Molecular Parameters for the Dynamic Assembly of Hedgehog Signaling Platforms
All Hedgehog (Hh) morphogens are dually lipidated proteins that firmly tether to the extracellular plasma membrane leaflet of their producing cells. There, Hhs multimerize into light-microscopically visible signaling platforms. These platforms serve as storage for Hh multimers at the cell surface, but also recruit and activate factors required for their regulated release. However, the hierarchical assembly and molecular structure of Hh platforms as determinants of subsequent modes of Hh spreading and morphogen function are only poorly understood. We will thus characterize the molecular mechanisms that govern dynamic Hh platform assembly as well as Hh platform structure and molecular composition.