SHH, human: Sonic Hedgehog (SHH) is one of three proteins of the Hedgehog (Hh) family, which also contains Desert Hedgehog (DHH) and Indian Hedgehog (IHH). The three members share a high degree of amino-acid sequence identity (e.g., SHH and IHH are 93 % identical).
SHH is expressed in fetal intestine, liver, lung, and kidney, but not in adult tissues. The protein consists of 462 a.a. with a 23 a.a. signal peptide at N-terminus and is further cleaved into SHH N-Terminus and C-Terminus.
SHH has the most critical roles in development, acting as a morphogen involved in patterning many systems, including the limb and midline structures in the brain, spinal cord, the thalamus by the zona limitans intrathalamica and the teeth.
In the absence of Sonic Hedgehog, patched receptor represses the constitutive signaling activity of smoothened.
SHH-N retains all known signaling capabilities and can be lipid-modified without receptor affinity reducing but has more potent than the unmodified form.
The rHuSHH has an N-terminal Ile-Val-Ile sequence substituted for the natural occurring chemically modified Cys residue., UnitProt ID: Q15465