Mothers against decapentaplegic homolog 3

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SMAD, Mothers against decapentaplegic homolog 3
Crystal Structure Of The Phosphorylated Smad3SMAD4 Heterotrimeric Complex
Other names:	SMAD 3 , Mothers against DPP homolog 3, Mad3, hMAD-3, JV15-2, hSMAD3
Genetic data
Gene code:	HUGO code:SMAD3
Protein Structure/Function
Protein type:	R-SMAD
Functions:	signal transduction, transcription regulator
Domains:	MH1, MH2
Other
Taxa expressing:	Homo sapiens; homologous proteins many metazoan phyla
Subcellular localization:	Primary:nucleus, Alternative:cytoplasm
Covalent modifications:	phosphorylation
Related information
Recent publications:	TGFβ signal transduction

SMAD3 or Mothers against decapentaplegic homolog 3 is a polypeptide that, as its name describes, is a homolog of the Drosophila protein: "Mothers against decepentaplegic". It belongs to the SMAD family of proteins, which belong to the TGFβ superfamily of modulators. Like many other TGFβ family members SMAD3 is involved in cell signalling. SMAD3 modulates signals of activin and TGFβ's. Binding of this protein with SMAD4 enables its transmigration into the nucleus where it forms complexes with other proteins and acts as a transcription factor. SMAD3 is a receptor regulated SMAD (R-SMAD).

[edit] Nomenclature

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. During Drosophila research, it was found that a mutation in the gene, MAD, in the mother, repressed the gene, decapentaplegic, in the embryo. The phrase "Mothers against" was added since mothers often form organizations opposing various issues eg. Mothers Against Drunk Driving or (MADD).

Identifiers
Symbol	SMAD3 MADH3
HUGO	6769
Entrez	4088
OMIM	603109
RefSeq	NM_005902
UniProt	P84022
Other data
Locus	Chr. 15 q22.33