Seroatlas · Human Serome Atlas

SMAD1

Mothers against decapentaplegic homolog 1

Also known as: JV4-1, MADH1, MADR1, SMAD1_HUMAN

Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene

Protein identityUniProt · HPA

UniProt accession
Q15797
Gene
SMAD1
Ensembl
ENSG00000170365
Chromosome
4
Canonical length
465 aa
Protein class
Cancer-related genes, Disease related genes, Predicted intracellular proteins, Transcription factors
Subcellular location
Nucleoplasm,Cytosol

OverviewNCBI Gene

The protein encoded by this gene belongs to the SMAD, a family of proteins similar to the gene products of the Drosophila gene 'mothers against decapentaplegic' (Mad) and the C. elegans gene Sma. SMAD proteins are signal transducers and transcriptional modulators that mediate multiple signaling pathways. This protein mediates the signals of the bone morphogenetic proteins (BMPs), which are involved in a range of biological activities including cell growth, apoptosis, morphogenesis, development and immune responses. In response to BMP ligands, this protein can be phosphorylated and activated by the BMP receptor kinase. The phosphorylated form of this protein forms a complex with SMAD4, which is important for its function in the transcription regulation. This protein is a target for SMAD-specific E3 ubiquitin ligases, such as SMURF1 and SMURF2, and undergoes ubiquitination and proteasome-mediated degradation. Alternatively spliced transcript variants encoding the same protein have been observed. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

465 residues, UniProt reviewed canonical sequence.

>Q15797|SMAD1
     1  MNVTSLFSFT SPAVKRLLGW KQGDEEEKWA EKAVDALVKK LKKKKGAMEE LEKALSCPGQ
    61  PSNCVTIPRS LDGRLQVSHR KGLPHVIYCR VWRWPDLQSH HELKPLECCE FPFGSKQKEV
   121  CINPYHYKRV ESPVLPPVLV PRHSEYNPQH SLLAQFRNLG QNEPHMPLNA TFPDSFQQPN
   181  SHPFPHSPNS SYPNSPGSSS STYPHSPTSS DPGSPFQMPA DTPPPAYLPP EDPMTQDGSQ
   241  PMDTNMMAPP LPSEINRGDV QAVAYEEPKH WCSIVYYELN NRVGEAFHAS STSVLVDGFT
   301  DPSNNKNRFC LGLLSNVNRN STIENTRRHI GKGVHLYYVG GEVYAECLSD SSIFVQSRNC
   361  NYHHGFHPTT VCKIPSGCSL KIFNNQEFAQ LLAQSVNHGF ETVYELTKMC TIRMSFVKGW
   421  GAEYHRQDVT STPCWIEIHL HGPLQWLDKV LTQMGSPHNP ISSVS

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SMAD1 can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability
Intracellular
Secreted
No
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.37
Highest tissue expression
31 nTPM

Expression across tissuesHPA

Tissue

  • epididymis: 31 nTPM
  • smooth muscle: 28 nTPM
  • parathyroid gland: 27 nTPM
  • endometrium: 27 nTPM
  • skin: 23 nTPM
  • fallopian tube: 23 nTPM

Single-cell type

  • lymphatic endothelial cells: 529 nCPM
  • early spermatids: 304 nCPM
  • vascular endothelial cells: 172 nCPM
  • pituitary stem cells: 158 nCPM
  • lactotrophs: 131 nCPM
  • renal collecting duct principal cells: 128 nCPM

Immune cell

  • basophil: 47 nTPM
  • non-classical monocyte: 22 nTPM
  • intermediate monocyte: 9.4 nTPM
  • myeloid DC: 6.8 nTPM
  • classical monocyte: 3.6 nTPM
  • NK-cell: 2.4 nTPM

Brain region

  • basal ganglia: 52 nTPM
  • midbrain: 46 nTPM
  • hypothalamus: 42 nTPM
  • thalamus: 42 nTPM
  • amygdala: 42 nTPM
  • cerebellum: 38 nTPM

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance)
0.27
gnomAD pLI
0.99
gnomAD missense Z
2.28
DepMap mean gene effect
0.12
DepMap dependency class
none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 4% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of SMAD1 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads SMAD1 as an antibody target. Whether an autoantibody or antibody against SMAD1 could matter depends on whether native SMAD1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SMAD1 is annotated as predominantly intracellular. Intracellular proteins are common autoantibody markers, becoming visible to the immune system after cell injury or altered processing, but are usually markers of disease rather than direct drivers.

Annotation status

The present source text does not explicitly label SMAD1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/SMAD1. Study-independent annotations aggregated from UniProt, Human Protein Atlas, PubMed, IEDB, Pfam, InterPro, Gene Ontology, AlphaFold, gnomAD, DepMap, ClinVar, TCGA. Catalog release seroatlas-reviewed-human-uniprot-20260313.

Seroatlas is the reference for exploring autoantibody and antibody serology at the human-protein level: the autoreactome and human serome, multiplex serology (HuProt, HuScan, VirScan, PhIP-Seq).

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