Cornichon Homolog 2 (CNIH2)

Like Drosophila cni, the deduced CNIH2 proteins in mouse, human, and chicken contain 3 putative transmembrane domains and a predicted C-terminal cytoplasmic COPII-interacting domain; unlike Drosophila cni, they all contain a highly conserved 16-amino acid sequence. Both the human and mouse proteins contain 160 amino acids.

Injection of a truncated form of CNIH2 that lacked the predicted C-terminal cytoplasmic loop into chick embryos resulted in disruption of the normal distribution of cranial neural crest cells (NCCs), which, in turn, caused abnormal fiber connections between cranial sensory ganglia. Knockdown of CNIH2 or HBEGF with siRNA produced a similar phenotype, which is also similar to that seen in ErbB4 knockout mice.