Hedgehog signaling pathway ligand involved in regulating vertebrate organogenesis.
Human recombinant Sonic Hedgehog is biologically active as compared to a standard. The ED₅₀, measured by the dose-dependent induction of alkaline phosphatase production by C3H/10T1/2 fibroblasts, is 750ng/ml.
Recombinant Human Sonic Hedgehog (SHH) is a highly conserved protein that plays an important role in embryonic development. It is expressed in neural tissue, the gut, and areas of limb development and promotes differentiation and growth in a tissue-specific manner. SHH is synthesized as a 45-kDa precursor protein, which is then cleaved to generate the active 19-kDa N-terminus. SHH interacts with the Patched and Smoothened transmembrane receptors, leading to the activation of GLI family transcription factors. Disruption of any part of this pathway during embryogenesis is associated with birth defects ranging from mild to severe. In adults, abnormal activation of the SHH pathway has been implicated in several forms of cancer. Three mammalian hedgehog genes (sonic, desert, Indian) share about 60% homology. The Cys at position 25 has been substituted with Ile. Human SHH is a non-glycosylated polypeptide consisting of 175 amino acids with a molecular weight of 19,697 Da.