SMAD family member 6, also known as SMAD6, is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...

that in humans is encoded by the ''SMAD6''

gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...

. SMAD6 is a protein that, as its name describes, is a homolog of the

Drosophila ''Drosophila'' () is a genus of flies, belonging to the family Drosophilidae, whose members are often called "small fruit flies" or (less frequently) pomace flies, vinegar flies, or wine flies, a reference to the characteristic of many speci ...

gene "

mothers against decapentaplegic Mothers against decapentaplegic is a protein from the SMAD family that was discovered in ''Drosophila''. During ''Drosophila'' research, it was found that a mutation in the gene in the mother repressed the gene decapentaplegic in the embryo. The ...

". It belongs to the SMAD family of proteins, which belong to the TGFβ superfamily of modulators. Like many other TGFβ family members SMAD6 is involved in

cell signalling In biology, cell signaling (cell signalling in British English) or cell communication is the ability of a cell to receive, process, and transmit signals with its environment and with itself. Cell signaling is a fundamental property of all cellular ...

. It acts as a regulator of TGFβ family (such as

bone morphogenetic proteins Bone morphogenetic proteins (BMPs) are a group of growth factors also known as cytokines and as metabologens. Originally discovered by their ability to induce the formation of bone and cartilage, BMPs are now considered to constitute a group of p ...

) activity by competing with SMAD4 and preventing the transcription of SMAD4's gene products. There are two known isoforms of this protein.

Nomenclature

The SMAD proteins are homologs of both the drosophila protein, mothers against decapentaplegic (MAD) and the ''

C. elegans ''Caenorhabditis elegans'' () is a free-living transparent nematode about 1 mm in length that lives in temperate soil environments. It is the type species of its genus. The name is a blend of the Greek ''caeno-'' (recent), ''rhabditis'' (r ...

'' 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 Decapentaplegic (Dpp) is a key morphogen involved in the development of the fruit fly '' Drosophila melanogaster'' and is the first validated secreted morphogen. It is known to be necessary for the correct patterning and development of the early ...

'' in the embryo. The phrase "Mothers against" was added as a humorous take-off on organizations opposing various issues e.g.,

Mothers Against Drunk Driving Mothers Against Drunk Driving (MADD) is a non-profit organization in the United States, Canada and Brazil that seeks to stop drunk driving, support those affected by drunk driving, prevent underage drinking, and strive for stricter impaired drivin ...

, or MADD; and based on a tradition of such unusual naming within the gene research community.

Disease associations

Heterozygous, damaging mutations in SMAD6 are the most frequent genetic cause of non-syndromic

craniosynostosis Craniosynostosis is a condition in which one or more of the fibrous sutures in a young infant's skull prematurely fuses by turning into bone (ossification), thereby changing the growth pattern of the skull. Because the skull cannot expand perpe ...

identified to date.

Interactions

Mothers against decapentaplegic homolog 6 has been shown to

interact Advocates for Informed Choice, doing business as, dba interACT or interACT Advocates for Intersex Youth, is a 501(c)(3) nonprofit organization using innovative strategies to advocate for the legal and human rights of children with intersex trai ...

with: *

HOXC8 Homeobox protein Hox-C8 is a protein that in humans is encoded by the ''HOXC8'' gene. Function This gene belongs to the homeobox family of genes. The homeobox genes encode a highly conserved family of transcription factors that play an import ...

, * MAP3K7, * Mothers against decapentaplegic homolog 7, * PIAS4, and *

STRAP A strap, sometimes also called strop, is an elongated flap or ribbon, usually of leather or other flexible materials. Thin straps are used as part of clothing or baggage, or bedding such as a sleeping bag. See for example spaghetti strap, ...

Nomenclature

Disease associations

Interactions

References

Further reading