Seroatlas · Human Serome Atlas

SMIM33

Small integral membrane protein 33

Also known as: SIM33_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
A0A1B0GW64
Gene
SMIM33
Ensembl
ENSG00000283288
Chromosome
5
Canonical length
132 aa
Protein class
Predicted membrane proteins

OverviewNCBI Gene

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

Canonical amino-acid sequenceUniProt

132 residues, UniProt reviewed canonical sequence.

>A0A1B0GW64|SMIM33
     1  MHQAGHYSWP SPAVNSSSEQ EPQRQLPEVL SGTWEQPRVD GLPVVTVIVA VFVLLAVCII
    61  VAVHFGPRLH QGHATLPTEP PTPKPDGGIY LIHWRVLGPQ DSPEEAPPGP LVPGSCPAPD
   121  GPRPSIDEVT CL

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SMIM33 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)
0.66
Highest tissue expression
3.4 nTPM

Expression across tissuesHPA

Tissue

  • rectum: 3.4 nTPM
  • salivary gland: 2.8 nTPM
  • colon: 2.4 nTPM
  • small intestine: 1 nTPM
  • cervix: 0.9 nTPM
  • appendix: 0.4 nTPM

Single-cell type

  • ependymal cells: 0.1 nCPM
  • goblet cells: 0.1 nCPM
  • adipocytes: 0 nCPM
  • adrenal cortex cells: 0 nCPM
  • adrenal medulla cells: 0 nCPM
  • alveolar cells type 1: 0 nCPM

Immune cell

  • memory CD4 T-cell: 1.2 nTPM
  • memory CD8 T-cell: 0.9 nTPM
  • gdT-cell: 0.7 nTPM
  • MAIT T-cell: 0.6 nTPM
  • T-reg: 0.6 nTPM
  • plasmacytoid DC: 0.5 nTPM

Brain region

  • amygdala: 0 nTPM
  • basal ganglia: 0 nTPM
  • cerebellum: 0 nTPM
  • cerebral cortex: 0 nTPM
  • choroid plexus: 0 nTPM
  • hippocampal formation: 0 nTPM

OntologyGO

Cellular components

Protein domainsUniProt · Pfam · InterPro

  • Small integral membrane protein 33

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads SMIM33 as an antibody target. Whether an autoantibody or antibody against SMIM33 could matter depends on whether native SMIM33 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SMIM33 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 SMIM33 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/SMIM33. 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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