Mothers against decapentaplegic homolog 9

Mothers against decapentaplegic homolog 9 also known as SMAD9, SMAD8, and MADH6 is a protein that in humans is encoded by the SMAD9 gene.^[5]

SMAD9
Identifiers
Aliases	SMAD9, MADH6, MADH9, PPH2, SMAD8, SMAD8A, SMAD8B, SMAD8/9, SMAD family member 9
External IDs	OMIM: 603295; MGI: 1859993; HomoloGene: 21198; GeneCards: SMAD9; OMA:SMAD9 - orthologs
Gene location (Human) Chr. Chromosome 13 (human)[1] Band 13q13.3 Start 36,844,831 bp[1] End 36,920,765 bp[1]
Gene location (Mouse) Chr. Chromosome 3 (mouse)[2] Band 3|3 C Start 54,663,003 bp[2] End 54,708,678 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in corpus epididymis caput epididymis urethra tail of epididymis seminal vesicula spinal ganglia trigeminal ganglion subthalamic nucleus endometrium superficial temporal artery Top expressed in female urethra yolk sac primary visual cortex genital tubercle cerebellar cortex superior frontal gyrus lumbar subsegment of spinal cord amnion chorion dentate gyrus of hippocampal formation granule cell More reference expression data BioGPS n/a
Gene ontology Molecular function DNA binding DNA-binding transcription factor activity metal ion binding protein binding DNA-binding transcription factor activity, RNA polymerase II-specific Cellular component SMAD protein complex transcription regulator complex intracellular anatomical structure nucleoplasm nucleus cytoplasm cytosol Biological process ureteric bud development regulation of transcription, DNA-templated SMAD protein signal transduction cellular response to organic cyclic compound hindbrain development cellular response to BMP stimulus BMP signaling pathway transcription, DNA-templated protein phosphorylation cartilage development bone development transforming growth factor beta receptor signaling pathway midbrain development positive regulation of transcription from RNA polymerase II promoter involved in cellular response to chemical stimulus Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 4093 55994 Ensembl ENSG00000120693 ENSMUSG00000027796 UniProt O15198 Q9JIW5 RefSeq (mRNA) NM_001127217 NM_005905 NM_001378621 NM_019483 RefSeq (protein) NP_001120689 NP_005896 NP_001365550 NP_062356 Location (UCSC) Chr 13: 36.84 – 36.92 Mb Chr 3: 54.66 – 54.71 Mb PubMed search [3] [4]
Wikidata
View/Edit Human View/Edit Mouse

SMAD9, 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 TGFβ superfamily of modulators. Like many other TGFβ family members, SMAD9 is involved in cell signalling. When a bone morphogenetic protein binds to a receptor (BMP type 1 receptor kinase) it causes SMAD9 to interact with SMAD anchor for receptor activation (SARA).The binding of ligands causes the phosphorylation of the SMAD9 protein and the dissociation from SARA and the association with SMAD4. It is subsequently transferred to the nucleus where it forms complexes with other proteins and acts as a transcription factor. SMAD9 is a receptor regulated SMAD (R-SMAD) and is activated by bone morphogenetic protein type 1 receptor kinase. There are two isoforms of the protein. Confusingly, it is also sometimes referred to as SMAD8 in the literature.

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 e.g. Mothers Against Drunk Driving or (MADD); and based on a tradition of such unusual naming within the gene research community.^[6]

References

1. GRCh38: Ensembl release 89: ENSG00000120693 – Ensembl, May 2017
2. GRCm38: Ensembl release 89: ENSMUSG00000027796 – Ensembl, May 2017
3. "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
4. "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
5. Watanabe TK, Suzuki M, Omori Y, Hishigaki H, Horie M, Kanemoto N, Fujiwara T, Nakamura Y, Takahashi E (June 1997). "Cloning and characterization of a novel member of the human Mad gene family (MADH6)". Genomics. 42 (3): 446–51. doi:10.1006/geno.1997.4753. PMID 9205116.
6. "Sonic Hedgehog, DICER, and the Problem With Naming Genes", Sep 26, 2014, Michael White. psmag.com