G. P. (2018) PAWS1/FAM83G controls Wnt signalling through association with Casein Kinase 1 alpha. Embo reports, e44807, DOI 10.15252/embr.201744807
In collaboration with leading pharmaceutical companies via the Division of Signal Transduction Therapy (collaboration with Merck Serono, Boehringer Ingelheim, and GlaxoSmithKline) and Janssen Pharmaceuticals, the research outputs from my group contribute to the drug development programmes against human diseases through sharing of research data and reagents. All our reagents are made available to the wider research community through the MRC PPU Reagents and Services and some have been commercialised via license arrangements with companies such as Millipore, AbCam and Ubiquigent.