WNT-mediated signaling relay in stem cells and oncogenesis - from basic biology to applications

Understanding WNT-FZD specificity and signal specification

Early stage researcher 4 (ESR4) project

Supervision: Gunnar Schulte

Lab webpage:  http://ki.se/research/gunnarschulte

Aim:
Understanding FZD complex formation and its role in signal specification

Methodology:
ESR4 will use live cell imaging methods such as Förster resonance electron transfer (FRET) and fluorescence recovery after photobleaching (FRAP) to assess FZD complex composition and dynamics (collaboration Hoffmann). To assess the role of posttranslational modifications for pathway selection we will identify characterize FZD phosphorylation patterns. Mass spectrometry (international secondment: Bryja) and protein biochemistry will be used to characterize agonist-induced and pathway-selective FZD phosphorylation. FZD phosphopeptide libraries will be synthesised (private sector secondment: Pepscan) to screen antibody libraries for phospho-FZD antibodies (collaboration Isogenica).

Collaborators:
Bryja, Hoffmann, Pepscan, Isogenica

Project goals:
ESR4 will characterize WNT-FZD interaction profiles, identify FZD modifications relevant to signalling and generate pathway-selective phospho-FZD antibodies.

Risk assessment and contingency plans:
Methodology is based on overexpression of tagged proteins. Data will therefore be validated with endogenous proteins in cellular models.

Key publications:

  1. Halleskog C, Dijksterhuis JP, Kilander MB, Becerril-Ortega J, Villaescusa JC, Lindgren E, Arenas E, Schulte G. (2012) Heterotrimeric G protein-dependent WNT-5A signaling to ERK1/2 mediates distinct aspects of microglia proinflammatory transformation. J Neuroinflammation, 9:111.
  2. Schulte G. (2010) International Union of Basic and Clinical Pharmacology. LXXX. The class Frizzled receptors. Pharmacol Rev, 62(4):632-67.
  3. Bryja V, Gradl D, Schambony A, Arenas E, Schulte G. (2007) Beta-arrestin is a necessary component of Wnt/beta-catenin signaling in vitro and in vivo. Proc Natl Acad Sci.,104(16):6690-5.