Shisa is a transcription factor-type molecule that physically interacts with immature forms of the Wnt receptor Frizzled and the FGF receptor within the endoplasmic reticulum to inhibit their post-translational maturation and trafficking to the cell surface.

1: Shisa promotes head formation through the inhibition of receptor protein maturation for the caudalizing factors, Wnt and FGF. Yamamoto A, Nagano T, Takehara S, Hibi M, Aizawa S; Cell. 2005;120:223-235. PMID:15680328

2: Expression of Shisa2, a modulator of both Wnt and Fgf signaling, in the chick embryo. Hedge TA, Mason I; Int J Dev Biol. 2008;52:81-85. PMID:18033675