SMAD family member 6 (SMAD6)

SMAD family member 6, also known as SMAD6 is a protein that, as its name describes, is a homolog of the Drosophila gene "mothers against decapentaplegic". It belongs to the SMAD family of proteins, which belong to the TGF beta superfamily of modulators.

Like many other TGF beta family members SMAD6 is involved in cell signalling. It acts as a regulator of TGF beta family (such as bone morphogenetic proteins) activity by competing with SMAD4 and preventing the transcription of SMAD4's gene products. There are two known isoforms of this protein.The SMAD proteins are homologs of both the drosophila protein, mothers against decapentaplegic (MAD) and the C. elegans protein SMA. The name is a combination of the two.