The Hedgehog signaling pathway is a signaling pathway that transmits information to embryonic cells required for proper cell differentiation.
Mammals have three Hedgehog homologues, Desert (DHH), Indian (IHH), and Sonic (SHH), of which Sonic is the best studied.[1] The pathway is equally important during vertebrate embryonic development and is therefore of interest in evolutionary developmental biology.
Protein patched homolog 1 (Ptch1) acts as receptor of Sonic Hedgehog protein (Shh) which is involved in formation of embryonic structures [2]. Embryogenesis is regulated by several pathways one of which is the Shh-Patch1-Gli all of which are highly conserved.
Mutations in Ptch1 are associated with holoprosencephaly[3].
High expression of Ptch1 messenger RNA indicates a risk of postresection recurrence of hepatocellular carcinoma[4].
. Ptch1 (residues 772-1023). . Ptch1 ectodomain 1 (colored in salmon) interacts with Shh as well as Ptch1 ectodomain 2 (colored in wheat) with . The Ptch1-Shh interaction is steroid-dependent and the 3D structure shows [5].