Seroatlas · Human Serome Atlas

SMIM43

Small integral membrane protein 43

Also known as: SIM43_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
Q4W5P6
Gene
SMIM43
Ensembl
ENSG00000164112
Chromosome
4
Canonical length
63 aa
Protein class
Predicted intracellular proteins

OverviewNCBI Gene

Enables transmembrane transporter binding activity. Predicted to be involved in mesendoderm development. Predicted to be located in plasma membrane. [provided by Alliance of Genome Resources, Apr 2025]

Canonical amino-acid sequenceUniProt

63 residues, UniProt reviewed canonical sequence.

>Q4W5P6|SMIM43
     1  MEWELNLLLY LALFFFLLFL LFLLLFVVIK QLKNSVANTA GALQPGRLSV HREPWGFSRE
    61  QAV

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SMIM43 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
Cell surface
Secreted
No
Transmembrane segments
1
Mean surface accessibility (rSASA)
0.58
Highest tissue expression
10 nTPM

Expression across tissuesHPA

Tissue

  • cerebral cortex: 10 nTPM
  • amygdala: 1.4 nTPM
  • hippocampal formation: 1.2 nTPM
  • colon: 0.7 nTPM
  • placenta: 0.4 nTPM
  • hypothalamus: 0.3 nTPM

Single-cell type

  • cytotrophoblasts: 23 nCPM
  • brain excitatory neurons: 8.9 nCPM
  • syncytiotrophoblasts: 5.9 nCPM
  • migrating cytotrophoblasts: 4.5 nCPM
  • schwann cells: 2.6 nCPM
  • brain inhibitory neurons: 2.1 nCPM

Immune cell

  • basophil: 0 nTPM
  • classical monocyte: 0 nTPM
  • eosinophil: 0 nTPM
  • gdT-cell: 0 nTPM
  • intermediate monocyte: 0 nTPM
  • MAIT T-cell: 0 nTPM

Brain region

  • cerebral cortex: 26 nTPM
  • white matter: 9.8 nTPM
  • hippocampal formation: 7.6 nTPM
  • basal ganglia: 7.4 nTPM
  • hypothalamus: 4.4 nTPM
  • amygdala: 3.3 nTPM

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 3% 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

  • Small integral membrane protein 43
  • Small integral membrane protein 43

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of SMIM43 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 SMIM43 as an antibody target. Whether an autoantibody or antibody against SMIM43 could matter depends on whether native SMIM43 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SMIM43 is annotated at the cell surface, where native SMIM43 is exposed to circulating antibodies and is a prime autoantibody target that could block, deplete, or overstimulate it.

Annotation status

The present source text does not explicitly label SMIM43 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/SMIM43. 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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