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Sorting processes that ensure short and long-range action of Wnts in developing epithelia

Objective

Wnts are signaling proteins that act both at short and long range in developing tissues. Several proteins, such as Wntless, are specifically devoted to Wnt secretion, indicating that Wnts may follow a distinct secretory route. Moreover, Wnts carry two lipid modifications, which are likely to interfere with diffusion in the extracellular space. Much of our work will focus on the trafficking of Wingless (the main Drosophila Wnt), which forms a concentration gradient in wing imaginal discs. To chart the route taken by Wingless from the ER to responding cells, we will devise techniques (e.g. BirA-dependent in vivo biotinylation) to pulse label endogenously expressed Wingless in the secretory pathway and at the cell surface. Wingless routing will also be investigated in conditions that alter Evi/Wntless trafficking. We will capitalize on our observation that Wingless and Wntless are present on exosomes in conditioned medium. These exosomes will be purified and characterized by mass spectrometry and the resulting information will be used to devise rigorous functional assays. Similar approaches will be used to identify and characterize proteins that associate with soluble Wingless, which is also present in conditioned medium. Our proposed approaches will also enable us to assess, for the first time, the function of exosomes in an intact animal. Once secreted, Wingless and associated proteins spread in the extracellular space while remaining associated with the epithelial surface. We will use single molecule imaging in a reconstituted system along with mathematical modeling to test the hypothesis that the glypican-Wnt interaction is sufficiently strong to ensure surface retention while allowing diffusion in two dimensions. Finally we will use biochemical approaches and molecular genetics in Drosophila and mice to investigate the mode of action of Notum, a glypican-modifying enzyme that could be relevant to the progression of Wnt signaling dependent cancers.

Field of science

  • /natural sciences/biological sciences/genetics and heredity
  • /natural sciences/biological sciences/molecular biology/molecular genetics
  • /natural sciences/biological sciences/biochemistry/biomolecules/proteins
  • /natural sciences/chemical sciences/analytical chemistry/mass spectrometry
  • /natural sciences/mathematics/applied mathematics/mathematical model

Call for proposal

ERC-2011-ADG_20110310
See other projects for this call

Funding Scheme

ERC-AG - ERC Advanced Grant

Host institution

THE FRANCIS CRICK INSTITUTE LIMITED
Address
1 Midland Road
NW1 1AT London
United Kingdom
Activity type
Research Organisations
EU contribution
€ 1 938 845,57
Principal investigator
Jean-Paul B.B. Vincent (Dr.)
Administrative Contact
Stéphane Maikovsky (Mr.)

Beneficiaries (2)

THE FRANCIS CRICK INSTITUTE LIMITED
United Kingdom
EU contribution
€ 1 938 845,57
Address
1 Midland Road
NW1 1AT London
Activity type
Research Organisations
Principal investigator
Jean-Paul B.B. Vincent (Dr.)
Administrative Contact
Stéphane Maikovsky (Mr.)
MEDICAL RESEARCH COUNCIL
United Kingdom
Address
North Star Avenue Polaris House 2 Floor David Phillips Building
SN2 1FL Swindon
Activity type
Research Organisations
Administrative Contact
David Jones (Mr.)