Pilot Project 1 (2019)

A technique to visualize specific cell-surface heparan sulfate proteoglycans in vivo in Drosophila melanogaster

Heparan sulfate (HS) proteoglycans are dynamically expressed at the surface of virtually all cell types and act as essential regulators of growth and differentiation. This is achieved by HS binding to a large number of growth factors, morphogens, proteases, protease inhibitors and structural components of the extracellular matrix [1-3]. Here, the specificity of HS/ligand interactions is achieved by the enormous structural diversity of the HS chains, which, importantly, is not encoded in the genome but is thought to be determined by some unknown mechanism during biosynthesis [1, 2]. Despite the functional importance of dynamic HS modification changes, such as N- and O-sulfation and glucuronic acid epimerization, tools to identify and characterize these changes are currently very limited.

We plan to use cDNAs coding for single chain variable Fragment scFv-GFP constructs already tested in C. elegans for the specific detection of dynamic HS sulfation changes. If expressed using the Gal4/UAS overexpression system, we expect that distinct subcellular HS modification patterns observed in worms will be likewise detected in developing Drosophila tissues.