An Inhibin Coreceptor

Science's STKE  28 Mar 2000:
Vol. 2000, Issue 25, pp. tw4
DOI: 10.1126/stke.2000.25.tw4

Activin and inhibin both belong to the transforming growth factor-beta (TGF-β) family of growth and differentiation factors, yet they have an antagonistic relation in regulating certain processes. The antagonism is based on competition between inhibin and activin to bind the activin receptor ActRII. However, in some instances, inhibin fails to antagonize activin, and Lewis et al. report that one possible reason could be the absence of the proteoglycan betaglycan. Betaglycan appears to act as a coreceptor with ActRII for binding inhibin. The authors suggest that the inhibin-betaglycan complex competes with activin for access to ActRII and, therefore, prevents initiation of the activin signaling cascade.

Lewis, K.A., Gray, P.C., Blount, A.L., MacConell, L.A., Wiater, E., Bilesikjian, L.M., and Vale, W. (2000) Betaglycan binds inhibin and can mediate functional antagonism of activin signalling. Nature 404: 411-414. [Online Journal]