The role of direct heparan sulfate interactions and Ca2+ complexation in Hedgehog gradient formation in vivo
Hedgehog (Hh) proteins are morphogens, which play a central role in cell fate decision making, growth and patterning of different tissues, by forming a highly regulated gradient. The precise mechanisms by which Hh transport and signaling are established and regulated remain elusive. A further essential factor for unimpaired Hh functionality are cell surface heparan sulfate proteoglycans (HSPG), which facilitate multimeric cluster formation and play crucial roles in Hh gradient formation. In this work the nature of the Hh/HSPG interactions, as well as an involvement of, in Hh complexed Ca2+ will be characterized, with and overall focus on the in vivo model Drosophila melanogaster.