Seroatlas · Human Serome Atlas

SMN1

Survival motor neuron protein

Also known as: BCD541, GEMIN1, SMA, SMA@, SMA1, SMA2, SMA3, SMN_HUMAN, SMN2, SMNC, SMNT, TDRD16A, TDRD16B

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

Protein identityUniProt · HPA

UniProt accession
Q16637
Gene
SMN1
Ensembl
ENSG00000172062
Chromosome
5
Canonical length
294 aa
Protein class
Disease related genes, FDA approved drug targets, Human disease related genes, Predicted intracellular proteins
Subcellular location
Nuclear bodies,Cytosol
Quaternary structure
Homooligomer

OverviewNCBI Gene

This gene is part of a 500 kb inverted duplication on chromosome 5q13. This duplicated region contains at least four genes and repetitive elements which make it prone to rearrangements and deletions. The repetitiveness and complexity of the sequence have also caused difficulty in determining the organization of this genomic region. The telomeric and centromeric copies of this gene are nearly identical and encode the same protein. However, mutations in this gene, the telomeric copy, are associated with spinal muscular atrophy; mutations in the centromeric copy do not lead to disease. The centromeric copy may be a modifier of disease caused by mutation in the telomeric copy. The critical sequence difference between the two genes is a single nucleotide in exon 7, which is thought to be an exon splice enhancer. Note that the nine exons of both the telomeric and centromeric copies are designated historically as exon 1, 2a, 2b, and 3-8. It is thought that gene conversion events may involve the two genes, leading to varying copy numbers of each gene. The protein encoded by this gene localizes to both the cytoplasm and the nucleus. Within the nucleus, the protein localizes to subnuclear bodies called gems which are found near coiled bodies containing high concentrations of small ribonucleoproteins (snRNPs). This protein forms heteromeric complexes with proteins such as SIP1 and GEMIN4, and also interacts with several proteins known to be involved in the biogenesis of snRNPs, such as hnRNP U protein and the small nucleolar RNA binding protein. Multiple transcript variants encoding distinct isoforms have been described. [provided by RefSeq, Jul 2014]

Canonical amino-acid sequenceUniProt

294 residues, UniProt reviewed canonical sequence.

>Q16637|SMN1
     1  MAMSSGGSGG GVPEQEDSVL FRRGTGQSDD SDIWDDTALI KAYDKAVASF KHALKNGDIC
    61  ETSGKPKTTP KRKPAKKNKS QKKNTAASLQ QWKVGDKCSA IWSEDGCIYP ATIASIDFKR
   121  ETCVVVYTGY GNREEQNLSD LLSPICEVAN NIEQNAQENE NESQVSTDES ENSRSPGNKS
   181  DNIKPKSAPW NSFLPPPPPM PGPRLGPGKP GLKFNGPPPP PPPPPPHLLS CWLPPFPSGP
   241  PIIPPPPPIC PDSLDDADAL GSMLISWYMS GYHTGYYMGF RQNQKEGRCS HSLN

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SMN1 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)
0.59
Highest tissue expression
37 nTPM

Expression across tissuesHPA

Tissue

  • liver: 37 nTPM
  • ovary: 36 nTPM
  • skeletal muscle: 30 nTPM
  • cervix: 29 nTPM
  • cerebellum: 28 nTPM
  • spinal cord: 28 nTPM

Single-cell type

  • late spermatids: 17 nCPM
  • early spermatids: 17 nCPM
  • late primary spermatocytes: 15 nCPM
  • megakaryocytes: 12 nCPM
  • oocytes: 9.2 nCPM
  • retinal pigment epithelial cells: 8.5 nCPM

Immune cell

  • MAIT T-cell: 18 nTPM
  • T-reg: 16 nTPM
  • naive CD8 T-cell: 15 nTPM
  • non-classical monocyte: 14 nTPM
  • memory B-cell: 13 nTPM
  • naive CD4 T-cell: 13 nTPM

Brain region

  • cerebellum: 12 nTPM
  • hypothalamus: 12 nTPM
  • medulla oblongata: 9.8 nTPM
  • white matter: 9.6 nTPM
  • hippocampal formation: 9.3 nTPM
  • cerebral cortex: 9.1 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about SMN1.

Disease | AllUniProt

Conditions SMN1 is implicated in, by any mechanism.

Disease | GeneticClinVar

84 pathogenic / likely-pathogenic of 170 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

  • Werdnig-Hoffmann disease
  • Kugelberg-Welander disease
  • Spinal muscular atrophy
  • Spinal muscular atrophy, type II
  • Spinal muscular atrophy, type IV

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)
1.93
gnomAD pLI
0.02
gnomAD missense Z
0.06

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 SMN1 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 SMN1 as an antibody target. Whether an autoantibody or antibody against SMN1 could matter depends on whether native SMN1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SMN1 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 SMN1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/SMN1. 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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