Seroatlas · Human Serome Atlas

SMIM27

Small integral membrane protein 27

Also known as: C9orf133, SIM27_HUMAN, TOPORS-AS1

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

Protein identityUniProt · HPA

UniProt accession
A0A1B0GUW7
Gene
SMIM27
Ensembl
ENSG00000235453
Chromosome
9
Canonical length
55 aa
Protein class
Predicted intracellular proteins, Predicted membrane proteins

OverviewNCBI Gene

Predicted to be located in membrane. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

55 residues, UniProt reviewed canonical sequence.

>A0A1B0GUW7|SMIM27
     1  MKPVSRRTLD WIYSVLLLAI VLISWGCIIY ASMVSARRQL RKKYPDKIFG TNENL

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SMIM27 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
Unknown
Secreted
No
Transmembrane segments
1
Mean surface accessibility (rSASA)
0.58
Highest tissue expression
39 nTPM

Expression across tissuesHPA

Tissue

  • choroid plexus: 39 nTPM
  • testis: 36 nTPM
  • skeletal muscle: 30 nTPM
  • pancreas: 27 nTPM
  • tongue: 24 nTPM
  • thymus: 24 nTPM

Single-cell type

  • early spermatids: 422 nCPM
  • late primary spermatocytes: 364 nCPM
  • late spermatids: 234 nCPM
  • platelets: 152 nCPM
  • parietal cells: 143 nCPM
  • cardiomyocytes: 116 nCPM

Immune cell

  • neutrophil: 758 nTPM
  • eosinophil: 363 nTPM
  • naive CD4 T-cell: 146 nTPM
  • T-reg: 138 nTPM
  • naive B-cell: 137 nTPM
  • memory B-cell: 132 nTPM

Brain region

  • white matter: 27 nTPM
  • spinal cord: 23 nTPM
  • hypothalamus: 23 nTPM
  • cerebellum: 23 nTPM
  • cerebral cortex: 22 nTPM
  • medulla oblongata: 22 nTPM

OntologyGO

Cellular components

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads SMIM27 as an antibody target. Whether an autoantibody or antibody against SMIM27 could matter depends on whether native SMIM27 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SMIM27 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 SMIM27 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/SMIM27. 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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