Seroatlas · Human Serome Atlas

SMIM13

Small integral membrane protein 13

Also known as: C6orf228, SIM13_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
P0DJ93
Gene
SMIM13
Ensembl
ENSG00000224531
Chromosome
6
Canonical length
91 aa
Protein class
Predicted membrane proteins
Subcellular location
Nucleoplasm,Nuclear membrane,Golgi apparatus

OverviewNCBI Gene

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

Canonical amino-acid sequenceUniProt

91 residues, UniProt reviewed canonical sequence.

>P0DJ93|SMIM13
     1  MWHSVGLTLL VFVATLLIVL LLMVCGWYFV WHLFLSKFKF LRELVGDTGS QEGDHEPSGS
    61  ETEEDTSSSP HRIRSARQRR APADEGHRPL T

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SMIM13 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)
0.61
Highest tissue expression
28 nTPM

Expression across tissuesHPA

Tissue

  • cerebellum: 28 nTPM
  • cerebral cortex: 26 nTPM
  • spinal cord: 17 nTPM
  • retina: 16 nTPM
  • midbrain: 14 nTPM
  • hypothalamus: 14 nTPM

Single-cell type

  • syncytiotrophoblasts: 95 nCPM
  • basal keratinocytes: 79 nCPM
  • cone photoreceptor cells: 58 nCPM
  • extravillous trophoblasts: 50 nCPM
  • migrating cytotrophoblasts: 48 nCPM
  • thyrotrophs: 48 nCPM

Immune cell

  • plasmacytoid DC: 0.4 nTPM
  • basophil: 0.3 nTPM
  • gdT-cell: 0.1 nTPM
  • MAIT T-cell: 0.1 nTPM
  • myeloid DC: 0.1 nTPM
  • naive CD8 T-cell: 0.1 nTPM

Brain region

  • cerebellum: 40 nTPM
  • thalamus: 38 nTPM
  • cerebral cortex: 37 nTPM
  • pons: 36 nTPM
  • white matter: 36 nTPM
  • hypothalamus: 34 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)
1.57
gnomAD pLI
0.19
gnomAD missense Z
0.69
DepMap mean gene effect
0.14
DepMap dependency class
none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 8% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Cellular components

Protein domainsUniProt · Pfam · InterPro

  • Protein of unknown function DUF4750
  • Domain of unknown function (DUF4750)

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads SMIM13 as an antibody target. Whether an autoantibody or antibody against SMIM13 could matter depends on whether native SMIM13 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SMIM13 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 SMIM13 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/SMIM13. 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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