Ectodermin:

A Ring-type ubiquitin ligase for Smad4, serving as a vital regulator of the transforming growth factor– beta (TGF-beta)/BMP signaling pathway in early embryonic development and cancer.

Mechanism

As Smad4 is the Comediator Smad and facilitates the translocation of the R-Smads into the nucleus, ectodermin forces Smad4 out of the nucleus and promotes its degradation.Through this regulation of the TGF-beta signaling, ectodermin keeps ectoderm cells pluripotent until gastrulation and ensures that ectoderm cells do not undertake mesoderm fate. Ectodermin is also important in reducing TGF-beta/Smad4 induced cytostasis as Ectodermin is expressed in the stem cells of colorectal cancer and intestinal crypts.