Indian hedgehog protein (IHH, MEROPS identifier C46.003) is important for the development and growth of bone and cartilage in the embryo []. IHH is synthesized as a precursor and activates itself by cleavage of Gly-Cys bond, in which the thiol group of the cysteine is the nucleophile []. This results in the release of the N-terminal effector domain, and no further proteolytic activity takes place. The differentiation of chondrocytes in embryonic mouse limbs, induction of the expression of nodal in the lateral plate mesoderm of early chick embryos, and affinities for hedgehog-binding proteins have been compared for Sonic, Indian and Desert hedgehog proteins [].
