1. Dishevelled internal affairs in WNT signalling
Supervisor : Konstantinos Tripsianes, Ph.D.
Annotation :
Dishevelled (DVL) is the central hub of Wnt signal transduction that integrates and transduces upstream signals through distinct cytoplasmic cascades. Looking at the many DVL faces reported in the literature, three salient features underlying its function in signalling can be highlighted: (1) it interacts with more than seventy binding partners, (2) it is heavily phosphorylated at multiple sites by at least eight different kinases, in particular by Ck1ε/δ after Wnt stimulation, and (3) it consistently forms puncta in the cytosol, that are phase-separated self-assemblies also called liquid droplets.
Our working hypothesis is that DVL conformational plasticity mediated by the order-disorder interactions allows the combinatorial integration of phosphorylation input, partners binding, self-assembly in droplets, and allosteric coupling, to exquisitely control signal routing. We integrate structural biology (NMR, SAXS, X-ray) and biophysical techniques (FRET, ITC, BLI) with cellular readouts (TopFlash, BRET) to understand DVL structure, function, and regulation. Candidates can choose among three open questions, that if resolved, will have a significant impact on Wnt research.
1) Does disorder provide new contexts to structured domain(s) and, hence, enhance the DVL functional space associated with them?
2) Is there a direction, order or hierarchy in the phosphorylation of individual S/T sites and clusters in DVL?
3) What are the physical behaviours associated with the intrinsic disorder and their connection to DVL liquid-liquid phase separation?
Requirements on candidates:
- Biomolecular NMR
- Biochemistry
- Molecular Cell Biology
Recommended literature :
- Hanáková K., Bernatík O., Kravec M., Micka M., Kumar J., Harnoš J., Ovesná P., Paclíková P., Rádsetoulal M., Potěšil D., Tripsianes K., Čajánek L., Zdráhal Z.*, Bryja V.*, Comparative phosphorylation map of Dishevelled 3 links phospho-signatures to biological outputs. Cell Commun. Signal., 2019. 17: p. 170
- Harnoš J., Cañizal M.C.A., Jurásek M., Kumar J., Holler C., Schambony A., Hanáková K., Bernatík O., Zdráhal Z., Gömöryová K., Gybeľ T., Radaszkiewicz T.W., Kravec M., Trantírek L., Ryneš J., Dave Z., Fernández-Llamazares A.I., Vácha R., Tripsianes K., Hoffmann C., Bryja V.*, Dishevelled-3 conformation dynamics analyzed by FRET-based biosensors reveals a key role of casein kinase 1. Nat. Commun., 2019. 10: p. 1804.
Keywords: Wnt signalling, Dishevelled, Casein kinase, interactions, conformations, phosphorylations, dynamics, allostery, NMR, X-ray crystallography, SAXS, FRET, cryo-EM, native MS, MS-HDX.
