Shisa is a transmembrane, transcription factor-type protein 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 [, ].The Shisa family founding member, Xenopus Shisa, promotes head development by antagonising Wnt and FGF signaling []. Several vertebrate homologues have been identified with implicated roles in development, cancer and apoptosis [, , ]. Distantly related Shisa homologues have also been detected that possess an N-terminal domain with six conserved cysteines. These Shisa-like proteins include SHISAL1 (shisa-like-1, also known as KIAA1644), SHISAL2A (FAM159A) and SHISAL2B (FAM159B) from vertebrates [].
