Human SHH

SHH (Sonic Hedgehog) is expressed in embryonic tissues critical for the patterning of the developing central nervous system, somite, and limb, and it is also involved in whisker, hair, foregut, tooth, and bone development. In adult tissue SHH is associated with cancer development and tissue remodeling following injury. Human Shh encoding a 462 amino acid (aa) precursor protein is autocatalytically processed to yield a non-glycosylated 19 kDa N-terminal fragment (Shh-N) and a glycosylated 25 kDa C-terminal protein (Shh-C). Canonical signaling of Shh is mediated by a multicomponent receptor complex that includes Patched (PTCH1, PTCH2) and Smoothened (SMO). Shh binding to PTCH releases the basal repression of SMO by PTCH. In addition, Shh activity can also be regulated through interactions with heparin, glypicans, and membrane-associated Hip (hedgehog interacting protein) (1-5).