Decrypting the role of Cripto in tumorigenesis
J. Clin. Invest. Michael M. Shen, et al. 112:500 doi:10.1172/JCI19546 [
Go to this article.]

Figure 1Schematic models for the role of Cripto in Activin and Nodal signaling. For simplicity, TGF-β ligands and receptors are represented as monomers. (
a) Activin signaling utilizes ActRIB and ActRII or ActRIIB, resulting in an active receptor complex and phosphorylation (P) of the type I receptor. (
b) Nodal signaling requires Cripto, which is GPI-linked, in addition to ActRIB and ActRIIB. Nodal interacts with Cripto through the EGF motif, and requires the presence of an
O-fucose modification (red
F) on Cripto. (
c–
f) Four possible inactive complexes resulting in inhibition of Activin signaling by Cripto. Gray and colleagues (
12) propose an inactive Cripto/Activin/ActRII complex (
c) and do not detect direct interaction between Cripto and Activin (
f). In contrast, Adkins and colleagues (
1) propose three potential inactive complexes that do not include ActRII (
d–f).