Protein modifications in Hedgehog signaling: Cross talk and feedback regulation confer divergent Hedgehog signaling activity.

The complexity of the Hedgehog (Hh) signaling cascade has increased over the course of evolution; however, it does not suffice to accommodate the dynamic yet robust requirements of differential Hh signaling activity needed for embryonic development and adult homeostatic maintenance. One solution to solve this dilemma is to apply multiple forms of post-translational modifications (PTMs) to the core Hh signaling components, modulating their abundance, localization, and signaling activity. This review summarizes various forms of protein modifications utilized to regulate Hh signaling, with a special emphasis on crosstalk between different forms of PTMs and their feedback regulation by Hh signaling.